UNITED STATES DISTRICT COURT

FOR THE DISTRICT OF COLUMBIA

)

IN RE POLAR BEAR ENDANGERED )

SPECIES ACT LISTING AND § 4(d) )

RULE LITIGATION ) Misc. No. 08-764 (EGS)

) MDL Docket No. 1993

)

)

This Document Relates To: )

)

Ctr. for Biological Diversity, )

et al. v. Salazar,1 et al., )

No. 08-2113; State of Alaska )

v. Salazar, et al., No. 08-1352; )

Safari Club Int’l, et al. v. )

Salazar, et al., No. 08-1550; )

California Cattlemen’s Ass’n, )

et al. v. Salazar, et al., No. )

08-1689; Conservation Force, )

et al. v. Salazar, et al., No. )

09-245 )

)

MEMORANDUM OPINION

In May 2008, the U.S. Fish and Wildlife Service (“FWS” or 

“the Service”) issued its final rule listing the polar bear as a 

“threatened species” under the Endangered Species Act of 1973. 

See Determination of Threatened Status for the Polar Bear (Ursus 

maritimus) Throughout Its Range, 73 Fed. Reg. 28,212 (May 15, 

2008) (the “Listing Rule”). The Service concluded that the 

polar bear is likely to become endangered within the foreseeable 

 1 Pursuant to Fed. R. Civ. P. 25(d), Interior Secretary Ken 

Salazar is automatically substituted as a defendant for his 

predecessor, Dirk Kempthorne, who was sued in his official 

capacity. 
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future because of anticipated impacts to its sea ice habitat 

from increasing Arctic temperatures, which have been attributed 

to global greenhouse gas emissions and related atmospheric 

changes. Numerous plaintiffs have challenged the Listing Rule 

under the Endangered Species Act (“ESA” or “the Act”), 16 U.S.C. 

§§ 1531-1544, and the Administrative Procedure Act (“APA”), 5 

U.S.C. §§ 551-559, 701-706, claiming that the Service’s decision 

to list the polar bear as a threatened species was arbitrary and 

capricious and an abuse of agency discretion. Pending before 

the Court are the parties’ cross-motions for summary judgment. 

As the briefing in this case makes clear, the question of

whether, when, and how to list the polar bear under the ESA is a 

uniquely challenging one. The three-year effort by FWS to 

resolve this question required agency decision-makers and 

experts not only to evaluate a body of science that is both 

exceedingly complex and rapidly developing, but also to apply 

that science in a way that enabled them to make reasonable 

predictions about potential impacts over the next century to a 

species that spans international boundaries. In this process, 

the Service considered over 160,000 pages of documents and 

approximately 670,000 comment submissions from state and federal 

agencies, foreign governments, Alaska Native Tribes and tribal 

organizations, federal commissions, local governments, 

commercial and trade organizations, conservation organizations, 
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nongovernmental organizations, and private citizens. In 

addition to relying on its own experts, the agency also 

consulted a number of impartial experts in a variety of fields, 

including climate scientists and polar bear biologists. 

In view of these exhaustive administrative proceedings, the 

Court is keenly aware that this is exactly the kind of decisionmaking process in which its role is strictly circumscribed. 

Indeed, it is not this Court’s role to determine, based on its 

independent assessment of the scientific evidence, whether the 

agency could have reached a different conclusion with regard to 

the listing of the polar bear. Rather, as mandated by the 

Supreme Court and by this Circuit, the full extent of the 

Court’s authority in this case is to determine whether the 

agency’s decision-making process and its ultimate decision to 

list the polar bear as a threatened species satisfy certain 

minimal standards of rationality based upon the evidence before 

the agency at that time. 

For the reasons set forth below, the Court is persuaded 

that the Listing Rule survives this highly deferential standard. 

After careful consideration of the numerous objections to the 

Listing Rule, the Court finds that plaintiffs have failed to 

demonstrate that the agency’s listing determination rises to the 

level of irrationality. In the Court’s opinion, plaintiffs’ 

challenges amount to nothing more than competing views about 
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policy and science. Some plaintiffs in this case believe that 

the Service went too far in protecting the polar bear; others 

contend that the Service did not go far enough. According to 

some plaintiffs, mainstream climate science shows that the polar 

bear is already irretrievably headed toward extinction 

throughout its range. According to others, climate science is 

too uncertain to support any reliable predictions about the 

future of polar bears. However, this Court is not empowered to 

choose among these competing views. Although plaintiffs have 

proposed many alternative conclusions that the agency could have 

drawn with respect to the status of the polar bear, the Court 

cannot substitute either the plaintiffs’ or its own judgment for 

that of the agency. Instead, this Court is bound to uphold the 

agency’s determination that the polar bear is a threatened 

species as long as it is reasonable, regardless of whether there 

may be other reasonable, or even more reasonable, views. That 

is particularly true where, as here, the agency is operating at 

the frontiers of science. 

In sum, having carefully considered plaintiffs’ motions, 

the federal defendants’ and defendant-intervenors’ crossmotions, the oppositions and replies thereto, various 

supplemental briefs, the supplemental explanation prepared by 

FWS in response to this Court’s November 4, 2010 remand order, 

arguments of counsel at a motions hearing held on February 23, 
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2011, the relevant law, the full administrative record, and for 

the reasons set forth below, the Court finds that the Service’s 

decision to list the polar bear as a threatened species under 

the ESA represents a reasoned exercise of the agency’s 

discretion based upon the facts and the best available science 

as of 2008 when the agency made its listing determination. 

Accordingly, the Court hereby DENIES plaintiffs’ motions for 

summary judgment and GRANTS the federal defendants’ and 

defendant-intervenors’ motions for summary judgment. 
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TABLE OF CONTENTS

INTRODUCTION

TABLE OF CONTENTS

I. BACKGROUND

A. Statutory Background

B. Factual and Procedural Background

II. STANDARD OF REVIEW

III. DISCUSSION

A. The Service Articulated a Rational Basis for Its 

Conclusion that the Polar Bear Met the Definition of a

Threatened Species at the Time of Listing

1. Plaintiff CBD’s Claim that the Polar Bear Should 

Have Been Considered Endangered at the Time of 

Listing

a. The Service’s Findings

b. Plaintiff CBD’s Arguments

c. The Court’s Analysis

i. Standard of Review on Remand

ii. Merits

2. Joint Plaintiffs’ Claim that the Polar Bear 

Should Not Have Been Considered Threatened at the 

Time of Listing

a. Joint Plaintiffs’ Argument that the Service

Failed to Demonstrate that the Polar Bear Is 

67-90% Likely to Become Endangered

b. Joint Plaintiffs’ Argument that the Service

Arbitrarily Selected 45 Years As the 

“Foreseeable Future” Timeframe for the Polar 

Bear

B. The Service Articulated a Rational Basis for Its 

Conclusion that No Polar Bear Population or Ecoregion 

Qualifies As a “Distinct Population Segment”

1. The Service’s Policy

2. Plaintiffs CBD, SCI, and CF’s Claim that the 

Service Wrongly Concluded that No Polar Bear 

Population or Ecoregion Is “Discrete”

3. The Court’s Analysis

C. The Service Did Not Arbitrarily Fail to Consider Other 

Listing Factors

1. Joint Plaintiffs’ Claim that the Service Failed 

to “Take Into Account” Foreign Conservation 

Efforts to Protect the Polar Bear

2. Joint Plaintiffs’ Claim that the Service Failed 

to Rely upon the “Best Available Science”

a. Joint Plaintiffs’ Argument that Climate 
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Science Is Too Uncertain to Support the 

Service’s Conclusion

b. Joint Plaintiffs’ Argument that the USGS 

Population Models Do Not Support the 

Service’s Conclusion 

c. Joint Plaintiffs’ Argument that the Service 

Ignored Scientific Data and Made Improper 

Findings Regarding the Southern Beaufort Sea 

Population

3. Plaintiff CBD’s Claim that the Service Failed to 

Consider Whether the Threat of Overutilization 

Warranted Listing the Polar Bear As Endangered

(“Listing Factor B”)

4. Joint Plaintiffs’ Claim that the Service Wrongly 

Concluded that Existing Regulatory Mechanisms 

Will Not Protect Polar Bears despite Anticipated 

Habitat Losses (“Listing Factor D”)

D. The Service Followed Proper Rulemaking Procedures 

1. Plaintiff Alaska’s Claim that the Service

Violated Section 4(i) of the ESA by Failing to 

Provide a Sufficient “Written Justification” in 

Response to Comments 

2. Plaintiff CF’s Claim that the Service Failed to 

Respond to Significant Comments 

IV. CONCLUSION
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I. BACKGROUND

A. Statutory Background

Congress enacted the ESA “to provide a means whereby the 

ecosystems upon which endangered species and threatened species 

depend may be conserved, [and] to provide a program for the 

conservation of such endangered species and threatened species.”2

 

16 U.S.C. § 1531(b). An “endangered species” is “any species

which is in danger of extinction throughout all or a significant 

portion of its range.” Id. § 1532(6). A “threatened species”

is “any species which is likely to become an endangered species 

within the foreseeable future throughout all or a significant 

portion of its range.” Id. § 1532(20). The term “species” is

defined in the Act to include species, subspecies, and “any 

distinct population segment of any species of vertebrate fish or 

wildlife which interbreeds when mature.” Id. § 1532(16). 

The ESA requires the Secretary of the Interior to publish 

and maintain a list of all species that have been designated as 

 2 Under the conservation program established by the ESA, a 

designation of “endangered” triggers a broad range of 

protections, including a prohibition on “taking” individual 

members of the species. See 16 U.S.C. § 1538(a)(1)(B); see also 

id. § 1532(19) (defining the term “take” to mean “harass, harm, 

pursue, hunt, shoot, wound, kill, trap, capture, or collect, or 

to attempt to engage in any such conduct”). The Act authorizes 

the Secretary to extend these prohibitions, in whole or in part, 

to threatened species as well. Id. § 1533(d). In addition, the 

Secretary shall “issue such regulations as he deems necessary 

and advisable to provide for the conservation of [threatened] 

species.” Id.
- 9 -

threatened or endangered. Id. § 1533(c). Species are added to 

and removed from this list after notice and an opportunity for 

public comment, either on the initiative of the Secretary or as 

a result of a petition submitted by an “interested person.” Id. 

§§ 1533(b)(1), (3), (5). The Secretary of the Interior and the 

Secretary of Commerce are responsible for making listing 

decisions.3 Id. §§ 1532(15), 1533(a)(2). The Secretary of the 

Interior has jurisdiction over the polar bear. See 50 C.F.R. 

§ 402.01(b). 

A listing determination is made on the basis of one or more 

of five statutorily prescribed factors: 

(a) the present or threatened destruction, 

modification, or curtailment of the species’ 

habitat or range;

(b) overutilization for commercial, recreational, 

scientific, or educational purposes;

(c) disease or predation;

(d) the inadequacy of existing regulatory mechanisms; 

or

(e) other natural or manmade factors affecting the 

species’ continued existence. 

16 U.S.C §§ 1533(a)(1)(A)-(E); see also 50 C.F.R. § 424.11(c). 

The agency must list a species if “any one or a combination” of 

these factors demonstrates that the species is threatened or 

endangered. 50 C.F.R. § 424.11(c). 

 3 The Secretary of the Interior has delegated his 

responsibilities under the Act to FWS. See 50 C.F.R. 

§ 402.01(b). The Secretary of Commerce has delegated his 

responsibilities under the Act to the National Marine Fisheries 

Service (“NMFS”). See id. 
- 10 -

The ESA further provides that the decision to list a 

species must be made

solely on the basis of the best scientific and 

commercial data available . . . after conducting a 

review of the status of the species and after taking 

into account those efforts, if any, being made by any 

State or foreign nation, or any political subdivision 

of a State or foreign nation, to protect such species

. . . . 

16 U.S.C. § 1533(b)(1)(A). 

B. Factual and Procedural Background

Polar bears are marine mammals that are described as “iceobligate,” meaning that they are evolutionarily adapted to, and 

indeed completely reliant upon, sea ice for their survival and 

primary habitat. ARL 117259.4

 They depend upon sea ice for 

critical functions such as hunting ice-dependent seals (their 

primary source of food), migrating between feeding areas and 

land-based maternity dens, and traveling long distances in 

search of mates or food. ARL 139259. Over most of their range, 

polar bears remain on the ice year-round. ARL 139245. The 

international Polar Bear Specialist Group – the authoritative 

source for information on the world’s polar bears – has 

identified nineteen polar bear populations located within five 

countries in the ice-covered regions of the Northern Hemisphere: 

 4 The facts in this background section are excerpted from the 

administrative record for the Listing Rule. Citations to the 

administrative record for the Listing Rule are abbreviated 

“ARL.” 
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the United States (in Alaska), Canada, Denmark (in Greenland), 

Norway, and Russia.5 ARL 117216-17, 117219. 

On February 16, 2005, the Center for Biological Diversity 

submitted a petition to the Secretary of the Interior to list 

the polar bear as a threatened species under the ESA due to 

observed and anticipated declines in the Arctic sea ice upon 

which the polar bear relies for survival. See generally ARL 

4040-4209. FWS ultimately issued a final rule listing the polar 

bear as a threatened species on May 15, 2008.6 See generally ARL 

 5 These nineteen populations are generally identified by 

their geographical location: Arctic Basin, Baffin Bay, Barents 

Sea, Chukchi Sea, Davis Strait, East Greenland, Foxe Basin, Gulf 

of Boothia, Kane Basin, Kara Sea, Lancaster Sound, Laptev Sea, 

M’Clintock Channel, Northern Beaufort Sea, Norwegian Bay, 

Southern Beaufort Sea, Southern Hudson Bay, Western Hudson Bay, 

and Viscount Melville Sound. ARL 117220, Figure 1. The United 

States Geological Survey (“USGS”) recently re-evaluated the 

existing population boundaries to create an additional 

population - Queen Elizabeth – located on the northern border of 

Greenland. ARL 117222. 

6 Prior to the action currently before this Court, the Center 

for Biological Diversity also initiated lawsuits to enforce 

various statutory deadlines throughout the listing process for 

the polar bear. To the maximum extent practicable, the 

Secretary must respond to listing petitions within 90 days with 

an initial finding stating whether the petition “presents 

substantial scientific or commercial information indicating that 

the petitioned action may be warranted.” 16 U.S.C. 

§ 1533(b)(3)(A). When the Secretary failed to timely respond to 

its listing petition, the Center for Biological Diversity filed 

an action in the Northern District of California in December 

2005. Ctr. for Biological Diversity v. Norton, No. 05-5191 

(N.D. Cal. filed Dec. 15, 2005). The Secretary ultimately 

published a 90-day finding on February 9, 2006, ARL 5597-98, and 

he agreed to issue the next required finding by December 27, 

2006. The parties settled the case with a consent decree to 
- 12 -

117215-117307. At the time of listing, there were estimated to 

be approximately 20,000 to 25,000 polar bears worldwide, 

distributed throughout the species’ range.7 ARL 117219. These 

estimates further indicated that two of the nineteen polar bear 

populations were increasing in numbers (Viscount Melville Sound 

and M’Clintock Channel); six populations were stable (Northern 

Beaufort Sea, Southern Hudson Bay, Davis Strait, Lancaster 

Sound, Gulf of Boothia, Foxe Basin); and five populations were

declining (Southern Beaufort Sea, Norwegian Bay, Western Hudson 

Bay, Kane Basin, Baffin Bay). ARL 117221. Insufficient data 

were available to identify trends for the remaining six 

populations (Barents Sea, Kara Sea, Laptev Sea, Chukchi Sea, 

Arctic Basin, East Greenland). ARL 117221. 

 

that effect. See Settlement Agreement, Ctr. for Biological 

Diversity v. Kempthorne, No. 05-5191 (N.D. Cal. June 28, 2006). 

On January 9, 2007, FWS published in the Federal Register a 

proposed rule to list the species as threatened throughout its 

range. See generally ARL 59985-60021. The ESA imposes a 

nondiscretionary deadline of one year from the date a proposed 

rule is published within which the agency must publish a final 

rule. 16 U.S.C. § 1533(b)(6). After that one-year deadline 

passed, the Center for Biological Diversity filed a second 

action to compel FWS to issue its final rule. Ctr. for 

Biological Diversity v. Kempthorne, No. 08-1339 (N.D. Cal. filed 

Mar. 10, 2008). The Northern District of California granted 

plaintiff’s motion for summary judgment and directed FWS to 

publish its final listing determination for the polar bear by 

May 15, 2008. Ctr. for Biological Diversity v. Kempthorne, No. 

08-1339, 2008 U.S. Dist. LEXIS 34753 (N.D. Cal. Apr. 28, 2008). 

7 The Service found that the polar bear occupied the full 

extent of its historical range at the time of listing. See ARL 

117242.

 
- 13 -

In its Listing Rule, FWS acknowledged that sea ice 

conditions across the Arctic had changed over the past several 

decades. ARL 117227-28. Specifically, the agency cited data 

indicating that the summer/fall ice melt season in the Arctic 

lengthened by approximately two weeks per decade between 1979 

and 2005. ARL 117227. The agency also cited data indicating 

that September (i.e., minimum) sea ice extent was at an all-time 

low during the period between 2002 and 2007. ARL 117224. FWS 

further noted that scientists had observed significant recent 

declines in winter (i.e., maximum) sea ice extent, ARL 117226, 

cumulative annual sea ice extent, ARL 117226, and overall sea 

ice age and thickness, ARL 117226-27. 

Relying on complex climate models and related data from the 

International Panel on Climate Change (“IPCC”) – which FWS 

acknowledged to be the leading international body in climate 

change science – FWS attributed these changes in sea ice to

increased Arctic temperatures caused by greenhouse gas emissions 

and related changes in atmospheric and oceanic circulation.8

 ARL 

117227-30. As FWS described, due to a reported lag time in 

response between when greenhouse gases are emitted into the 

 8 In its final Listing Rule, FWS relied in particular on the 

IPCC Fourth Assessment Report (“AR4”), issued in 2007, which was 

the most recent climate change report available from the IPCC at 

the time FWS made its listing determination. ARL 117231; see 

generally ARL 151180-152632. 
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atmosphere and when the impacts of those emissions are felt on 

the ground, the IPCC concluded that the global climate system is 

committed to a continued warming trend through the end of the 

21st century. ARL 117233-34. Indeed, FWS noted that average 

projected warming levels through mid-century were generally 

consistent across all IPCC climate models, regardless of 

differences in possible emission levels over that period. ARL 

117257. FWS looked also to IPCC models of Arctic sea ice, which

similarly projected declines in ice extent through the end of 

the 21st century. ARL 117234. As FWS noted, the ten models 

that most accurately reflected historical sea ice changes prior 

to 2007 all projected a decline in September sea ice extent of 

over thirty percent (30%) by mid-century. ARL 117236-37. On 

the basis of these IPCC models and associated analysis, FWS 

concluded that it could confidently predict a significant 

decline in the polar bear’s sea ice habitat over the next 40 to 

50 years. ARL 117279-81. 

FWS further concluded that the extent of anticipated 

declines in sea ice will significantly impact polar bear 

population health. ARL 117279. As FWS described, sea ice

losses have been tied to nutritional stress in polar bears 

because of lower overall numbers of ice-dependent prey, 

decreased access to the prey that remain, shorter hunting 

seasons and longer seasonal fasting periods, and higher 
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energetic demands from traveling farther and swimming longer 

distances across open water to reach sea ice. ARL 117279. FWS 

determined that this nutritional stress and other related 

factors will likely result in a decline in the physical 

condition of polar bears, leading to lower overall body weights

and reduced cub survival rates. ARL 117270. FWS further found 

that consistent declines in physical condition and reproductive 

success will ultimately lead to population-level declines. ARL 

117279. 

In reaching this conclusion, FWS relied in part on longterm studies showing that these impacts had already been 

observed in some of the southern-most polar bear populations. 

According to FWS, monitoring reports indicated that the Western 

Hudson Bay population – one of the longest-studied polar bear 

groups – had experienced declines in body condition among both 

adult male and adult female bears over the past three decades, 

with an associated population decrease of approximately twentytwo percent (22%). ARL 117271. FWS noted that this Canadian 

population also experienced significant declines in body mass 

among female bears over that period. ARL 117270. A 

comprehensive review of the polar bear’s status conducted prior 

to listing indicated that, between 1971 and 2001, the average 

date of spring break-up of the sea ice in the region advanced by 

three weeks, and temperatures increased by between 0.5oC and 
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0.8oC per decade. ARL 139286. The correlation between the 

timing of sea ice break-up and the body condition of adult 

female polar bears was found to be statistically significant. 

ARL 139286. 

The same polar bear status review also indicated that 

scientists monitoring the Southern Beaufort Sea polar bear 

population – another long-studied group – observed similar

changes in body condition and unusual hunting behaviors. ARL 

139279. As noted in the status review, population estimates for 

this group between 1986 and 2006 also showed declines, although 

researchers were not confident enough in these estimates to 

assert that the observed declines were statistically 

significant. ARL 139279. 

Prior to issuing its final rule, FWS commissioned the 

United States Geological Survey (“USGS”) to conduct additional 

scientific analysis related to the polar bear listing decision.9

 

Among other things, USGS undertook an effort to forecast the 

status of polar bears in different parts of the Arctic at three 

future time periods in the 21st century (i.e., 45 years, 75 

years, and 100 years). See generally Forecasting the Range-Wide 

 9 FWS commissioned USGS to prepare this additional analysis 

in February 2007, after the publication of the proposed listing 

rule to list the polar bear as a threatened species. ARL 

117239. In response to the significant new information 

contained in the USGS reports, FWS re-opened the public comment 

period on the proposed rule through October 22, 2007. ARL 

117239. 
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Status of Polar Bears at Selected Times in the 21st Century, ARL

161306-161436. USGS developed two models in an effort to 

predict potential future changes to polar bear population

numbers across a range of scenarios, using climate models and 

the existing body of knowledge about polar bears. ARL 161313. 

A simple “carrying capacity” model was designed to estimate 

potential changes in numbers of bears based on current polar 

bear population densities and annual sea ice projections. ARL 

161316. A more comprehensive “Bayesian Network” model was

designed to determine the probability of certain population 

outcomes (e.g., “larger than now,” “same as now,” “smaller,”

“rare,” or “extinct”), taking into account a wide range of 

factors including the seasonal availability of sea ice, as well 

as population stressors unrelated to sea ice loss. ARL 161317, 

161325-26. 

For the purpose of these models, USGS grouped the nineteen 

global polar bear populations into four “ecoregions” – Seasonal 

Ice, Divergent Ice, Convergent Ice, and Archipelago – based upon 

regional patterns of ice formation. ARL 117276. The Seasonal 

Ice Ecoregion, for example, occurs at the southern end of the 

polar bear range and is ice-free for a portion of the year. ARL 

117221. In the Divergent Ice Ecoregion, which is located mainly 

in Alaska, ice formed at the shore drifts away from land as a 

result of wind and ocean currents. ARL 117222. In the 
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Convergent Ice Ecoregion, sea ice formed in the Divergent Ice 

Ecoregion moves toward land and collects at the shore. ARL 

117222. The Archipelago Ecoregion, at the northernmost point of 

the Canadian Arctic, generally has thicker and more persistent 

ice year-round. ARL 117222. USGS determined that these 

variations in sea ice conditions generally correlate to 

differences in how polar bears interact with their sea ice

habitat. ARL 117221.

Consistent with IPCC climate and sea ice models, both of 

the USGS models projected population declines in all four polar 

bear ecoregions over the next 100 years. ARL 161312. The 

simple carrying capacity model indicated that polar bear 

population levels range-wide will have moderately decreased by 

year 45, assuming average projected levels of future sea ice. 

ARL 161331. Assuming minimal levels of future sea ice, the 

carrying capacity model projected trends “toward extirpation” of 

bears in the Divergent Ice Ecoregion by year 45 and in the 

Seasonal Ecoregion by year 75. ARL 161331. Similarly, 

according to USGS, the Bayesian Network model results suggested

that “multiple stressors will likely play important and 

deleterious roles on all polar bear populations, even starting 

at year 45, and generally increase in their effect through year 

100.” ARL 161332. For example, the Bayesian Network model 

projected an outcome of extinction for bears in the Seasonal and 
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Divergent Ice Ecoregions by year 45 and for bears in the 

Convergent Ice Ecoregion by year 75. ARL 161312-13. In the 

Archipelago Ecoregion, a “smaller” population was the dominant 

outcome at year 45 under all scenarios. ARL 161332. 

In relying on the USGS population models, FWS emphasized

that it had less confidence in the specific numerical outcomes 

of these models than in their “general direction and magnitude.” 

ARL 117278. Specifically, FWS pointed to several caveats that 

USGS itself identified in the development of these models. As 

FWS described, USGS acknowledged that the carrying capacity 

model only accounted for changes in sea ice extent and could not

account for several other important factors, including seasonal 

ice fluctuations and other population stressors. ARL 117277. 

Further, USGS indicated that this simple model assumed a linear 

relationship between sea ice and numbers of bears, which is not 

necessarily the case, and it also assumed that polar bear 

density will not change over time, which “is almost certainly 

not valid.” ARL 161323. FWS similarly discounted the specific 

outcomes of the Bayesian Network model, which USGS described as 

a “first-generation ‘alpha’ level prototype,” ARL 161338, 

because it reflected the judgment of only one polar bear expert 

and “still must be vetted through other polar bear experts.” 

ARL 161338; see also ARL 117278. Insofar as these population 

models were generally consistent with the record as a whole, 
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however, FWS found that these models supported a conclusion that 

sea ice losses will negatively impact polar bears in a 

significant way within the foreseeable future. ARL 117278; ARL 

117300. 

Based on a voluminous administrative record, including the 

studies described above, and input from fourteen peer reviewers 

and numerous polar bear specialists, climate scientists, experts 

in Traditional Ecological Knowledge (“TEK”),10 state and federal 

agencies, foreign governments, Alaska Native tribes and tribal 

organizations, federal commissions, local governments, 

commercial and trade organizations, conservation organizations, 

nongovernmental organizations, and private citizens, FWS 

concluded that the polar bear was threatened throughout its 

range at the time of listing, within the meaning of the ESA. 

ARL 117296. Specifically, FWS determined that all polar bear 

 10 TEK is a formally-recognized body of knowledge developed by 

the native people who co-exist with the polar bear in its 

habitat. TEK principles and observations include where and when 

polar bears feed, how they hunt, where they den, how they 

respond to different types of ice habitat, and how they travel. 

See Defendant-Intervenor Arctic Slope Regional Corporation 

Cross-Motion and Memorandum in Opposition, Docket Nos. 146, 147 

(“ASRC Def-Int. Mot.”) at 3. This knowledge has been gained 

through traditional subsistence efforts, handed down over 

generations by oral tradition, and shared with scientists 

researching the species, including FWS scientists. ASRC DefInt. Mot. at 3. TEK offers an opportunity for “clear 

observational records over relatively long temporal scales.”

ASRC Def-Int. Mot. at 11 (quoting ARL 130884). For the purposes 

of the Listing Rule, FWS accepted TEK as a relevant source of 

information on the ecology of polar bears. ARL 117252. 
- 21 -

populations will be affected by substantial losses of sea ice 

within the foreseeable future (which it defined as 45 years), 

although different populations will be affected at different 

rates and to different degrees. ARL 117279-80. FWS further 

found that polar bears are unlikely to adapt to these 

anticipated habitat changes. ARL 117264-66. 

However, notwithstanding these findings, FWS concluded that 

the polar bear was not endangered in any portion of its range at

the time of listing. ARL 117301. The agency determined that at 

the time of listing the species was generally abundant 

throughout its range, the species continued to occupy the full 

extent of its historical range, and it had yet to experience 

precipitous population declines in any portion of its range. 

ARL 117299-301. Even in the Western Hudson Bay population, 

where a statistically-significant decline had been observed, the 

species continued to reproduce normally. ARL 117300. According 

to FWS, these countervailing facts demonstrated that the polar 

bear was not “in danger of extinction” at the time it made its 

listing decision, although the agency reiterated that the 

species would likely become an endangered species by midcentury. ARL 117301. 

The publication of the Listing Rule triggered lawsuits by a 

number of organizations and individuals: (1) the State of Alaska 
- 22 -

(“Alaska”)11 (State of Alaska v. Salazar, et al., No. 08-1352

(D.D.C. Aug. 4, 2008)); (2) Safari Club International and Safari 

Club International Foundation (collectively, “SCI”)12 (Safari 

Club Int’l, et al. v. Salazar, et al., No. 08-1550 (D.D.C. Sept. 

8, 2008)); (3) California Cattlemen’s Association and the 

Congress on Racial Equality (collectively, “CCA”)13 (California 

Cattlemen’s Ass’n, et al. v. Salazar, et al., No. 08-1689

(D.D.C. Oct. 2, 2008)); (4) Center for Biological Diversity, 

Natural Resources Defense Council, and Greenpeace (collectively, 

“CBD”)14 (Ctr. for Biological Diversity, et al. v. Salazar, et 

 11 The State of Alaska is a sovereign state with an averred 

interest in the management of its wildlife and natural 

resources, including the polar bear, and an averred interest in 

the impact of the Listing Rule on public services, tourism, 

transportation, and resource development within the state. 

Alaska Compl. ¶¶ 9, 10.

12 Safari Club International and Safari Club International 

Foundation are not-for-profit public education and hunting 

advocacy organizations with an averred interest in the impact of 

the Listing Rule on sustainable use wildlife conservation 

efforts, including foreign trophy hunting programs. SCI Compl. 

¶¶ 14-17.

13 California Cattlemen’s Association and the Congress on 

Racial Equality are not-for-profit organizations that represent 

California’s beef producers and poor and minority business 

owners, respectively, with an averred interest in ensuring that 

the Listing Rule does not expose their members to an elevated 

risk of citizen suits and increased costs of doing business. 

CCA First Am. Compl. ¶¶ 5, 6. 

14 Center for Biological Diversity, Natural Resources Defense 

Council, and Greenpeace are not-for-profit environmental 

advocacy organizations with members that have an averred 

interest in the protection and conservation of wildlife species, 
- 23 -

al., No. 08-1339 (N.D. Cal. Mar. 10, 2008));15 and 

(5) Conservation Force, the Inuvialuit Game Council, and 

numerous hunting and trapping organizations as well as 

individuals (collectively, “CF”)16 (Conservation Force, et al. v. 

Salazar, et al., No. 09-245 (D.D.C. Feb. 9, 2009)). These five 

actions were subsequently consolidated before this Court, along 

with six related actions, pursuant to an order of the Judicial 

Panel on Multi-District Litigation.17 See generally Certified 

Copy of Transfer Order, Docket No. 1.18 

 

such as the polar bear, and their habitat. CBD Third Am. Compl. 

¶¶ 20-23.

15 This case was subsequently transferred and assigned a new 

case number in this Court. See Ctr. for Biological Diversity, 

et al. v. Salazar, et al., No. 08-2113 (D.D.C. Dec. 8, 2008). 

16 Conservation Force is a not-for-profit wildlife 

conservation organization with an averred interest in managing 

and protecting game species, including polar bears. CF Compl. 

¶ 16. Joining with Conservation Force in its lawsuit is the 

Inuvialuit Game Council, which represents the interests of the 

Inuvialuit people on all matters pertaining to wildlife 

management within Canada’s Inuvialuit Settlement Region. CF 

Compl. ¶ 17. Also joining with these plaintiffs are a number of 

hunting and trapping organizations, sportsmen organizations and 

outfitters, and individuals who have participated in polar bear 

trophy hunting. CF Compl. ¶¶ 18-50. 

17 On the same day that FWS issued its final rule listing the 

polar bear as a threatened species, the Secretary of the 

Interior published proposed regulations pursuant to 16 U.S.C. 

§ 1533(d). See Special Rule for the Polar Bear, 73 Fed. Reg. 

28,306 (May 15, 2008) (“Interim 4(d) Rule”). These regulations 

were later finalized and codified at 50 C.F.R. § 17.40(q) and 

are the subject of two additional actions before this Court. 

The four remaining actions challenge the Service’s subsequent 

refusal to issue permits for importing sport-hunted polar bear 
- 24 -

Several groups intervened to defend against plaintiffs’ 

challenges to the Listing Rule. Specifically, this Court 

permitted the Alaska Oil and Gas Association (“AOGA”) and the 

Arctic Slope Regional Corporation (“ASRC”) to intervene as 

defendants in the challenge brought by plaintiff CBD. See 

Stipulation and Order Regarding Intervention, Docket No. 33, at 

4-5. The Court also permitted SCI, a plaintiff in its own 

action, to intervene as a defendant in the action brought by 

plaintiff CBD. Plaintiff CBD was permitted to intervene as a 

defendant in the remaining challenges to the Listing Rule. 

On October 20, 2009, plaintiffs filed their motions for 

summary judgment.19 Among other claims, plaintiff CBD contends 

 

trophies under the Marine Mammal Protection Act (“MMPA”), 16 

U.S.C. §§ 1371-1389 (2006). These six actions have been briefed 

separately from the Listing Rule cases; therefore, the Court 

does not address either the 4(d) Rule or the import ban 

challenges here. 

18 Unless otherwise specified, all references to pleadings, 

proceedings, hearings, opinions, and orders can be found on the 

Misc No. 08-764 docket. 

19 Plaintiffs Center for Biological Diversity, Natural 

Resources Defense Council and Greenpeace jointly filed a motion 

for summary judgment. See generally Motion for Summary Judgment 

by CBD, Docket No. 125 (“CBD Mot.”). The remaining plaintiffs 

also filed a joint motion for summary judgment that addresses 

their common claims. See generally Joint Motion for Summary 

Judgment on Listing Rule Claims, Docket No. 127 (“JP Mot.”). 

The Court also permitted each of these plaintiffs to submit 

supplemental motions and memoranda in support of summary 

judgment. See generally Alaska’s Motion for Summary Judgment on 

Listing Rule Claims, Docket No. 128 (“Alaska Mot.”); Motion and 

Supplemental Memorandum of CCA in Support of Motion for Summary 
- 25 -

that the decision to list the polar bear as threatened was 

arbitrary and capricious because the polar bear met the 

definition of an endangered species under the ESA at the time of 

listing and thus qualified for a higher level of protection. 

The remaining plaintiffs (collectively, “Joint Plaintiffs”) 

contend, among other things, that the decision to list the polar 

bear was arbitrary and capricious because the polar bear did not 

meet the definition of a threatened species at the time of 

listing and therefore did not qualify for ESA protections.

The federal defendants filed their cross-motion for summary 

judgment on December 7, 2009. See generally Federal Defendants’ 

Combined Opposition and Cross-Motion for Summary Judgment on 

Listing Rule Claims, Docket No. 137 (“Fed. Def. Mot.”). The 

various defendant-intervenors filed their cross-motions for 

summary judgment on January 19, 2010.20

 

Judgment Challenging the Listing Rule, Docket No. 124 (“CCA 

Mot.”); Motion for Summary Judgment and Supplemental Memorandum 

of Points and Authorities by SCI, Docket No. 123 (“SCI Mot.”); 

Motion for Summary Judgment by CF, Docket No. 126, corrected at 

Docket No. 131 (“CF Mot.”).

20 See generally Defendant-Intervenor SCI Cross-Motion for 

Summary Judgment and Memorandum in Opposition, Docket Nos. 144, 

145 (“SCI Def-Int. Mot.”); Defendant-Intervenor ASRC CrossMotion and Memorandum in Opposition, Docket Nos. 146, 147 (“ASRC 

Def-Int. Mot.”); Defendant-Intervenor AOGA Cross-Motion for 

Summary Judgment, Docket No. 148 (“AOGA Def-Int. Mot.”); 

Defendant-Intervenor CBD Cross-Motion for Summary Judgment, 

Docket No. 149 (“CBD Def-Int. Mot.”). 
- 26 -

This Court held an initial hearing on the parties’ crossmotions for summary judgment on October 20, 2010. At that 

hearing, the Court focused only on a threshold question: whether 

it must review the agency’s interpretation of the ESA listing 

classifications under step one or step two of the familiar

framework set forth in Chevron, U.S.A., Inc. v. Natural 

Resources Defense Council, Inc., 467 U.S. 837 (1984). In a 

Memorandum Opinion issued on November 4, 2010, the Court held 

that FWS had improperly relied on an erroneous plain-meaning 

reading of the definition of an endangered species that could 

not be upheld under step one of Chevron. In re Polar Bear 

Endangered Species Act Listing and § 4(d) Rule Litigation, 748 

F. Supp. 2d 19, 29 (D.D.C. 2010) [hereinafter In re Polar Bear]. 

Finding that the term “endangered species” under the ESA is 

instead ambiguous, the Court remanded the Listing Rule to the 

agency “to treat the statutory language as ambiguous.” Id.

In response to the Court’s remand order, on December 22, 

2010, the federal defendants submitted the agency’s memorandum 

of supplemental explanation. See generally Supplemental 

Explanation for the Legal Basis of the Department’s May 15, 2008 

Determination of Threatened Status for Polar Bears, Docket No. 

237-1 (“Supp. Exp.”). In their Supplemental Explanation, FWS 

concluded that, even treating the phrase “in danger of 

extinction” in the definition of an endangered species as 
- 27 -

ambiguous, the administrative record does not support a finding 

that the polar bear qualified for endangered status at the time 

of listing. Because the agency determined that the species is

likely to become endangered within the foreseeable future, 

however, FWS reiterated that the polar bear met ESA’s the 

definition of a threatened species at the time of listing. 

Supp. Exp. at 16. 

The Court gave the parties an opportunity to submit 

additional briefs responding to the agency’s supplemental 

explanation. See generally Joint Plaintiffs’ Response to 

Federal Defendants’ Supplemental Explanation, Docket No. 240

(“JP Supp. Mem.”); Plaintiff CBD’s Response to Federal 

Defendants’ Supplemental Explanation, Docket No. 241 (“CBD Supp. 

Mem.”); AOGA and ASRC Defendant-Intervenors’ Response to Federal 

Defendants’ Supplemental Explanation, Docket No. 239 (“AOGA 

Supp. Mem.”); Federal Defendants’ Supplemental Reply, Docket No. 

242 (“Fed. Def. Supp. Reply”). A second motions hearing was 

held on February 23, 2011, during which the Court heard 

arguments on all plaintiffs’ Listing Rule claims. The parties’ 

cross-motions for summary judgment are now ripe for 

determination by the Court. 

II. STANDARD OF REVIEW

The Service’s listing decisions are subject to review under 

the APA. See, e.g., Am. Wildlands v. Kempthorne, 530 F.3d 991, 
- 28 -

997 (D.C. Cir. 2008). Under APA review, federal agency actions 

are to be held unlawful and set aside where they are “arbitrary, 

capricious, an abuse of discretion, or otherwise not in 

accordance with law.” 5 U.S.C. § 706(2)(A). To make this 

finding, a court must determine whether the agency “considered 

the factors relevant to its decision and articulated a rational 

connection between the facts found and the choice made.” 

Keating v. FERC, 569 F.3d 427, 433 (D.C. Cir. 2009) (citing 

Balt. Gas & Elec. Co. v. Natural Res. Def. Council, Inc., 462 

U.S. 87, 105 (1983)). 

The standard of review under the APA is a narrow one. 

Citizens to Pres. Overton Park v. Volpe, 401 U.S. 402, 416 

(1971). The court is not empowered to substitute its judgment 

for that of the agency. Id. Deference to the agency’s judgment 

is particularly appropriate where the decision at issue 

“requires a high level of technical expertise.” Marsh v. Or. 

Natural Res. Council, 490 U.S. 360, 375-77 (1989); Ethyl Corp. 

v. EPA, 541 F.2d 1, 36 (D.C. Cir. 1976) (“[The court] must look 

at the decision not as the chemist, biologist or statistician 

that [it is] qualified neither by training nor experience to be, 

but as a reviewing court exercising [its] narrowly defined duty 

of holding agencies to certain minimal standards of 

rationality.”). Specifically, with regard to FWS decisions, 

this Court has previously recognized that “[g]iven the expertise 
- 29 -

of the FWS in the area of wildlife conservation and management 

and the deferential standard of review, the Court begins with a 

strong presumption in favor of upholding decisions of the 

[FWS].” Am. Wildlands v. Kempthorne, 478 F. Supp. 2d 92, 96 

(D.D.C. 2007) (citing Carlton v. Babbitt, 900 F. Supp. 526, 530 

(D.D.C. 1995)). 

This narrow, deferential standard does not, however, shield 

the agency from a “thorough, probing, in-depth” review. Overton 

Park, 401 U.S. at 415. The court’s inquiry into the facts must 

be both “searching and careful.” Id. at 416. Administrative 

action must be invalidated as arbitrary where the agency

relied on factors which Congress has not intended it 

to consider, entirely failed to consider an important 

aspect of the problem, offered an explanation for its 

decision that runs counter to the evidence before the 

agency, or is so implausible that it could not be 

ascribed to a difference in view or the product of 

agency expertise. 

Motor Vehicle Mfrs. Ass’n v. State Farm Mut. Auto Ins. Co., 463 

U.S. 29, 43 (1983). This determination must be made solely on 

the basis of the record before the agency when it made its 

decision. Camp v. Pitts, 411 U.S. 138, 142 (1973). 

Where the court reviews an agency’s interpretation of a 

statute it is charged with administering, the Supreme Court’s 

opinion in Chevron provides the appropriate framework of review. 

The first step in this review process is for the court to 

determine “whether Congress has directly spoken to the precise 
- 30 -

question at issue.” Chevron, 467 U.S. at 842. “If the intent 

of Congress is clear, that is the end of the matter; for the 

court, as well as the agency, must give effect to the 

unambiguously expressed intent of Congress.” Id. at 842-43. In 

determining whether the statute unambiguously expresses the 

intent of Congress, the court should use all the “traditional 

tools of statutory construction,” see id. at 843 n.9, including 

looking to the text and structure of the statute, as well as its 

legislative history, if appropriate. See Bell Atlantic Tel. Co. 

v. FCC, 131 F.3d 1044, 1047 (D.C. Cir. 1997). 

If the court concludes that the statute is either silent or 

ambiguous with respect to the precise question at issue, the 

second step of the court’s review process is to determine 

whether the interpretation proffered by the agency is “based on 

a permissible construction of the statute.” Chevron, 467 U.S. 

at 843. The court must defer to agency interpretations that are 

not “procedurally defective, arbitrary or capricious in 

substance, or manifestly contrary to the statute.” United 

States v. Mead, 533 U.S. 218, 227 (2001) (citing Chevron, 467 

U.S. at 843-44). 

III. DISCUSSION

Plaintiffs have identified a number of purported 

deficiencies in the Listing Rule, each of which forms the basis 

for a claim that FWS violated both the ESA and the APA when it 
- 31 -

listed the polar bear as a threatened species. Plaintiffs’ 

claims can be classified into three general categories. 

First, each of the plaintiffs in this case argues that the 

Service’s decision to list the polar bear as a threatened 

species was based on a fundamentally flawed interpretation of 

the ESA’s listing standards and a misguided application of the 

record evidence. Specifically, plaintiff CBD claims that FWS 

wrongly concluded that the polar bear did not qualify for 

endangered status at the time of listing, given the evidence in 

the record indicating that substantial anticipated sea ice 

losses will continue through the end of the 21st century. By 

contrast, Joint Plaintiffs claim that FWS failed to demonstrate 

that the polar bear is sufficiently likely to become endangered 

within the foreseeable future and, therefore, the agency wrongly 

concluded that the polar bear qualified for threatened status at 

the time of listing. In the alternative, a smaller subset of 

plaintiffs (including CBD, SCI, and CF) argues that FWS erred 

when it concluded that no polar bear population or ecoregion

qualifies as a “distinct population segment,” which would have 

allowed the Service to tailor ESA protections more narrowly 

across populations. 

Second, plaintiffs argue that FWS ignored or otherwise 

failed to adequately address four listing factors that the ESA 

requires the agency to consider. Joint Plaintiffs claim that 
- 32 -

the Service failed to adequately “take into account” foreign 

conservation programs, particularly Canadian sport-hunting 

programs, because it failed to ensure that its listing decision 

would not negatively impact those programs. Joint Plaintiffs 

also claim that the Service failed to demonstrate that it relied 

upon the “best available science,” because the climate models, 

population models, and population monitoring studies the Service 

relied upon do not, in fact, support the agency’s conclusion 

that the polar bear is likely to become endangered within the 

foreseeable future. Plaintiff CBD claims that FWS improperly 

downplayed the threat of hunting to the polar bear and wrongly 

concluded that the polar bear was not in danger of extinction at 

the time of listing as a result of the combined threats of 

habitat loss (“Listing Factor A”) and overutilization (“Listing

Factor B”). Joint Plaintiffs finally claim that FWS wrongly 

concluded that existing regulatory mechanisms (“Listing Factor 

D”) will be insufficient to protect the polar bear despite 

future sea ice losses. 

Third and finally, plaintiffs identify deficiencies in the 

Service’s decision-making process for the Listing Rule. 

Plaintiff Alaska claims that FWS failed to provide an adequate 

“written justification” in response to the State’s comments, as 

it was required to do under Section 4(i) of the ESA. Plaintiff 
- 33 -

CF claims that FWS similarly erred by failing to respond to its 

comments on the Listing Rule. 

Having carefully considered each of these arguments, the 

Court is simply not persuaded that the Service’s decision to 

list the polar bear as a threatened species under the ESA was 

arbitrary and capricious. As the Supreme Court noted in Babbitt 

v. Sweet Home, “[t]he task of defining and listing endangered 

and threatened species requires an expertise and attention to 

detail that exceeds the normal province of Congress,” and of the 

courts as well. 515 U.S. 687, 708 (1995). This Court is not 

empowered to substitute its own judgment for that of the agency 

but can only hold the agency to “minimal standards of 

rationality.” Ethyl Corp., 541 F.2d at 36. Accordingly, and 

for the reasons set forth below, the Court finds that the

Listing Rule represents a reasoned exercise of the Service’s 

discretion based on the facts and the best available science at 

the time the agency made its determination.

The Court will now address each of plaintiffs’ claims in 

turn.21

 21 As a threshold matter, the federal defendants contend that 

one set of plaintiffs – California Cattlemen’s Association and 

the Congress on Racial Equality – failed to demonstrate standing 

to challenge the Listing Rule and, therefore, any claims 

uniquely raised by those plaintiffs must be dismissed. The 

Court finds, however, that these plaintiffs have raised no 

claims that were not also fully briefed by the larger group of 

Joint Plaintiffs. Accordingly, as the federal defendants 
- 34 -

A. The Service Articulated a Rational Basis for Its 

Conclusion that the Polar Bear Met the Definition of a

Threatened Species at the Time of Listing

1. Plaintiff CBD’s Claim that the Polar Bear Should 

Have Been Considered Endangered at the Time of 

Listing

The Court turns first to plaintiff CBD’s claim that FWS 

wrongly concluded that the polar bear did not qualify for 

endangered status as of 2008. The Court will begin by outlining 

the Service’s interpretation of the definition of an endangered 

species under the ESA, as applied to the polar bear. 

a. The Service’s Findings

In their original briefs and at a motions hearing held on 

October 20, 2010, the federal defendants argued that the text, 

structure, and legislative history of the ESA plainly and 

unambiguously require that a species must be in imminent danger 

of extinction to be designated as an endangered species. This 

Court held in a November 4, 2010 Memorandum Opinion that neither 

 

concede that the remaining plaintiffs in this action have 

demonstrated their standing to challenge the Listing Rule, see 

Fed. Def. Reply, Docket No. 195, at 71-72, the Court need not 

consider the federal defendants’ standing challenge, and it 

declines to do so. See Massachusetts v. EPA, 549 U.S. 497, 518 

(2007) (“Only one of the petitioners needs to have standing to 

permit us to consider the petition for review.”); see also Ass’n

of Am. Physicians and Surgeons, Inc. v. FDA, 539 F. Supp. 2d 4, 

14 (D.C. Cir. 2008) (citing Mountain States Legal Found. v. 

Glickman, 92 F.3d 1228, 1232 (D.C. Cir. 1996) (“‘For each claim, 

if constitutional and prudential standing can be shown for at 

least one plaintiff, [the court] need not consider the standing 

of the other plaintiffs to raise that claim.’”)).
- 35 -

the statute itself nor its legislative history compels the 

federal defendants’ reading of the term “in danger of 

extinction” and that the term is, instead, ambiguous. In re 

Polar Bear, 748 F. Supp. 2d at 28-29. Accordingly, following 

D.C. Circuit precedent, the Court remanded the rule to agency 

decision-makers to “fill in the gap” in the statute by providing 

additional explanation for the agency’s determination that the 

polar bear was not in danger of extinction at the time of 

listing. Id. at 29. On December 22, 2010, the federal 

defendants submitted the agency’s Supplemental Explanation in 

response to the Court’s remand order. 

The Service emphasizes that its Supplemental Explanation is

not intended to set forth a new statement of agency policy or a 

new “rule” pursuant to the APA, nor does the agency intend to 

adopt independent, broad-based criteria for defining the 

statutory term “in danger of extinction.” Supp. Exp. at 1-2. 

Nonetheless, the agency claims that its starting point in making 

such a determination is the general understanding that the 

phrase “in danger of extinction” describes a species that is 

currently on the brink of extinction in the wild. Supp. Exp. at 

3. According to FWS, to be “currently on the brink of 

extinction” does not necessarily mean that extinction is certain 

or inevitable; rather, whether a species is currently on the 

brink of extinction “depends on the life history and ecology of 
- 36 -

the species, the nature of the threats, and the species’ 

response to those threats.” Supp. Exp. at 3. 

As FWS describes, the agency’s past “endangered” listings 

can be broken out into roughly four categories: 

Category 1: Species facing a catastrophic threat from 

which the risk of extinction is imminent and certain.

In this category, the timing of the threat alone is 

sufficient to deem the species in danger of 

extinction. The snail darter is the classic example 

of a species in this category. See Tenn. Valley Auth.

v. Hill, 427 U.S. 153 (1978). This fish species was 

discovered shortly after the Tennessee Valley 

Authority had begun construction of the Tellico Dam on 

the Little Tennessee River and, at the time of 

listing, the dam project threatened to immediately and 

completely obliterate the only known population. 

Category 2: Narrowly restricted endemics that, as a 

result of their limited range or population size, are 

vulnerable to extinction from elevated threats. This 

category applies to species found in an extremely 

limited range that, in addition, are facing increasing 

threats. A large portion of listed species fall in 

this category. An example of one of these species is 

the Devil’s Hole pupfish, which lives in a single 

sinkhole in the southern Nevada desert that is 

experiencing a drop in groundwater level. See 

Cappaert v. United States, 426 U.S. 128 (1976). 

Category 3: Species formerly more widespread that have 

been reduced to critically low numbers or restricted 

ranges and, consequently, are at a high risk of 

extinction due to threats that would not otherwise 

imperil the species. This category represents a class 

of species experiencing both a severe range reduction 

and/or precipitous population crash combined with 

ongoing threats. Some examples of species falling in 

this category include California condors, whooping 

cranes, and vernal pool species, many of which have 

been all but wiped out by development and related 

factors. These species experience such a restricted 

range that they are extremely vulnerable to both 

ongoing and chance threats. 
- 37 -

Category 4: Species with relatively widespread 

distribution that have nevertheless suffered ongoing 

major reductions in numbers, range, or both, as a 

result of persistent threats. This category shares 

common characteristics with threatened species in that 

they have suffered some recent decline in numbers, 

range, or both, but to a more severe extent. An 

example of a species falling in this category is the 

red-cockaded woodpecker, which was formerly a common 

bird but experienced a precipitous decline in 1970 

caused by an almost complete loss of its primary 

longleaf pine habitat. Currently, only small, 

isolated populations of this species remain, making 

the species more vulnerable to threats including 

reproductive isolation. 

Supp. Exp. at 4-6. Although there is no single metric for 

determining if a species is “in danger of extinction,” FWS

contends that these four categories demonstrate the agency’s

largely consistent approach to endangered species listings. See 

Supp. Exp. at 4. 

The Service asserts that its general understanding of the 

statutory definition of an “endangered species” and its approach 

to species listings is supported by the text, structure, and the 

legislative history of the ESA. The Service notes that, insofar 

as an endangered species is any species which “is in danger of 

extinction” and a threatened species is any species which is 

“likely to become an endangered species within the foreseeable 

future,” the ESA recognizes species with “two distinct degrees 

of imperilment based on the temporal proximity of the risk of 

extinction.” Supp. Exp. at 9. Within that general framework, 
- 38 -

the agency must exercise its discretion and expert judgment to 

weigh multiple factors on a species-specific basis. The Service

asserts that its past listing decisions, including the polar 

bear Listing Rule, represent a reasoned exercise of that 

discretion.22

The Service contends that its species-specific listing 

determination for the polar bear constitutes a permissible 

construction of the ESA, given the life history and ecology of 

the species, the nature and timing of the threats, and the 

species’ observed and anticipated responses to those threats. 

According to FWS, the administrative record in this case 

demonstrates that, at the time of listing, the polar bear fit 

none of the four general categories of endangered species 

identified by the agency as representative of its past listing 

decisions. Rather, the evidence before the agency showed that 

at the time of listing the polar bear was a widespread, 

circumpolar species that had not been restricted to a critically 

 22 As this Court observed in its November 4, 2010 opinion, the 

courts have not offered an interpretation of the phrase “in 

danger of extinction” in the context of reviewing a listing 

determination. In re Polar Bear, 748 F. Supp. 2d at 26 n.12. 

Nonetheless, FWS asserts that its approach is consistent with 

judicial interpretations indicating that Congress intended to 

delegate broad responsibility to the agency to make listing 

determinations. See, e.g., Trout Unlimited v. Lohn, 559 F.3d 

946, 961 (9th Cir. 2009) (in which the court found that “[b]y 

leaving an ‘explicit gap’ for agency-promulgated regulations, 

the ESA expressly delegates authority to the [agency] to decide 

how such listing determination should be made.”). 
- 39 -

small range or critically low numbers, nor had it suffered 

precipitous reductions in numbers or range. See Supp. Exp. at 

15. 

Specifically, FWS found the following facts dispositive: 

• At the time of listing, the polar bear was widely 

distributed in nineteen populations and numbered in 

abundance between 20,000 to 25,000 individuals. Supp. 

Exp. at 15. 

• Fourteen of the nineteen polar bear populations were

considered to be stable, increasing, or data deficient at 

the time of listing. Supp. Exp. at 15. 

• Only one population - Western Hudson Bay - was verified 

to be in a statistically-significant decline, although 

two other populations were also actually or potentially 

declining. Supp. Exp. at 15. 

• No population decline was found to be precipitous, and 

reproduction and recruitment were still occurring in 

declining populations. Supp. Exp. at 15. 

In short, FWS determined, “there is simply no information 

in the Administrative Record to suggest that the species has

experienced significant population declines or severe 

retractions in its range such that it is currently on the brink 

of extinction or that it faced a sudden and calamitous threat.” 

Supp. Exp. at 15-16.23 Accordingly, the agency concluded that 

 23 Although population modeling for the species projected 

significant future declines in some polar bear populations, the 

agency ultimately determined that these model outcomes were too 

uncertain to support a specific conclusion about the actual rate 

of decline. See Supp. Exp. at 17. Similarly, although 

population monitoring showed evidence of significant declines in 

body condition in some polar bear populations, see Supp. Exp. at
- 40 -

the polar bear warranted listing as threatened range-wide but 

did not qualify as an endangered species at the time of listing. 

b. Plaintiff CBD’s Arguments

Plaintiff CBD contends that, despite this Court’s remand 

order, the agency’s interpretation of the term “endangered 

species” to exclude the polar bear continues to violate the ESA. 

First, CBD contends that the agency has not significantly 

departed from its original position that an endangered species 

must be at risk of both imminent and certain extinction. 

According to CBD, nothing in the text, structure, or legislative 

history of the ESA supports the Service’s conclusion that the 

temporal proximity of an extinction threat is the controlling 

distinction between a threatened and an endangered species.24 

Such a narrow reading of the statute, CBD contends, sets the bar 

for an “endangered” listing impossibly high. Moreover, it 

contravenes the purpose of the ESA, which is to provide a 

flexible approach to protecting species so that they can be 

recovered and delisted. 

 

17, FWS found them insufficient to warrant endangered status for 

any particular population at the time of listing. See Supp. 

Exp. at 18. 

24 As this Court noted in its remand order, the legislative 

history of the ESA indicates that Congress did not seek to make 

any single factor controlling when drawing the distinction 

between an endangered and a threatened species, nor did it seek 

to limit the applicability of the endangered category to only 

those species facing imminent extinction. See In re Polar Bear, 

748 F. Supp. 2d at 28.
- 41 -

CBD also claims that the Service unlawfully discounted or 

otherwise failed to consider key scientific information in 

determining that the polar bear was not endangered in any 

portion of its range. Indeed, CBD claims that FWS never 

actually analyzed whether, at the time of listing, polar bears 

fit within any of the four categories of endangered species 

described in its Supplemental Explanation. According to CBD, 

the administrative record demonstrates that the polar bear fits

within three of the four “endangered” classifications identified 

by the agency. 

With respect to Category One, CBD asserts that FWS never 

considered whether global warming constitutes a “catastrophic 

threat.” CBD contends, as it did in its original briefing, that 

polar bears in at least the Seasonal and Divergent Ice 

Ecoregions face such a threat, and did at the time of listing, 

because the best available science at the time indicated that a 

certain amount of warming is already committed through the end 

of the 21st century and that continued warming trends are 

unlikely to be reversed in the near future. CBD points 

specifically to the USGS population modeling exercises, which 

projected declines in all of the polar bear ecoregions through 

mid-century, or approximately over a 45-year period. CBD also

cites to evidence in the record, including the Listing Rule 

itself, which suggests that these models are only conservative 
- 42 -

estimates of the potential impacts to polar bears from sea ice 

losses. See ARL 117275 (“Simulated and projected rates of 

habitat loss during the late 20th and early 21st centuries by 

many [climate models] tend to be less than observed rates of 

loss during the past two decades; therefore, habitat losses 

based on [these models] were considered to be conservative.”);

ARL 117280 (“The record low sea ice conditions of 2007 are an 

extension of an accelerating trend of minimum sea ice conditions 

and further support the concern that current sea ice models may 

be conservative and underestimate the rate and level of change 

expected in the future.”). 

In addition to the USGS population monitoring exercises, 

CBD references population-specific studies to suggest that three 

populations – Western Hudson Bay, Southern Beaufort Sea, and 

Baffin Bay – were in danger of extinction at the time of 

listing. Reports in the record from the international Polar 

Bear Specialist Group indicate that six of the nineteen polar 

bear populations were declining at the time of listing, 

including these three. The Western Hudson Bay population saw a 

decline of twenty-two percent (22%) over an eighteen year period

and showed statistically significant declines in body mass among 

female bears, ARL 117271, which must maintain a certain body 

weight to successfully reproduce, ARL 117270. Researchers 

estimated that cub production in this population would “probably
- 43 -

be negligible within the next 15-25 years.” ARL 117270. 

Population numbers also declined in the Southern Beaufort Sea 

population, along with significant cumulative declines in 

observed cub survival and skull size and adult male body mass 

and skull size. See ARL 117272. Unprecedented instances of 

starvation and cannibalism among the Southern Beaufort Sea were 

also reported and attributed to nutritional stress. See ARL 

117272. 

Finally, CBD points to a letter from the Marine Mammal 

Commission (“MMC”),25 the agency charged with advising FWS on 

marine mammal issues, which urged FWS to list the polar bear as 

endangered in light of the USGS population modeling reports. 

See ARL 126312. In its letter, MMC concluded that “[w]hen taken 

as a whole, [the USGS reports] present a bleak picture of the 

 25 MMC is a non-executive agency created by the Marine Mammal 

Protection Act (“MMPA”). 16 U.S.C. §§ 1403, 1406. The MMPA 

does not require FWS to follow the MMC’s recommendations but 

only requires FWS to respond to MMC and explain its reasoning if 

those recommendations are not followed. Id. § 1402(d); see also 

ARL 108484. The Court notes that MMC provided two sets of 

comments on the listing decision and comments as a peer reviewer 

on the Service’s earlier status assessment for the polar bear. 

MMC’s comments on the status assessment and its first set of 

comments on the proposed listing supported the Service’s rangewide “threatened” designation for the polar bear. See ARL 

18533; ARL 61800; ARL 126309. In its second set of comments, 

referenced here, MMC recommended listing the polar bear as 

endangered because of USGS population projections for the 

Seasonal and Divergent Ice ecoregions. See ARL 126309. FWS 

responded to MMC’s recommendation by letter dated June 17, 2008. 

AR4D 14233 (final response dated June 17, 2008 included in the 

administrative record for the Interim 4(d) Rule); see also ARL 

108485 (draft response dated Feb. 28, 2008). 
- 44 -

survival prospects of most populations of polar bears, absent 

rigorous management of the underlying factors driving climate 

change.” ARL 126315. According to CBD, this letter supports a 

conclusion that the agency acted arbitrarily in failing to find 

that the polar bear was endangered throughout a significant 

portion of its range at the time the agency made its decision. 

With respect to Category Two, CBD asserts that FWS never 

considered whether the polar bear should be considered a 

“narrowly restricted endemic” species facing elevated threats. 

By contrast, CBD contends that the polar bear should be 

considered an endemic species because it relies exclusively on a 

particular type of sea ice habitat. FWS acknowledged that this 

habitat type is at risk from continued warming patterns; indeed, 

this conclusion forms the basis for the agency’s decision to 

list the species as threatened. As such, CBD argues that the 

agency was obligated to consider whether the polar bear should 

have properly been classified as endangered because of its 

unique habitat needs and the particular threats to that habitat 

from climate change. 

Finally, with respect to Category Four, CBD asserts that 

the agency failed to consider whether any polar bear population 

“‘suffered ongoing major reductions in its numbers, range, or 

both, as a result of factors that have not been abated.’” CBD 

Supp. Mem. at 24 (quoting Supp. Exp. at 6). At the least, CBD 
- 45 -

contends that a twenty-two percent decline in the Western Hudson 

Bay population should have been considered a “major decline in 

numbers.” CBD Supp. Mem. at 24. 

CBD also points out that, although the polar bear was the 

first species to be listed due to climate change, FWS never 

considered whether the existence of a new threat might warrant 

the creation of an altogether new category. Instead, CBD 

contends, the agency relied on flawed conclusions, incorrect 

assumptions, and an unreasonably narrow interpretation of the 

statute to justify a lower level of protection for the polar 

bear than the species demands. According to CBD, the agency 

consistently failed to articulate a rational connection between 

the record evidence and the choice it made. For these reasons, 

CBD argues that the Service’s interpretation of the definition 

of “endangered species” to exclude the polar bear was arbitrary, 

capricious, and manifestly contrary to the text, structure, and 

purpose of the ESA. 

c. The Court’s Analysis

As a threshold matter, the parties disagree on whether the 

Court is obliged to review the statutory interpretation set 

forth in the agency’s Supplemental Explanation under the 

deferential Chevron framework, or whether another standard 

should guide the Court’s review on remand. Before reaching the 

merits of the agency’s Supplemental Explanation, the Court must 
- 46 -

first determine the appropriate standard of review. The Court 

turns now to that question.

i. Standard of Review on Remand

As noted above, where a court reviews an agency’s 

interpretation of a statute it is charged with administering, 

such as the ESA, the Supreme Court’s opinion in Chevron, U.S.A., 

Inc. v. Natural Resources Defense Council, Inc. provides the 

appropriate framework of review. Here, the federal defendants, 

the defendant-intervenors, and the Joint Plaintiffs concur that 

this Court, having found that the agency’s plain-meaning 

interpretation of the definition of an endangered species fails 

under step one of the Chevron framework, should now analyze the 

agency’s Supplemental Explanation under step two of Chevron, 

which requires the Court to uphold any reasonable agency 

interpretation of ambiguous statutory language. See 467 U.S. at 

843-44. Plaintiff CBD contends, by contrast, that the agency’s 

Supplemental Explanation here is not “Chevron step two-worthy.” 

CBD Supp. Mem. at 4. 

Under the Supreme Court’s decision in United States v. 

Mead, an agency interpretation qualifies for Chevron review when 

it meets two requirements: (1) “when it appears that Congress 

delegated authority to the agency generally to make rules 

carrying the force of law,” and (2) “the agency interpretation 

claiming deference was promulgated in the exercise of that 
- 47 -

authority.” 533 U.S. at 226-27; see also Pub. Citizen, Inc. v. 

HHS, 332 F. 3d 654, 659 (D.C. Cir. 2003) (citing Mead standard). 

According to CBD, the agency’s Supplemental Explanation meets 

neither of these requirements. Indeed, CBD goes further, 

arguing that the agency’s Supplemental Explanation is entitled

to no deference at all. Where a Chevron analysis is 

inappropriate, the Supreme Court has held that an agency 

interpretation may nonetheless be entitled to “respect,” but 

only to the extent that interpretation has the “power to 

persuade.” Skidmore v. Swift & Co., 323 U.S. 134, 140 (1944);

see also Power v. Barnhart, 292 F.3d 781, 786 (D.C. Cir. 2002) 

(“Under Skidmore, we grant an agency’s interpretation only so 

much deference as its persuasiveness warrants.”). CBD asserts 

that the agency’s Supplemental Explanation has no “power to 

persuade” because it is inconsistent with the statute’s text, 

legislative history, and policy objectives, and because it is 

effectively post hoc rationalization, developed directly in 

response to litigation. Accordingly, CBD concludes, the 

agency’s interpretation of the statutory phrase “in danger of 

extinction” does not warrant deference under either the Chevron

or the Skidmore standard, and this Court “must decide for itself 

the best interpretation of ‘in danger of extinction’ as applied 

to the polar bear.” CBD Supp. Mem. at 9 (citing Landmark Legal 

Found. v. IRS, 267 F.3d 1132, 1136 (D.C. Cir. 2001)). 
- 48 -

After careful consideration of these arguments, the Court 

nevertheless concludes that Chevron provides the appropriate 

standard of review on remand. This Court remanded the Listing 

Rule to FWS for the very limited purpose of providing additional 

explanation for its listing determination for the polar bear. 

In other cases remanding an agency decision for a similarly 

limited purpose, the D.C. Circuit has subsequently reviewed the 

agency’s supplemental analysis under the Chevron framework. See 

Sec’y of Labor v. Nat’l Cement Co. of Cal., 573 F.3d 788, 793 

(D.C. Cir. 2009) (concluding that “the Secretary’s 

interpretation [on remand] is entitled to Chevron deference”); 

PDK Labs., Inc. v. DEA, 438 F.3d 1184, 1189-90 (D.C. Cir. 2006) 

(“This leaves us with the task of resolving at Chevron’s second 

step whether the Deputy Administrator’s resolution of that

ambiguity [on remand] is based on a permissible construction of 

the statute.”). 

Indeed, the D.C. Circuit recently addressed this precise 

question in Menkes v. U.S. Department of Homeland Security, 637 

F.3d 319 (D.C. Cir. 2011). In Menkes, as here, the D.C. Circuit 

remanded to the Coast Guard for a “forthright” agency 

interpretation of ambiguous statutory language in the Great 

Lakes Pilotage Act. Although the plaintiff in that case argued 

that the agency’s response on remand was not entitled to 

deferential Chevron review, the D.C. Circuit disagreed. 
- 49 -

Specifically, the court found that Chevron deference was 

appropriate because the Coast Guard was acting “pursuant to an 

express delegation from Congress” and because its interpretation 

addressed “interstitial questions” that the agency “deserve[d] 

deference to address.” Id. at 331-32 (citing Barnhart v. 

Walton, 535 U.S. 212, 222 (2002); see also Mylan Labs., Inc. v. 

Thompson, 389 F.3d 1272, 1280 (D.C. Cir. 2004)). The court 

found that the agency was not required to conduct notice-andcomment rulemaking procedures or engage in a formal adjudicatory 

process for its statutory interpretation to warrant deferential 

review. Menkes, 637 F.3d at 332-33. Rather, the court 

concluded that “the Coast Guard’s enunciation of the aforecited 

statutory interpretations and rules has the ‘force of law,’ 

. . . especially given the instruction from this court to the 

agency to ‘come to grips with the meaning of the statute.’” Id.

at 332. 

Because this Court finds that the court’s opinion in Menkes

bears directly on the question before it, it is bound to follow 

the D.C. Circuit’s approach. Here, as in Menkes, the Court 

required the Service to grapple with the ambiguities in the 

ESA’s definition of the term “endangered species,” pursuant to 

the agency’s express authority to make listing determinations 

case-by-case in light of the best available science for each 

species. The Court expressly did not require the agency to 
- 50 -

adopt independent, broad-based criteria or prospective policy 

guidance regarding the interpretation of the phrase “in danger 

of extinction” in the ESA. Further, the Court expressly did not 

require the agency to conduct notice-and-comment rulemaking 

procedures or to engage in additional fact-finding. Given the 

narrow scope of the remand order in this case, the Court is 

persuaded that the agency’s Supplemental Explanation qualifies 

for deferential review under Chevron.26

ii. Merits

As set forth below, having carefully considered the 

agency’s Supplemental Explanation, the parties’ arguments 

contained in both the original and supplemental briefing, and 

the relevant case law, the Court finds that it must uphold the 

Service’s conclusion that the polar bear was not endangered at 

the time of listing under step two of the Chevron framework. 

 26 While the Court is sensitive to CBD’s concerns that the 

agency’s Supplemental Explanation may constitute post hoc 

rationalization, it finds persuasive the D.C. Circuit’s 

reasoning in Alpharma, Inc. v. Leavitt, 460 F.3d 1,6 (D.C. Cir. 

2006), in which the court noted that it would make no sense for 

a court to order a remand for supplemental explanation only to 

then reject that explanation as post hoc rationalization. 

Moreover, the Court is persuaded that the agency’s Supplemental 

Explanation does not constitute impermissible post hoc

rationalization because the agency decision-makers themselves 

developed and approved it. See Pub. Citizen v. FMCSA, 374 F.3d 

1209, 1218 (D.C. Cir. 2004) (noting that “[t]he expertise of the 

agency . . . must be brought to bear” (citation omitted)). 
- 51 -

As an initial matter, the Court finds that the agency’s

general understanding that an endangered species is “on the 

brink of extinction” is not clearly out of line with 

Congressional intent.27 With that said, however, the agency’s 

general understanding of the definition of an endangered species 

is not the primary focus of the Court’s inquiry. Rather, as the 

Court recognized in its remand order, the decision to list a 

species as threatened or endangered is highly fact-specific. 

See In re Polar Bear, 748 F. Supp. 2d at 28. On remand, the 

agency maintains that the facts in the administrative record 

show that the polar bear was not endangered as of 2008. The 

relevant question before this Court, therefore, is whether that

conclusion was a reasonable one. 

As discussed above, plaintiff CBD contends that the 

agency’s conclusion is flawed because FWS improperly ignored or 

discounted relevant factors. This Court disagrees. The Court 

is not persuaded that the agency ignored or otherwise failed to 

 27 The agency’s determination that an endangered species is 

“on the brink of extinction” draws from the primary distinction 

between the categories of threatened and endangered species as 

set forth in the text of the ESA. As this Court has previously 

observed, there is a temporal element to the distinction between 

the categories of endangered and threatened species. See In re 

Polar Bear, 748 F. Supp. 2d at 26. This temporal distinction is 

also frequently noted in the legislative history. See id. at 28

(noting that the legislative history emphasizes that an 

endangered species “is” (currently or presently or actually) in 

danger of extinction, whereas a threatened species is “likely to 

become” so endangered).
- 52 -

consider any of the information cited by plaintiff CBD. All of 

that information – including the population modeling data and 

polar bear monitoring reports – is included in the voluminous 

administrative record that was before the agency and, indeed, 

much of that data was cited by the agency as a basis for 

designating the polar bear as a threatened species. Notably, 

CBD cites to the agency’s findings in the Listing Rule itself 

for much of the evidence that it claims the agency ignored. 

To the extent that CBD is asking this Court to find that 

FWS drew improper conclusions from the scientific information it 

considered, the Court declines to do so. Although the evidence 

emphasized by CBD is very troubling, the Court finds that the 

agency acted well within its discretion to weigh the available 

facts and scientific information before it in reaching its 

conclusion that the polar bear was not endangered at the time of 

listing.28 Where an agency has exercised its Congressionally-

 28 Certainly, where global warming has been identified as the 

primary threat to the polar bear’s sea ice habitat and the 

agency has acknowledged that the global warming trend is 

unlikely to reverse itself, a conclusion that the species is, in 

some sense, “in danger of extinction” has undeniable appeal. 

The USGS population models, which predict a trend of extinction 

across three of the four polar bear ecoregions in as little as 

75 years, particularly give the Court pause. However, the Court 

cannot agree with CBD that the agency’s conclusions based on the 

record, including these population models, rise to the level of 

irrationality. Specifically, the Court accepts as reasonable 

the agency’s explanation that it declined to find that these 

preliminary, alpha-level population models, which came 

relatively late in the decision-making process, were 
- 53 -

authorized discretion to weigh the relevant factors, and it has 

made a listing determination based on a reasoned choice, the 

Court will not disturb its conclusion. See Animal Legal Def. 

Fund v. Glickman, 204 F.3d 229, 235 (D.C. Cir. 2000) (“Where 

Congress delegates power to an agency to regulate on the borders 

of the unknown, courts cannot interfere with reasonable 

interpretations of equivocal evidence.”). While CBD would have 

weighed the facts differently, the Court is persuaded that FWS 

carefully considered all of the available scientific information 

before it, and its reasoned judgment is entitled to deference. 

Finally, the Court is satisfied that the agency has 

complied with its remand order to provide additional explanation 

for the agency’s original “threatened” listing. Plaintiff CBD 

has identified no compelling evidence demonstrating that the 

agency’s proffered interpretation of the ESA is manifestly 

contrary to the statute. Accordingly, the Court concludes that

the agency’s Supplemental Explanation sufficiently demonstrates 

that the Service’s definition of an endangered species, as 

applied to the polar bear, represents a permissible construction 

of the ESA and must be upheld under step two of the Chevron

 

sufficiently persuasive to warrant an “endangered” listing for 

the polar bear. 
- 54 -

framework.29 See Serono Labs. v. Shalala, 158 F.3d 1313, 1321 

(D.C. Cir. 1998) (under deferential Chevron framework, a court 

must uphold a reasonable construction of the statute, even if it 

believes that another interpretation is more reasonable).

2. Joint Plaintiffs’ Claim that the Polar Bear 

Should Not Have Been Considered Threatened at the 

Time of Listing

The Court turns now to Joint Plaintiffs’ claim that FWS 

similarly misinterpreted and misapplied the ESA when it 

concluded that the polar bear is likely to become endangered 

within the foreseeable future and thus qualified for threatened 

status at the time the agency made its listing determination. 

Joint Plaintiffs argue, first, that FWS failed to demonstrate 

that the polar bear is sufficiently “likely” to become 

endangered and, second, that FWS arbitrarily selected a 45-year 

time period as the “foreseeable future” for the polar bear, when 

a shorter time period would have been more appropriate. Each of 

these arguments is addressed in turn. 

 29 Because the Court finds that the agency reasonably 

concluded that the polar bear was not in danger of extinction in 

any portion of its range at the time of listing, the Court will

not address CBD’s related argument that the Seasonal and 

Divergent Ice Ecoregions constitute a “significant portion” of 

the polar bear range. See 16 U.S.C. § 1532(6). 
- 55 -

a. Joint Plaintiffs’ Argument that the Service

Failed to Demonstrate that the Polar Bear Is 

67-90% Likely to Become Endangered

A threatened species under the ESA is a species that is 

“likely to become an endangered species within the foreseeable 

future throughout all or a significant portion of its range.”

16 U.S.C. § 1532(20). Joint Plaintiffs claim that FWS failed to 

prove that the polar bear is sufficiently “likely” to become 

endangered within the meaning of this definition. Specifically, 

Joint Plaintiffs contend that FWS failed to demonstrate a 67-90% 

likelihood that the polar bear will become endangered within the 

foreseeable future. 

As an initial matter, Congress did not define the term 

“likely” in the ESA. FWS has not adopted regulations or other 

guidance defining the term. Nor has any court defined the 

term.30 Joint Plaintiffs look instead to the IPCC’s Fourth 

Assessment Report (“IPCC AR4”), which provides that, for the 

purposes of its climate models and projections, a “likely”

 30 The District of Oregon in Trout Unlimited v. Lohn is the 

only court to have significantly discussed the term “likely” as 

it appears in the ESA. 645 F. Supp. 2d 929 (D. Or. 2007). In 

that case, the district court declined to define the term but 

upheld as reasonable the National Marine Fisheries Service’s 

interpretation of the term to mean “more likely than not.” Id. 

at 944. The “more likely than not” standard has also previously 

been adopted by FWS in interpreting the “threatened” designation 

under the ESA. See W. Watersheds Project v. U.S. Forest Serv., 

535 F. Supp. 2d 1173, 1184 (D. Idaho 2007). 
- 56 -

outcome is one that has a 67-90% probability of occurring.31 ARL 

151195 n.6. Joint Plaintiffs assert that this standard of 

likelihood is relevant not only because FWS relied in part on 

the climate models in the IPCC AR4 in reaching its “threatened”

determination for the polar bear, but also because FWS itself 

purportedly adopted this numerical standard of likelihood for 

the purposes of making its listing decision. In support of this 

argument, Joint Plaintiffs point specifically to a statement in 

the agency’s response to comments on the proposed rule, in which 

FWS noted that it “attempted to use [the terms “unlikely,”

“likely,” and “very likely”] in a manner consistent with how 

they are used in the IPCC AR4.” ARL 117241. According to Joint 

Plaintiffs, therefore, this statement indicates that the agency 

adopted this high numerical standard of likelihood for all 

purposes, including statutory interpretation of the term 

“likely” as it appears in the ESA.32

 31 According to IPCC standards, a “more likely than not” 

outcome has a 50-66% probability of occurring. A “very likely”

outcome is one that has more than a 90-95% probability of 

occurring; an “extremely likely” outcome has a 96-99% 

probability of occurring; and a “virtually certain” outcome has 

a greater than 99% probability of occurring. ARL 151195 n.6. 

32 In their reply brief, Joint Plaintiffs raise the 

alternative argument that even if FWS did not specifically adopt 

this particular numerical standard, the Listing Rule should then 

be overturned because the agency failed to adopt any standard 

for determining whether the polar bear is “likely” to become 

endangered. See JP Reply, Docket No. 170, at 14. To the extent 

the Court considers this new argument that was raised improperly 
- 57 -

In making this argument, it is not Joint Plaintiffs’ 

position that FWS adopted an impermissible construction of the 

statute. To the contrary, Joint Plaintiffs appear to suggest

that a 67-90% standard of likelihood would be reasonable. See 

JP Mot. at 10 (noting that 67-90% is consistent with dictionary 

definition of the term “likely”). Instead, Joint Plaintiffs 

assert that, having adopted this high standard, FWS subsequently

failed to meet that standard when it relied on highly uncertain 

climate and population modeling. For this reason, Joint 

Plaintiffs conclude, the agency’s determination that the polar 

bear is likely to become endangered was arbitrary and 

capricious. 

The federal defendants respond that FWS did not adopt any 

numerical definition of the term “likely” in the Listing Rule, 

let alone the unreasonably high standard of 67-90%. They assert 

that Joint Plaintiffs have simply taken out of context a 

statement that was intended to refer only to the standards used 

to assess the reliability of climate models, which is “entirely 

separate from the ultimate standard under the ESA for 

determining whether a species meets the statutory definition of 

threatened based on the entirety of the available science and 

 

for the first time on reply, the Court is persuaded that the 

agency articulated a reasoned basis for its listing 

determination for the polar bear, notwithstanding the fact that 

it did not purport to define the term “likely” in its Listing 

Rule. 
- 58 -

the five listing factors.” Fed. Def. Mot. at 56. Indeed, the 

federal defendants point out that the very next sentence of the 

agency’s response to comments refers explicitly to “the 

limitations and uncertainties of the climate models and their 

projections.” ARL 117241. This statement suggests that the 

agency intended to apply the numerical standard cited by Joint 

Plaintiffs only to those climate models, which are only part of 

a voluminous administrative record, and not more broadly. 

According to the federal defendants, because Joint Plaintiffs 

incorrectly assume that the agency adopted a quantitative 

definition of the term “likely,” their attempt to show noncompliance with this standard must fail.33

The threshold question before the Court, therefore, is 

whether FWS in fact adopted the Joint Plaintiffs’ proffered 

numerical definition of the term “likely.” Having carefully 

reviewed the administrative record, the Court is not persuaded 

that FWS adopted a numerical standard of 67-90% probability in 

determining whether the polar bear is “likely” to become 

endangered. Although the only arguable definition of the term 

“likely” in the Listing Rule appears in the response to comments 

that Joint Plaintiffs have highlighted, the Court agrees with 

 33 The federal defendants also argue that, regardless of how 

the term “likely” could be numerically defined, the agency’s 

determination for the polar bear easily would meet that 

standard. 
- 59 -

the federal defendants that this lone statement does not 

demonstrate the agency’s intent to adopt the IPCC’s numerical 

standards for all purposes, including statutory construction. 

Indeed, a close review of the record belies any such 

intention. The record reveals that FWS used the terms “likely”

and “very likely” interchangeably throughout its Listing Rule. 

See, e.g., ARL 117245 (“Because of the habitat changes 

anticipated in the next 40-50 years, and the corresponding 

reductions in reproduction and survival, and, ultimately, 

population numbers, we have determined that the polar bear is 

likely to be in danger of extinction throughout all or a 

significant portion of its range by 2050.” (emphasis added)); 

ARL 117252 (“[W]e conclude that the species is not currently in 

danger of extinction throughout all or a significant portion of 

its range, but is very likely to become so within the 

foreseeable future.” (emphasis added)). The Court concludes 

that if FWS had intended to imbue these terms with the 

mathematical precision urged by Joint Plaintiffs for the 

purposes of statutory construction, it would have used these 

terms more deliberately. 

Because the Court finds that FWS did not adopt a statutory 

interpretation that would require a showing that at the time of 

listing the polar bear had a 67-90% likelihood of becoming 

endangered within the foreseeable future in order to be listed 
- 60 -

as a threatened species, the Court declines to reach Joint 

Plaintiffs’ claim that the agency failed to make such a showing. 

Accordingly, the Court concludes that the Listing Rule is not 

arbitrary and capricious on these grounds. 

b. Joint Plaintiffs’ Argument that the Service

Arbitrarily Selected 45 Years As the 

“Foreseeable Future” Timeframe for the Polar 

Bear

The Court turns now to Joint Plaintiffs’ argument that the 

Service’s choice of a “foreseeable future” timeframe over which 

the polar bear is likely to become endangered was arbitrary and 

capricious. In its Listing Rule, FWS defined the “foreseeable 

future” as “the timeframe over which the best available 

scientific data allow us to reliably assess the effects of 

threats on the polar bear,” and it concluded based on record 

evidence that it could confidently predict potential impacts to 

the polar bear from sea ice losses over a 45-year period. ARL 

117257. Joint Plaintiffs argue that the agency’s choice of 45 

years as the foreseeable future for the polar bear was arbitrary 

and was based on inappropriate factors.34 They further contend 

 34 Plaintiff CBD also challenges the Service’s choice of a 45-

year timeframe for the polar bear. Plaintiff CBD contends that 

the “foreseeable future” for the polar bear should be extended 

beyond 45 years to the year 2100. The Court finds CBD’s claim 

perplexing. The basis of CBD’s argument appears to be that 

impacts to the polar bear over the next 100 years were not only 

foreseeable at the time of listing but were also drastic enough 

to warrant listing the species as endangered. By definition, 

however, a “foreseeable future” determination is only relevant 
- 61 -

that FWS erred when it failed to consider whether any time 

period shorter than 45 years would be more appropriately 

foreseeable. The Court will address these arguments in turn. 

Joint Plaintiffs raise two significant arguments in support 

of their claim that the 45-year time period was arbitrarily 

chosen. First, Joint Plaintiffs claim that the agency’s choice 

of a 45-year time period was inappropriately based only on 

biological factors (e.g., life history characteristics of the 

polar bear) rather than on what the agency could actually 

foresee. Citing to the proposed rule for the polar bear, Joint 

Plaintiffs assert that FWS initially chose a 45-year timeframe 

because it corresponds roughly to three polar bear generations.35

According to Joint Plaintiffs, FWS later modified its analysis 

at the final rule stage in an attempt to justify its arbitrary 

 

for threatened species. See 16 U.S.C. § 1532(20). FWS 

determined that impacts to the polar bear over the next 45 years

were sufficiently foreseeable to warrant listing the species as 

threatened as of 2008. Therefore, impacts to the polar bear 

beyond year 45 were not relevant to the agency’s listing 

determination. 

35 Joint Plaintiffs also argue that, to the extent FWS relied 

on biological considerations, FWS incorrectly calculated the 

generation length of a polar bear. As the federal defendants 

point out, Joint Plaintiffs never raised this point before the 

agency, and it is well-established in this Circuit that issues 

not raised before the agency are waived. See Nat’l Wildlife 

Fed’n v. EPA, 286 F.3d 554, 562 (D.C. Cir. 2002). Even assuming 

the argument is not waived, however, plaintiffs point to no 

evidence suggesting that a different calculation of polar bear 

generation length would render the agency’s conclusion arbitrary 

and capricious. 
- 62 -

choice by pointing to sources of scientific data, including IPCC 

reports and other climate projections. Second, Joint Plaintiffs 

argue that FWS should have considered what is “foreseeable” with 

respect to all five of the ESA’s statutory listing factors 

(i.e., habitat loss, overutilization, regulatory mechanisms, 

disease, and other manmade factors). This kind of comprehensive 

review, Joint Plaintiffs argue, would have enabled the agency to 

make a more accurate assessment of the species’ likelihood of 

becoming endangered because other factors may offset a 

foreseeable threat. Focusing specifically on regulatory 

mechanisms (“Listing Factor D”), Joint Plaintiffs contend that 

“because the Service cannot reasonably ‘foresee’ or predict 

anything about existing regulatory mechanisms in 45 years, that 

period is too long.” JP Mot. at 14. 

The federal defendants respond that FWS reasonably defined 

the foreseeable future as 45 years because it found that it 

could make confident forecasts about polar bear population 

trends up to that point, based on climate modeling and other 

reliable data. Specifically, the federal defendants assert, 

climate change projections from the IPCC AR4 supported a 45-year 

foreseeable future timeframe at the time of listing. As the 

federal defendants describe, model outcomes reported in the IPCC 

AR4, which FWS accepted as the best available science on climate 

change, consistently predict a certain base level of overall 
- 63 -

warming through mid-century, regardless of whether actual 

emissions increase or decrease over that period. Fed. Def. Mot. 

at 73 (citing ARL 117279). FWS found, relying on these IPCC 

reports, that beyond that point the choice of emission scenario 

begins to influence model outcomes more significantly. See ARL 

117233. According to FWS, therefore, at the time the agency 

made its listing decision minimum impacts to Arctic sea ice

could be predicted with confidence for up to fifty years but 

projections became more speculative beyond that point.

As the federal defendants point out, FWS also acknowledged 

that a 45-year period roughly corresponds to three polar bear 

generations. However, according to the federal defendants, the 

agency found this correlation to be relevant because population 

status projections will generally be even more reliable if they 

correspond in some way to the life history characteristics of 

the species. See ARL 117258. Specifically, the federal 

defendants assert, FWS determined that population projections 

that can be made over multiple polar bear generations are more 

reliable than projections that only span one generation. The 

federal defendants contend that it was not irrational for FWS to 

rely on biological factors in this way to support its choice of 

a foreseeable future timeframe for its listing decision. 

With respect to Joint Plaintiffs’ argument that FWS erred 

when it failed to consider what is “foreseeable” for all five 
- 64 -

listing factors, and particularly Listing Factor D (“existing 

regulatory mechanisms”), the federal defendants respond that the 

statute contains no such requirement. Indeed, the federal 

defendants assert, the “suggestion that the Service could forego 

listing the polar bear under Factor D based on wholly 

speculative and uncertain future regulatory mechanisms is 

contrary to the ESA.” Fed. Def. Mot. at 75. Moreover, there is 

no evidence in the record, according to the federal defendants, 

that any regulatory mechanisms have been or will be implemented 

that would effectively address the loss of sea ice within the 

foreseeable future. As such, the federal defendants conclude, 

Joint Plaintiffs’ argument lacks merit. 

As with the term “likely,” Congress has not defined the 

term “foreseeable future” under the ESA, and FWS has not 

promulgated any regulations or other policy guidance defining 

the term. At least one court has recognized that what is 

“foreseeable” is likely to vary from species to species 

depending on a number of factors and, therefore, a bright-line 

rule of foreseeability is inappropriate. See W. Watersheds 

Project v. Foss, No. 06-1574, 2005 U.S. Dist. LEXIS 45753, at 

*44-45 (E.D. Pa. Aug. 19, 2005) (noting that “the definition of 

‘foreseeable future’ may vary depending on the particular 

species - for example, ‘foreseeable future’ may be defined 

differently for a sequoia tree . . . than for the slickspot 
- 65 -

peppergrass, which is an annual or biennial plant”). In the 

absence of a quantitative standard, a “foreseeable future”

determination is made on the basis of the agency’s reasoned 

judgment in light of the best available science for the species 

under consideration. See id. (declining to establish a brightline rule but noting that the agency must articulate a 

satisfactory explanation for its definition). 

Having carefully considered the parties’ arguments and the 

administrative record, the Court rejects Joint Plaintiffs’ 

argument that the choice of a 45-year foreseeable future 

timeframe for the polar bear was arbitrary and based on improper 

considerations. Contrary to Joint Plaintiffs’ assertions, FWS

does not appear to have based its choice solely on biological 

factors, even at the proposed rule stage. To the extent this 

Court considers the agency’s proposed rule, which is not the 

action before it on review, the Court finds that the agency 

sufficiently explained that its decision was based on “IUCN 

criteria,36 the life-history and population dynamics of polar 

bears, documented changes to date in both multi-year and annual

 36 A 45-year time period for the foreseeable future is 

consistent with the work of the international Polar Bear 

Specialist Group, which reassessed the status of the polar bear 

in June 2005 for the purposes of the International Union for the 

Conservation of Nature’s (“IUCN”) Red List classification, a 

list of species considered to be threatened. ARL 117258. 

Although the standards for Red Listing classification differ 

from ESA listing standards, FWS nonetheless found the IUCN 

assessment to be instructive. See ARL 117254.
- 66 -

sea ice, and the direction of projected rates of change of sea 

ice in future decades,” which all supported a 45-year or threegeneration timeframe for the foreseeable future. ARL 59992. 

Moreover, the final Listing Rule indicates that the climate 

change projections found in the IPCC AR4 – and not biological 

factors – were the primary basis for the Service’s determination 

of the foreseeable future timeframe. See ARL 117257. In light 

of the IPCC AR4 findings, the Court is satisfied that the agency 

articulated a rational basis for its choice. 

The Court also rejects Joint Plaintiffs’ argument that FWS 

erred by failing to “foresee” future developments with respect 

to all five listing factors over the next 45 years. Notably, 

Joint Plaintiffs do not contend that the ESA required FWS to 

conduct such an analysis; they assert only that it would have 

resulted in a more accurate conclusion. Here, however, a review 

of the Listing Rule reveals that the agency in fact took all 

five listing factors into account, and it considered whether

those factors would affect the likelihood that the polar bear 

will become endangered within the foreseeable future. With 

respect to overutilization (“Listing Factor B”), for example, 

the agency found that harvest “is likely exacerbating the 

effects of habitat loss in several populations” and that polar 

bear mortality from harvest “may in the future approach 

unsustainable levels for several populations” as these 
- 67 -

populations begin to experience the stresses of habitat change. 

ARL 117284. Further, with respect to regulatory mechanisms

(“Listing Factor D”), the agency concluded that there are no 

known regulatory mechanisms that could effectively address the 

primary threat to the polar bear from future sea ice losses.37 

To the extent the agency was required to consider other listing 

factors, the Court is satisfied that FWS did so.

Finally, Joint Plaintiffs argue that even though FWS 

considered impacts to the polar bear over a 45-year time period 

to be reasonably foreseeable, FWS nonetheless erred when it 

failed to consider a shorter timeframe, which would likely be

more foreseeable. The applicable standard, however, is not 

whether the agency could have taken a more reasonable approach. 

The agency must only show that the approach it took was a 

rational one. See Envtl. Def. Fund v. Costle, 657 F.2d 275, 283 

(D.C. Cir. 1981) (“[The APA standard] mandates judicial 

affirmance if a rational basis for the agency’s decision is 

presented . . . even though [a court] might otherwise 

disagree.”). Although Joint Plaintiffs may have less confidence 

 37 The ESA does not require FWS to “foresee” what regulatory 

mechanisms will be in place in the future - it is only required 

to take existing regulatory mechanisms into account in its 

listing determination. 16 U.S.C. § 1533(a)(1)(D); Biodiversity 

Legal Found. v. Babbitt, 943 F. Supp. 23, 26 (D.D.C. 1996); see 

also Or. Natural Res. Council v. Daley, 6 F. Supp. 2d 1139, 

1153-54 (D. Or. 1998). 
- 68 -

than FWS in the conclusions that the agency reached, that is not 

an appropriate basis for invalidating an agency’s rational 

choice, particularly in matters requiring scientific or 

technical expertise. See Marsh v. Or. Natural Res. Council, 490 

U.S. 360, 375-77 (1989). Accordingly, the Court concludes that 

FWS appropriately exercised its discretion in selecting a 45-

year “foreseeable future” timeframe for the polar bear. 

B. The Service Articulated a Rational Basis for Its 

Conclusion that No Polar Bear Population or Ecoregion 

Qualifies As a “Distinct Population Segment”

Whereas plaintiff CBD and Joint Plaintiffs primarily focus 

on the question of whether the polar bear warranted endangered 

or threatened status throughout its range in 2008, a subset of 

plaintiffs argue, in the alternative, that FWS should have 

differentiated among the various polar bear populations and/or 

ecoregions according to their relative levels of risk in making 

its listing decision. Specifically, plaintiffs CBD, SCI, and CF

assert that FWS erred when it declined to designate any polar 

bear population or ecoregion as a distinct population segment 

(“DPS”) under the ESA, which would have allowed the agency to 

tailor ESA protections more narrowly. The common question 

presented by these three plaintiffs is whether FWS arbitrarily 

determined that no polar bear population or ecoregion is 
- 69 -

sufficiently “discrete” for the purposes of a DPS designation.38

The Court turns now to that question.

1. The Service’s Policy 

The term “species” as it is used in the ESA includes “any 

distinct population segment of any species of vertebrate fish or 

wildlife which interbreeds when mature.” 16 U.S.C. § 1532(16)

(emphasis added). Congress did not further define the term 

“distinct population segment,” nor is the term defined in 

scientific discourse. In 1996, however, FWS and NMFS jointly 

promulgated a “Policy Regarding the Recognition of Distinct 

Vertebrate Population Segments Under the Endangered Species Act”

(“DPS Policy”), 61 Fed. Reg. 4722 (Feb. 7, 1996), which provides 

 38 In a related claim, plaintiffs SCI and CF further assert 

that FWS arbitrarily failed to consider using its authority to 

list the polar bear in only part of its range. Essentially, 

these plaintiffs claim that FWS erred by failing to consider 

whether any portion of the polar bear range did not warrant 

listing as threatened. The Court concludes that this claim has 

no merit. As a threshold matter, in light of recent court 

opinions, it is unclear whether the agency has the authority to 

list a species in only a portion of its range without going 

through the process of a DPS designation. See generally Federal 

Defendants’ Notice of Withdrawal of M-37013, Docket No. 258 

(citing Defenders of Wildlife v. Salazar, 729 F. Supp. 2d 1207 

(D. Mont. 2010)). Further, the Court finds that FWS 

sufficiently considered whether any portion of the polar bear 

population did not warrant listing under the ESA. This

assessment is implied in the agency’s conclusion that the polar 

bear did warrant listing throughout its range. FWS provided 

ample explanation in its Listing Rule for why polar bears rangewide are likely to become endangered within the foreseeable 

future and, as a result, warranted at least a “threatened”

designation. The Court is therefore persuaded that FWS did not 

arbitrarily fail to consider this issue. 
- 70 -

guidance to both agencies in applying the term “distinct 

population segment” for the purposes of an ESA listing. 

Pursuant to this policy, FWS may designate a DPS to avoid 

listing an entire species where only a portion of its population

warrants ESA protections. See Nat’l Ass’n of Home Builders v. 

Norton, 340 F.3d 835, 842 (9th Cir. 2003). 

The DPS Policy outlines three elements to be considered in 

evaluating a possible DPS:

1. The discreteness of the population segment in 

relation to the remainder of the species to which it 

belongs;

2. The significance of the population segment to the 

species to which it belongs; and

3. The population segment’s conservation status in 

relation to the Act’s standards for listing . . . . 

DPS Policy, 61 Fed. Reg. at 4725. These considerations are to 

be evaluated sequentially – i.e., FWS must first determine that 

the population segment is discrete before it can consider 

whether that segment is also significant. Id. If, however, a 

population segment is found to be both discrete and significant, 

FWS may consider whether that segment is threatened or 

endangered as defined by the ESA. Id.

A population segment is “discrete” when it satisfies either 

one of the following conditions: 

1. It is “markedly separated” from other populations of 

the same taxon as a consequence of physical, 

physiological, ecological, or behavioral factors. 

Quantitative measures of genetic or morphological 
- 71 -

discontinuity may provide evidence of this 

separation. 

2. It is delimited by international governmental 

boundaries within which differences in control of 

exploitation, management of habitat, conservation 

status, or regulatory mechanisms exist that are 

significant in light of [the five ESA listing 

factors]. 

Id. The test for discreteness under the agencies’ DPS Policy is 

not intended to be particularly rigid. Id. at 4724. For 

example, it does not require absolute reproductive isolation but 

allows for some interchange among population segments. Id. The 

purpose of the distinctness criterion is merely to ensure that a 

DPS can be reasonably defined and described in order to ensure 

effective administration and enforcement of the Act. Id.

Nonetheless, both the “discreteness” criterion and the 

“significance” criterion were adopted to ensure that FWS uses 

its authority to list DPS’s “sparingly,” at the urging of 

Congress. Id. at 4725 (citing S. Rep. No. 96-151, at 7 (1979)). 

DPS designation is primarily intended to enable protection and 

recovery of declining organisms in a more timely and less costly 

manner, and on a smaller scale, than would be required for an 

entire species or subspecies. DPS Policy, 61 Fed. Reg. at 4725. 

It is not a tactic for subdividing a larger population that FWS

has already determined, on the same information, warrants 

listing across a larger range. See Friends of the Wild Swan v. 

U.S. FWS, 12 F. Supp. 2d 1121, 1133 (D. Or. 1997). 
- 72 -

At least two courts have acknowledged that the term 

“distinct population segment” in the ESA is ambiguous, and, 

therefore, the agency’s interpretation and application of that 

term falls within step two of a Chevron analysis and is entitled 

to deference. See Nw. Ecosystem Alliance v. U.S. FWS, 475 F.3d 

1136, 1141-43 (9th Cir. 2007); State of Maine v. Norton, 257 F. 

Supp. 2d 357, 385 (D. Me. 2003). Both courts upheld the 

agency’s 1996 DPS Policy as a reasonable interpretation of the 

ESA.39 Nw. Ecosystem Alliance, 475 F.3d at 1145; State of Maine 

v. Norton, 257 F. Supp. 2d at 387. 

2. Plaintiffs CBD, SCI, and CF’s Claim that the 

Service Wrongly Concluded that No Polar Bear 

Population or Ecoregion Is “Discrete”

In its Listing Rule, FWS considered whether any distinct 

population segments exist for the polar bear. As an initial

matter, FWS considered whether any polar bear population or 

ecoregion is “discrete” within the meaning of its DPS Policy. 

The agency determined that, while different populations exhibit 

minor differences of behavior, genetics, and life-history 

parameters, no population or geographic area is markedly 

separated as a consequence of physical, physiological, 

ecological, or behavioral factors. ARL 117298. In the 

Service’s estimation, the minor differences between individual 

 39 The DPS Policy itself has not been challenged by any party 

in this case and is not before this Court on review. 
- 73 -

populations and ecoregions do not outweigh the similarities that 

are most relevant to the polar bear’s conservation status – in 

particular, the species’ universal reliance on sea ice habitat 

for critical life functions. ARL 117298. As the federal 

defendants note, “[w]hile polar bears adopt different strategies 

to deal with the seasonal absence of sea-ice . . . their 

response to declining sea ice is essentially the same, with the 

same negative result: they suffer nutritional stress because 

they spend longer amounts of time outside of their preferred

sea-ice habitats where seals are accessible.” Fed. Def. Mot. at 

104 (citing ARL 117274). Accordingly, FWS concluded that no 

portion of the polar bear population is sufficiently “discrete”

to qualify for designation as a DPS.

Plaintiffs CBD, CF, and SCI contend that, contrary to 

record evidence, FWS arbitrarily determined that no polar bear 

population is “markedly separated” from other populations.40 In 

 40 In addition to its claim that FWS reached a conclusion that 

is contrary to the evidence, CBD raises two additional claims: 

(1) that the agency failed to consider behavioral differences 

among the polar bear populations; and (2) that the agency failed 

to consider whether any ecoregion qualifies as a DPS. The Court 

cannot agree that the agency failed to consider either issue. 

First, FWS did acknowledge behavioral differences among polar 

bear populations but deemed these differences to be minor in 

comparison to their relevant similarities. See ARL 117298. 

Second, FWS appears to have considered whether any polar bear 

population segment - including ecoregions - qualifies as a DPS: 

Although polar bears within different populations or 

ecoregions (as defined by Amstrup et al. 2007) may 
- 74 -

support of their argument, plaintiffs point to evidence from the 

record which purportedly demonstrates that USGS scientists, 

polar bear experts, and the MMC all have identified distinctions 

among the world’s polar bear populations and, particularly, the 

four ecoregions. In light of this record evidence, plaintiffs 

argue that the Service’s conclusion that there is no marked 

separation among polar bear population groups was irrational. 

Plaintiff CBD points primarily to comments from various 

reviewers suggesting that the draft final listing rule did not 

adequately reflect the importance of the ecoregion structure for 

polar bears. For example, USGS reviewers noted: 

An important, and fairly emphatic, conclusion from the 

body of 2007 USGS work was that the life-history 

dynamics, demography, and present and future status of 

polar bears in the 4 ecoregions are different, owing 

largely to different ice dynamics, its spatiotemporal 

availability, how it has responded to global warming 

and how it is predicted to respond in the future. In 

these Ecoregions, the relationships between polar 

bears and their sea ice habitat are fundamentally 

different. 

See CBD Mot. at 38 (citing ARL 88920).

 

have minor differences in demographic parameters, 

behavior, or life history strategies, in general polar 

bears have a similar dependence upon sea ice habitats, 

rely upon similar prey, and exhibit similar life 

history characteristics throughout their range. 

ARL 117298 (emphasis added). Finally, FWS separately determined 

that the polar bear was not endangered in any portion of its 

range at the time of listing, including three specific 

populations and at least two ecoregions. See ARL 117299-301. 
- 75 -

USGS commenters also rejected the agency’s assessment in 

the draft final rule that “there are no morphological, or

physiological differences across the range of the species that 

may indicate adaptations to environmental variations.” CBD Mot. 

at 38 (citing ARL 96589). In response to this statement, USGS 

reviewers wrote: 

This statement does not seem to us to be true. We do 

see unique life history components that are related to 

where a polar bear lives within the overall range. 

That is, the polar bears in the seasonal ice ecoregion 

come ashore and fast for 4-8 months while polar bears 

in the polar basin may be on ice and never come to 

land – they may den on ice. . . . This statement seems 

to contradict the ecoregion idea – that there are some 

major differences in the ice regimes that do influence 

how polar bears make a living in the different parts 

of their range. 

ARL 96841. 

One particularly troubling comment that CBD highlights is 

USGS’s statement that “a careful reading of Amstrup et al (2007) 

[the polar bear status report that formed the basis for the 

Listing Rule] might lead to a different conclusion than that 

reached by the Service.” ARL 101097. USGS goes on:

Taken at face value, the outcomes from the Bayesian 

Network Modeling are that polar bear populations 

living in the Seasonal and Divergent ecoregions are 

most likely extinct within the foreseeable future 

. . . . The fates of the populations living in the 

Convergent and Archipelago ecoregions are different, 

with a much smaller probability of being smaller than 

the present or extinct. The Draft Final Rule does not 

clearly articulate the scientific reasoning behind 

dismissing an “endangered” designation for parts of 

the range . . . . How did the scientific evidence lead 
- 76 -

to the status determination of “threatened” vs 

“endangered”?

ARL 101097 (emphasis added).41

The federal defendants respond that FWS reached a 

reasonable conclusion, even in light of this record evidence. 

The defendants assert that, on balance, the agency found that 

there are no significant morphological or physiological 

differences (i.e., differences in physical form or function) 

among polar bears that indicated physical, evolutionary 

adaptations to environmental differences in the particular 

areas, and that the small genetic differences among polar bears 

in different areas are “not sufficient to distinguish population 

segments.” ARL 117298. According to defendants, the record 

does not show the “marked separation” among either populations 

 41 Plaintiff CBD also points to a 2008 report from Canadian 

polar bear researchers, which concluded that polar bears may be 

appropriately managed in “designatable units.” ARL 127663. The 

Canadian Species at Risk Act (“SARA”), like the ESA, allows for 

the protection of sub-units of species that are genetically 

and/or geographically distinct (so-called “designatable units”

or “DUs”). ARL 127663. The authors of this Canadian study 

noted that “polar bears belong to ecosystems that differ 

fundamentally in their structure and functioning (e.g., sea ice 

regime, biological productivity, prey species and availability, 

etc.). . . . Thus, it appears that, although all polar bears in 

Canada belong to a single species they do not share a single, 

uniform conservation status.” ARL 127668. On this basis, the 

authors recommended analyzing the Canadian polar bear population 

in terms of five distinct genetic units that also represent 

distinct ecological and geographic groups. ARL 127680. 

Plaintiff CBD cites to this study as further evidence that polar 

bear populations are sufficiently distinct to qualify for 

designation as DPS under the ESA. 
- 77 -

or ecoregions that is a pre-requisite for designating a DPS. 

Therefore, the defendants contend, FWS reasonably concluded that 

no polar bear population or ecoregion is “discrete,” applying 

the standards set out in the agency’s DPS Policy. 

3. The Court’s Analysis

Having carefully considered the parties’ arguments and the 

administrative record, the Court finds that it must defer to the 

agency’s application of its DPS Policy. The Court notes that, 

as FWS has acknowledged, there are some recognized differences 

among polar bear ecoregions and even some differences from 

population to population. Each population is apparently

distinguishable enough to be identified as discrete for 

management purposes, and the boundaries of these populations 

have been identified and confirmed over decades of scientific 

study and monitoring. See ARL 139247. Nonetheless, while these 

recognized distinctions would seem to be enough to satisfy the 

minimal criterion that a DPS must be “adequately defined and 

described,” 61 Fed. Reg. at 4724, the Court is not persuaded 

that the agency’s contrary conclusion rises to the level of 

irrationality. 

The Court recognizes that FWS has adopted a formal policy 

for designating a DPS, which was promulgated through notice-andcomment rulemaking and has been expressly upheld as reasonable 

by at least two other courts. Relying on this policy, FWS 
- 78 -

engaged in weighing the facts to determine whether or not any 

polar bear population segment is “markedly separated” from other 

populations. The Court finds that FWS articulated a reasonable 

basis for its conclusion that no polar bear population or 

ecoregion is meaningfully “discrete” for the purposes of DPS 

designation: even if there are behavioral differences among 

polar bear population segments, polar bears are universally 

similar in one crucial respect - namely, their dependence on sea 

ice habitat and negative response to the loss of that habitat. 

The Court must defer to the agency’s reasoned conclusion. See 

Envtl. Def. Fund v. Costle, 657 F.2d at 283.42 Accordingly, the 

 42 Further, the only case law cited by any party on this issue 

weighs in favor of deference to the agency. In an unpublished 

decision, the Ninth Circuit upheld the Service’s finding that 

interior mountain quail are not sufficiently discrete from the 

remainder of the population to warrant listing as a DPS. W. 

Watersheds Project v. Hall, 338 Fed. Appx. 606, 608 (9th Cir. 

2009). Despite significant record evidence showing that the 

mountain quail is geographically and ecologically isolated from 

other quail, the lower court nonetheless upheld the Service’s 

finding that no mountain quail population is “discrete” because 

there is no “physical barrier” that precludes intermixing among 

populations. W. Watersheds Project v. Hall, No. 06-0073, 2007 

U.S. Dist. LEXIS 70710, at *11-13 (D. Idaho 2007). The 

appellate court affirmed the district court’s finding that FWS 

had articulated a rational connection between the facts found 

and the agency’s conclusion that there was no “marked 

separation” among quail populations. W. Watersheds Project, 338 

Fed. Appx. at 608. In that case, both courts upheld the 

Service’s determination as rational, even in the face of 

significant countervailing facts. 
- 79 -

Court concludes that FWS reasonably declined to designate any 

polar bear population or ecoregion as a DPS.43

C. The Service Did Not Arbitrarily Fail to Consider Other 

Listing Factors

Plaintiffs also argue that the Listing Rule should be 

overturned because of deficiencies in the Service’s analysis of 

several of the listing factors the ESA requires the agency to 

consider. First, Joint Plaintiffs contend that FWS arbitrarily 

and capriciously failed to adequately “take into account”

foreign conservation efforts, as required by 16 U.S.C. 

§ 1533(b)(1)(A) (“§ 1553(b)(1)(A)”). Second, Joint Plaintiffs 

contend that FWS arbitrarily and capriciously failed to 

demonstrate that it relied upon the “best available science,”

which is also required by § 1533(b)(1)(A). Third, plaintiff CBD 

contends that FWS arbitrarily and capriciously failed to find 

 43 Plaintiffs CF and SCI assert that because the polar bear 

species is clearly “delimited by international boundaries,” FWS 

should have concluded that polar bear populations are discrete 

on this basis as well. See CF Mot. at 14. In its Listing Rule, 

FWS considered whether international boundaries might satisfy 

the discreteness requirement of the DPS Policy. The agency 

concluded that differences in management across the polar bear’s 

range do not qualify any polar bear population segment as 

“discrete” because each range country shares management 

obligations with other range countries and, therefore, the 

differences in management between polar bear populations are not 

significant. Moreover, the agency noted that any differences in 

management across international boundaries are irrelevant 

because the threat of sea ice loss is a global one that cannot 

be limited to or managed by one country alone. ARL 117298. The 

Court declines to find that this conclusion was irrational.
- 80 -

that overharvest or overutilization is a significant threat to 

polar bear populations (“Listing Factor B”). Finally, Joint 

Plaintiffs contend that FWS arbitrarily and capriciously 

concluded that regulatory mechanisms (both existing and future) 

are insufficient to protect the polar bear despite the threat of 

substantial habitat losses (“Listing Factor D”). Each of these 

claims is addressed in turn.

1. Joint Plaintiffs’ Claim that the Service Failed 

to “Take Into Account” Foreign Conservation 

Efforts to Protect the Polar Bear

The ESA requires that any listing decision must be made 

solely on the basis of the best scientific and 

commercial data available . . . after conducting a 

review of the status of the species and after taking 

into account those efforts, if any, being made by any 

State or foreign nation, or any political subdivision 

of a State or foreign nation, to protect such species, 

whether by predator control, protection of habitat and 

food supply, or other conservation practices, within 

any area under its jurisdiction, or on the high seas.44 

16 U.S.C. § 1533(b)(1)(A) (emphasis added). Joint Plaintiffs 

contend that FWS failed to satisfy this requirement primarily 

because it did not devote a separate section of its Listing Rule 

to an assessment of foreign conservation programs that impact 

polar bears, particularly Canadian sport-hunting programs. 

 44 As the parties acknowledge, Congress did not define the 

phrase “taking into account,” nor has it been defined or 

otherwise clarified by regulation, by agency policy, or by any 

court. 
- 81 -

In its supplemental memorandum, plaintiff CF takes this 

essentially procedural argument a step further. Relying on a 

dictionary definition of the phrase “to take into account,”

plaintiff CF contends that FWS was required not only to 

“consider” but also to “allow for” the existence of foreign 

conservation programs. See CF Mot. at 8. In other words, CF 

contends that FWS is required to ensure that existing 

conservation efforts are not negatively impacted by its listing 

decisions. 

CF contends that Congress specifically intended to 

encourage sport trophy hunting through the ESA. According to 

CF, Congressman John Dingell envisioned this goal when he 

introduced the ESA as a bill in 1973. CF asserts that Rep. 

Dingell described the Act as having been 

carefully drafted to encourage . . . foreign 

governments to develop healthy stocks of animals 

occurring naturally within their borders. If these 

animals are considered valuable as trophy animals 

. . . they should be regarded as a potential source of 

revenue to the managing agency and they should be 

encouraged to develop to the maximum extent compatible 

with the ecosystem upon which they depend. 

CF Mot. at 10 (citing ARL 152657). Further, CF asserts that the 

House of Representatives “clearly elucidated its intent” when it 

explained:

[T]he section requires the Secretary to give full 

consideration to efforts being currently made by any 

foreign country to protect fish or wildlife species 

within that country, in making a determination as to 
- 82 -

whether or not those species are endangered or 

threatened. There is provided ample authority and 

direction to the Secretary to consider the efforts of 

such countries in encouraging the maintenance of 

stocks of animals for purposes such as trophy hunting. 

CF Mot. at 9 (citing H. Rep. No. 93-412, at 150 (1973)). CF 

contends that this passage represents a consensus on the 

agency’s “obligation to support the use of trophy hunting to 

pursue conservation goals.” CF Mot. at 9.45 

The federal defendants generally respond that FWS 

adequately “took into account” the conservation efforts being 

made in the polar bear range countries - both regulatory and 

non-regulatory - and concluded that none of those efforts 

offsets or significantly reduces the primary threat to the polar 

bear’s survival: loss of sea ice habitat. See Fed. Def. Mot. at 

142 (citing ARL 117246). According to the defendants, this is 

all the ESA requires. 

 45 According to CF, its reading of the ESA also makes sense 

because trophy hunting programs are essential to the efficacy of 

the statute. These programs purportedly provide a useful lever 

by which the United States can exercise its influence to 

accomplish conservation goals in countries that are beyond the 

ESA’s reach. Specifically, CF contends that the United States 

can encourage a foreign country to comply with ESA conservation 

standards (and thus protect a species that is endangered outside 

our borders) by threatening the country with import 

restrictions, so long as that country has an economically 

valuable and viable trophy hunting program. CF contends that 

Congress intended to use trade to manage the actions of foreign 

individuals and nations in this way. Therefore, CF concludes, 

all listing decisions must take foreign programs into account by 

ensuring that those programs remain an effective tool for 

furthering conservation goals.
- 83 -

Having carefully considered the parties’ arguments and the 

administrative record, this Court agrees with the federal 

defendants. Although an explicit finding might have been 

clearer, the Court is satisfied that FWS sufficiently considered 

conservation efforts in the polar bear range countries before it 

decided to list the polar bear as threatened range-wide. As 

part of its analysis of Listing Factor B, the agency discussed

harvest management programs in each of the range countries, 

along with the relevant conservation benefits of those programs. 

FWS also addressed the conservation and economic benefits of 

polar bear sport-hunting programs in its response to comments on 

the Listing Rule. See ARL 117240. As part of its analysis of 

Listing Factor D, the agency enumerated the regulatory 

mechanisms that govern polar bears in each of the range 

countries - including legal protections and on-the-ground 

habitat protections - as well as bilateral and multilateral 

agreements and overarching international frameworks that govern 

management of the polar bear range-wide, such as the 1973 

Agreement on the Conservation of Polar Bears and the Convention 

on International Trade in Endangered Species (“CITES”). See ARL 

117285-92. Beyond sport-hunting programs and regulatory 

mechanisms, FWS also considered voluntary agreements between 

indigenous peoples for jointly managing polar bear populations, 
- 84 -

national parks and nature reserves, and a variety of other 

foreign conservation efforts. 

Joint Plaintiffs have not identified a single foreign 

conservation effort that FWS failed to take into account. 

Indeed, Joint Plaintiffs have not even explained why the 

agency’s exhaustive analysis is deficient, except to say that 

the agency did not expressly state that it was taking foreign 

conservation efforts “into account.” The Court declines to 

invalidate the Listing Rule on this basis. 

The Court also rejects plaintiff CF’s related claim that 

the agency was obligated to avoid making a listing decision for 

the polar bear that would negatively impact sport-hunting

programs. Although CF has cited some isolated passages from the 

legislative history that express support for trophy hunting 

programs, neither the statute itself nor its legislative history 

makes clear that the ESA requires FWS to avoid making listing 

decisions that might affect those programs.46 Rather, the ESA 

 46 In fact, the Court notes that in the quote from Congressman 

Dingell that plaintiff CF frequently cites for support, 

plaintiff repeatedly and disingenuously omits key language. In 

full, this quote reads: “If these animals are considered 

valuable as trophy animals and they are not endangered they 

should be regarded as a potential source of revenue to the 

management agency[.]” Comm. on Env’t and Public Works, 97th 

Cong., A Legislative History of the Endangered Species Act of 

1973, as Amended in 1976, 1977, 1978, and 1981, at 195 (1982) 

(emphasis added). This statement would suggest that the agency 

may promote trophy hunting programs only to the extent that 

those programs do not impact a listed species.
- 85 -

only requires the agency to consider how foreign conservation 

efforts might impact the decision to list a particular species 

as threatened or endangered. See 16 U.S.C. § 1533(b)(1)(A) 

(requiring the Secretary to make listing decisions “solely on 

the basis of the best scientific and commercial data available

. . . after taking into account those efforts, if any, being 

made by any State or foreign nation, or any political 

subdivision of a State or foreign nation, to protect such 

species, whether by predator control, protection of habitat and 

food supply, or other conservation practices, within any area 

under its jurisdiction, or on the high seas.”).47 That is 

 47 Similarly, the 1973 House Report cited by plaintiff CF 

states that ESA Section 4(b) “requires the Secretary to give 

full consideration to efforts being currently made by any 

foreign country to protect fish or wildlife species within the 

country, in making a determination as to whether or not those 

species are endangered or threatened.” H. Rep. No. 93-412, at 

11 (1973) (emphasis added). The Court notes that this is the 

same interpretation adopted by FWS in its “Policy for Evaluation 

of Conservation Efforts When Making Listing Decisions” (“PECE 

Policy”), which specifies the conditions under which FWS may 

consider conservation efforts that have not yet been 

implemented. 68 Fed. Reg. 15,100, 15,100 (March 28, 

2003)(“While the Act requires us to take into account all 

conservation efforts being made to protect a species, the policy 

identifies criteria we will use in determining whether 

formalized conservation efforts that have yet to be implemented 

or to show effectiveness contribute to making listing a species 

as threatened or endangered unnecessary.” (emphasis added)). 

This is also the very same interpretation set out in those 

listing decisions that Joint Plaintiffs cite as examples of 

where the agency properly took foreign conservation programs 

into account. Proposed Status for DPS of Rockfish in Puget 

Sound, 74 Fed. Reg. 18,516, 18,537 (Apr. 23, 2009) (“Section 

4(b)(1)(A) of the ESA requires the Secretary of Commerce to take 
- 86 -

exactly what FWS did here. After considering a variety of 

foreign conservation efforts, FWS concluded that, while these 

efforts may have been sufficient to protect the species from 

overharvest and disturbance, they will not be sufficient to 

offset sea ice loss, which is the primary threat to the polar 

bear’s survival, and thus these efforts did not affect the 

agency’s conclusion that the polar bear warranted listing under 

the ESA. See ARL 117292. This is all the statute requires. 

Accordingly, the Court concludes that the agency properly 

discharged its duty under § 1533(b)(1)(A) to take foreign 

conservation programs into account. 

2. Joint Plaintiffs’ Claim that the Service Failed 

to Rely upon the “Best Available Science”

Joint Plaintiffs argue that FWS also failed to demonstrate 

that it relied upon the “best scientific and commercial data 

available,” as required by § 1533(b)(1)(A). Joint Plaintiffs 

put forward the following three arguments in support of this 

claim: First, they contend that climate change science and 

 

into account efforts being made to protect a species that has 

been petitioned for listing. Accordingly, we will assess 

conservation measures being taken to protect these six rockfish 

DPSs to determine whether they ameliorate the species’

extinction risks.” (emphasis added)); Status Determination for 

the Gulf of Maine DPS of Atlantic Salmon, 74 Fed. Reg. 29,344, 

29,377 (June 19, 2009) (“We then assess existing efforts being 

made to protect the species to determine if these conservation 

efforts improve the status of the species such that it does not 

meet the ESA’s definition of a threatened or endangered 

species.” (emphasis added)).
- 87 -

predictions related to sea ice loss at the time the agency made 

its listing decision were too uncertain to support the agency’s 

conclusion that polar bears are threatened. Second, they point 

to weaknesses in the carrying capacity and Bayesian Network 

models developed by USGS and claim that these models were 

likewise insufficient to support the agency’s listing 

determination. Third, and finally, Joint Plaintiffs assert that 

FWS ignored all but five years of data for the Southern Beaufort 

Sea polar bear population and drew improper scientific 

conclusions from this limited data set. The Court will address

each of these arguments in turn. 

a. Joint Plaintiffs’ Argument that Climate 

Science Is Too Uncertain to Support the 

Service’s Conclusion 

First, Joint Plaintiffs contend that the polar bear did not 

warrant listing under the ESA at the time of listing because the 

administrative record shows “tremendous uncertainty” about the 

nature and extent of future global climate change and the impact 

of any such change on the Arctic ecosystem and on the polar 

bear. JP Mot. at 17. Specifically, Joint Plaintiffs point to a 

2007 “Uncertainty Report” from the administrative record, which 

notes that “uncertainty in projections of Arctic climate change 

is relatively high” as a consequence of its smaller spatial 

scale and high sensitivity to climate change impacts and the 

complex processes that control ice development. See JP Mot. at 
- 88 -

18 (citing ARL 128805). Further, Joint Plaintiffs note that the 

IPCC reports themselves, which are widely acknowledged to be the 

definitive source of modern climate change knowledge, indicate

that complex systems like the Arctic are “inherently 

unpredictable” and have “high scientific uncertainties,” which 

range from “inadequate scientific understanding of the problem, 

data gaps and general lack of data to inherent uncertainties of 

future events in general.” JP Mot. at 19 (citing IPCC’s Special 

Report on Emissions Scenarios Section 1.2, Box 1-1: 

Uncertainties and Scenario Analysis, http://grida.no/climate/

ipcc/emission/025.htm). This inherent uncertainty, according to 

Joint Plaintiffs, is compounded by the predictive nature of the 

USGS forecasting reports, which attempt to forecast sea ice 

conditions up to 100 years into the future on the basis of 

mathematical modeling that cannot replicate the complex Arctic 

system. 

Joint Plaintiffs contend that FWS failed to explain how,

despite the high degree of uncertainty in climate science, it 

nonetheless found that polar bears are “likely” to be in danger 

of extinction within the foreseeable future.48 According to 

 48 As discussed above, according to Joint Plaintiffs, the 

proper standard for determining whether the polar bear is 

“likely” to become endangered is 67-90% likelihood. However, as 

the Court has concluded, FWS did not adopt such a high standard 

and thus need not demonstrate that it met that high standard. 
- 89 -

Joint Plaintiffs, the uncertainty surrounding future climate 

change impacts should have prevented FWS from being able to 

discern any such trend with confidence. JP Mot. at 20-21

(citing Bennett v. Spear, 520 U.S. 154, 176 (1997) (“The obvious 

purpose of the requirement that each agency ‘use the best 

scientific and commercial data available’ is to ensure that the 

ESA not be implemented haphazardly, on the basis of speculation 

or surmise.”)). 

The federal defendants respond that Joint Plaintiffs’ 

arguments must fail as a matter of law because they incorrectly 

assume that scientific certainty (or even a “high degree” of 

certainty) is required before the Service may list a species as 

threatened under the ESA. The federal defendants point out that 

Joint Plaintiffs have neither challenged the IPCC reports 

directly nor identified better climate change data. Joint 

Plaintiffs merely assert that the available climate science at 

the time of listing was “too uncertain” for the Service to rely 

upon, a position which the federal defendants contend is 

contrary to D.C. Circuit precedent. See Sw. Ctr. for Biological 

Diversity v. Babbitt, 215 F. 3d 58, 60 (D.C. Cir. 2000) (finding 

that the Service is required to rely on the best available 

scientific data, even if that data is “quite inconclusive”). 

The federal defendants further respond that Joint 

Plaintiffs have overstated the uncertainty of climate change 
- 90 -

science. According to the federal defendants, mainstream 

climate science at the time of listing, as reflected in the IPCC 

AR4, accepted that further global and regional Arctic warming is 

very likely to occur, based on the levels of greenhouse gases in 

the atmosphere and those likely to be emitted. See Fed. Def. 

Mot. at 81 (citing ARL 152436; ARL 151205). Moreover, the 

federal defendants contend that FWS found that any uncertainty 

in climate change projections could be reduced by considering an 

“ensemble” of climate change models – in other words, by 

averaging the results of a group of models that most closely 

reflect actual observed conditions – and it did so here. See 

Fed. Def. Mot. at 81 (citing ARL 117232; ARL 128806). According 

to the federal defendants, uncertainties surrounding climate 

change impacts did not prevent the Service from making a 

credible assessment of the likely direction and magnitude of 

those impacts, even if it was not possible to make such 

predictions with precision. 

Having considered the parties’ arguments, the Court agrees 

with the federal defendants. Joint Plaintiffs’ claim boils down 

to an argument that the available data were not certain enough 

to adequately support the outcome of the agency’s listing 

decision for the polar bear. It is well-settled in the D.C. 

Circuit that FWS is entitled - and, indeed, required - to rely 

upon the best available science, even if that science is 
- 91 -

uncertain or even “quite inconclusive.” Sw. Ctr. for Biological 

Diversity, 215 F. 3d at 60. The “best available science”

requirement merely prohibits FWS from disregarding available 

scientific evidence that is better than the evidence it relied 

upon. Id. (citing City of Las Vegas v. Lujan, 891 F.2d 927, 933 

(D.C. Cir. 1989)); see also Building Indus. Ass’n of Superior 

Cal. v. Norton, 247 F.3d 1241, 1246 (D.C. Cir. 2001) (“Assuming 

the studies the Service relied on were imperfect, that alone is 

insufficient to undermine those authorities’ status as the ‘best 

scientific . . . data available’ . . . . [T]he Service must 

utilize the ‘best scientific . . . data available,’ not the best 

scientific data possible.”). Joint Plaintiffs have pointed to 

no information that was superior to the IPCC AR4 reports at the 

time the agency made its listing decision. The Court declines 

to find that it was arbitrary for the agency to rely upon what 

were generally accepted to be the best available climate change 

data at the time the agency made its listing decision, 

particularly when the agency also took steps to reduce 

uncertainty to the extent feasible.

Moreover, an agency is entitled to particular deference 

where it has drawn conclusions from scientific data. Ethyl 

Corp., 541 F.2d at 36. As this Court has observed, “some degree 

of speculation and uncertainty is inherent in agency 

decisionmaking” and “though the ESA should not be implemented 
- 92 -

‘haphazardly’ . . . an agency need not stop in its tracks when 

it lacks sufficient information.” Oceana v. Evans, 384 F. Supp. 

2d 203, 219 (D.D.C. 2005) (citing cases). Notwithstanding a 

handful of references to uncertainty that appear in record 

documents, Joint Plaintiffs have failed to persuade this Court 

that FWS implemented the ESA “haphazardly.” Accordingly, the 

Court concludes that FWS did not act arbitrarily in relying on 

and drawing reasonable conclusions from the IPCC reports and

climate models in making its listing determination for the polar 

bear. 

b. Joint Plaintiffs’ Argument that the USGS 

Population Models Do Not Support the 

Service’s Conclusion 

Second, Joint Plaintiffs contend that FWS similarly failed 

to demonstrate a rational connection between the USGS population 

models and the conclusions that the agency drew from those 

models. Specifically, Joint Plaintiffs assert (i) that the two 

USGS population models FWS considered - the carrying capacity 

and Bayesian Network models – are fundamentally flawed, (ii) 

that FWS failed to address the shortcomings of both models in 

its Listing Rule, and (iii) that the agency also failed to 

explain how these models sufficiently support its listing 

decision. 

Joint Plaintiffs identify two primary flaws with the 

carrying capacity model: first, that the term “carrying 
- 93 -

capacity” is misleading because USGS did not use the term 

according to its traditional definition,49 and second, that the 

model improperly assumes that current estimated polar bear 

densities will remain constant through time, an assumption which 

USGS itself admitted is “‘almost certainly not valid.’” See JP 

Mot. at 28 (quoting ARL 82463). As a result, Joint Plaintiffs 

contend that the carrying capacity model gives a false 

impression that every unit change in sea ice habitat will result 

in a corresponding unit change in polar bear population numbers. 

With regard to the Bayesian Network model, Joint Plaintiffs 

point out that the model was only at a preliminary stage at the 

time of listing because it was developed based on the input of 

only one polar bear expert and, therefore, requires further 

development before it can be considered reliable. 

As an initial matter, the federal defendants respond that 

Joint Plaintiffs focus too narrowly on the weaknesses of these 

two models. These models were not the sole basis for the 

agency’s listing decision; rather, the federal defendants 

contend that FWS merely found that these two models were 

consistent with the other record evidence before it, including 

published literature and the opinions of numerous peer 

 49 The traditional definition of the term “carrying capacity”

refers to “[t]he maximum number of individuals that a given 

environment can support without detrimental effects.” JP Mot. 

at 28 (quoting American Heritage Dictionary of the English 

Language (4th ed. 2009)).
- 94 -

reviewers. As a legal matter, the federal defendants note, the 

question is not whether these two models alone support the 

agency’s decision but instead whether the agency’s decision is 

supported by the record as a whole. See Fed. Def. Mot. at 85 

(citing Van Valin v. Locke, 671 F. Supp. 2d 1, 8 (D.D.C. 2009)). 

Here, according to the federal defendants, the full record 

adequately supports the agency’s listing decision. 

In any event, the federal defendants contend that FWS fully 

disclosed the weaknesses in both models and discounted them 

accordingly by relying only upon their general direction and 

magnitude and that FWS was entitled to draw reasonable 

conclusions from the USGS population models, despite their 

acknowledged flaws. According to the federal defendants, these

models were the best available scientific information of their 

kind when FWS made its listing decision, and the law requires

the agency to consider them. Fed. Def. Mot. at 87 (citing 

Building Indus. Ass’n, 247 F.3d at 1246). The federal 

defendants further note that it is well-settled that an expert 

agency has wide latitude to consider and weigh scientific data 

and information within its area of expertise. Fed. Def. Mot. at 

90 (citing Am. Bioscience v. Thompson, 269 F.3d 1077, 1083 (D.C. 

Cir. 2001)). 

Having considered the parties’ arguments, the Court 

concludes that Joint Plaintiffs’ second argument must also fail. 
- 95 -

Despite plaintiffs’ criticisms, they have not, in fact,

challenged the USGS models as the best available science of 

their kind at the time of listing. Instead, Joint Plaintiffs 

appear to take the position that FWS should have drawn different 

conclusions from these models or, indeed, disregarded them 

entirely. The Court cannot agree. 

Again, it is well-settled in the D.C. Circuit that an 

agency must rely upon the best available science, even if that 

science is imperfect. See Building Indus. Ass’n, 247 F.3d at 

1246.50 Moreover, Joint Plaintiffs have failed to demonstrate 

that FWS drew wholly arbitrary conclusions from the USGS 

population models. As this Court has observed, “[t]here is 

nothing inherently problematic about using predictions of 

population trends to analyze the status of a species. . . .” 

Oceana, Inc. v. Evans, 384 F. Supp. 2d 203, 221 n.21 (D.D.C. 

2005). FWS candidly acknowledged the weaknesses in both models 

and tempered its reliance on them accordingly, as it is 

 50 The Court notes, further, that although the “best available 

science” mandate does not require FWS to generate new scientific 

data, see Sw. Ctr. for Biological Diversity v. Babbitt, 215 F.3d 

59, 60-61 (D.C. Cir. 2000), FWS essentially did so here when it 

commissioned USGS to conduct additional analysis, including 

these population models. The federal defendants point out that 

population modeling data is not required for a listing decision 

and in many cases this type of data is not available. See Fed. 

Def. Reply at 49, n.22. The Court declines to find that it was 

irrational for FWS to consider available population models, even 

if they were imperfect. 
- 96 -

permitted to do in weighing scientific information. See Balt. 

Gas & Elec. Co. v. Natural Res. Def. Council, 462 U.S. 87, 103 

(1983) (noting that a reviewing court must be “at its most 

deferential” when examining conclusions made “at the frontiers 

of science”); see also Int'l Fabricare Inst. v. EPA, 972 F.2d 

384, 389 (D.C. Cir. 1992) (“The rationale for deference is 

particularly strong when the [agency] is evaluating scientific 

data within its technical expertise: ‘[I]n an area characterized 

by scientific and technological uncertainty[,] . . . this court 

must proceed with particular caution, avoiding all temptation to 

direct the agency in a choice between rational alternatives.’”

(quoting Envtl. Def. Fund v. Costle, 578 F.2d 337, 339 (D.C. 

Cir. 1978))).51 Given the deference courts must grant to an 

 51 In their opening brief, Joint Plaintiffs argue that the FWS 

improperly relied upon the USGS population models because these 

models bear no “rational relationship” to the reality that they

are purported to represent. JP Mot. at 27 (citing Greater 

Yellowstone Coal. v. Kempthorne, 577 F. Supp. 2d 183, 198 

(D.D.C. 2008) (“[A] model must be rejected as arbitrary and 

capricious ‘if there is simply no rational relationship between 

the model and the known behavior of [the items] to which it is 

applied.’”) (internal citation omitted)). In their reply brief, 

however, Joint Plaintiffs clarify that they do not challenge the 

agency’s choice of models; rather, they challenge the Service’s 

application of those models. See JP Reply at 36. To the extent 

Joint Plaintiffs have challenged the Service’s choice of models, 

they have failed to show that the carrying capacity and Bayesian 

Network models are not “rationally related” to the reality they 

purport to represent, and as such their citation to Greater 

Yellowstone Coalition is inapt. In Greater Yellowstone 

Coalition, this Court rejected sound level modeling that was at 

odds with recorded sound levels and that formed the exclusive 

basis for the agency’s snowmobile plan. 577 F. Supp. 2d at 198-
- 97 -

agency in this area, this Court declines to find that the 

agency’s reliance on and evaluation of the USGS population 

models was arbitrary and capricious. 

c. Joint Plaintiffs’ Argument that the Service

Ignored Scientific Data and Made Improper 

Findings Regarding the Southern Beaufort Sea 

Population

As noted above, in its Listing Rule FWS relied in part on 

long-term studies of the Southern Beaufort Sea population as 

evidence suggesting that polar bears experience nutritional 

stress as a result of sea ice loss. Joint Plaintiffs challenge 

the Service’s specific findings as to the Southern Beaufort Sea 

population. Joint Plaintiffs raise three arguments: (1) that 

FWS improperly concluded that the Southern Beaufort Sea polar 

bear population had experienced population declines as a result 

of diminishing sea ice at the time of listing; (2) that FWS 

ignored all but five years of data when it reached this 

conclusion; and (3) that record evidence does not, in fact, show 

declines in polar bear vital rates and reproductive success in 

the Southern Beaufort Sea population. In particular, Joint 

Plaintiffs point to two studies – Hunter, et al. (2007) (ARL 

82291-341) and Regehr, et al. (2007) (ARL 131467-516) – which 

purportedly demonstrate, based on data from as early as 1979,

 

99. Here, the Court is persuaded that the projections of the 

USGS population models are generally consistent with observed 

facts about sea ice decline and its impacts on polar bears at 

the time of listing. 
- 98 -

that FWS overstated the significance of the past trend in the 

number of ice-free days per year in the Southern Beaufort Sea. 

The federal defendants respond, first, that Joint 

Plaintiffs misstate the agency’s actual finding with regard to 

the Southern Beaufort Sea polar bear population. According to 

the federal defendants, FWS did not, in fact, find that the 

Southern Beaufort Sea population had experienced statisticallysignificant population declines at the time the agency made its 

listing determination.52 Instead, the agency relied upon 

modeling and related data indicating a significant future

decline in polar bear numbers in that population. See Fed. Def. 

Mot. at 96. According to the federal defendants, this 

significant future decline adequately supports the agency’s 

conclusion based on the record as a whole that the polar bear 

qualified for threatened status at the time of listing, both in 

the Southern Beaufort Sea and throughout its range.

Second, the federal defendants respond that FWS did not 

ignore past data related to the Southern Beaufort Sea polar bear 

population. Indeed, the federal defendants point out that FWS 

explicitly considered both of the studies identified by Joint 

Plaintiffs in its Listing Rule. See ARL 117248, 117272. 

 52 Indeed, FWS found that there was not a statisticallysignificant decline in polar bear numbers in the Southern 

Beaufort Sea from 1986-2006 based upon the available data. See 

ARL 117272. 
- 99 -

However, according to the federal defendants, the agency 

determined that the best available data at the time of listing 

was one five-year study that directly compared the number of 

ice-free days in the Southern Beaufort Sea to the population 

growth rate among polar bears in that area. See Fed. Def. Mot. 

at 98. As the federal defendants note, Joint Plaintiffs have 

identified no other studies that make that same direct 

comparison over a larger data set. Therefore, although the 

agency, like Joint Plaintiffs, would have preferred more data, 

the federal defendants contend that this five-year study was the 

“‘most comprehensive and complete’” data of its kind and, as 

such, FWS properly relied upon it. Fed. Def. Mot. at 98

(quoting ARL 110135). 

Finally, the federal defendants reject Joint Plaintiffs’ 

argument that no declines in vital rates had been observed in 

the Southern Beaufort Sea prior to listing. They respond that 

researchers studying this population found that a number of 

measures of polar bear physical condition and reproductive 

success had declined prior to the agency’s listing 

determination. For example, the federal defendants assert that 

in a study covering the period of 1982-2006, USGS scientists 

determined that mass, length, and skull sizes of young males had 

declined; mass, length, and skull sizes of young females had 

declined; skull sizes and/or lengths of adult males and females 
- 100 -

had declined; and the number of yearling cubs per female had 

declined, suggesting reduced cub survival. See Fed. Def. Mot. 

at 98-99 (citing ARL 117272-73; ARL 82418, 82429-30). To the 

extent Joint Plaintiffs disagree with the evidence FWS 

considered, the federal defendants respond that FWS is the 

expert finder of fact and was permitted to draw reasonable 

conclusions about “equivocal evidence.” Fed. Def. Mot. at 99-

100 (citing Animal Legal Def. Fund, 204 F.3d at 235). 

Largely for the reasons given by the federal defendants and 

based upon the standards it has already articulated, the Court 

is persuaded that Joint Plaintiffs’ final argument must fail as 

well. Joint Plaintiffs have simply not met the very high burden 

of showing that the conclusions that the agency drew from the 

best available scientific information for the Southern Beaufort 

Sea population were arbitrary and capricious.53

 53 Although plaintiff CBD generally agrees that FWS relied on 

the best available science in reaching its listing determination 

for the polar bear, it has raised a related issue: whether FWS 

is required to give the “benefit of the doubt to the species” in 

drawing conclusions based on the best available scientific 

information. See CBD Mot. at 3 (citing Center for Biological 

Diversity v. Lohn, 295 F. Supp. 2d 1223, 1239 (W.D. Wash. 

2003)); see also Conner v. Burford, 848 F.2d 1441, 1454 (9th 

Cir. 1988). Defendant-Intervenor AOGA and the federal 

defendants disagree that this standard applies in a listing 

case. The Court finds that it need not decide that question

because this case does not resemble any of the cases where 

courts have chosen to apply the “benefit of the doubt” standard. 

See Conner, 848 F.2d at 1454 (FWS failed to rely on the best 

available science in reaching a jeopardy determination); Ctr. 

for Biological Diversity v. Lohn, 296 F. Supp. 2d 1223, 1239 
- 101 -

3. Plaintiff CBD’s Claim that the Service Failed to 

Consider Whether the Threat of Overutilization 

Warranted Listing the Polar Bear As Endangered 

(“Listing Factor B”)

As discussed throughout, the ESA requires FWS to list a 

species on the basis of one or more of the following five 

criteria or “listing factors”: 

(a) the present or threatened destruction, 

modification, or curtailment of the species’ 

habitat or range;

(b) overutilization for commercial, recreational, 

scientific, or educational purposes;

(c) disease or predation;

(d) the inadequacy of existing regulatory mechanisms; 

or

(e) other natural or manmade factors affecting the 

species’ continued existence.

16 U.S.C. § 1533(a)(1). In this case, FWS determined, based 

upon the record before it, that the polar bear is threatened 

throughout its range solely based upon Listing Factor A, the 

present or threatened destruction of the species’ habitat. 

Plaintiff CBD contends that FWS downplayed the equally severe 

 

(W.D. Wash. 2003) (FWS failed to rely on the best available 

science when it refused to list the orca), vacated and remanded 

on other grounds, 483 F.3d 984 (9th Cir. 2007); Defenders of 

Wildlife v. Babbitt, 958 F. Supp. 670, 680-81 (D.D.C. 1997) (FWS 

failed to rely upon the best available science when it refused 

to list the Canada Lynx). Here, the Court finds that FWS 

properly relied upon the best available scientific information 

for the polar bear when it decided to list the polar bear as 

threatened range-wide. CBD has cited no instance where a court 

has found that the Service was required to list a threatened 

species as endangered based on the “benefit of the doubt” 

standard, nor is the Court aware of any such authority. 
- 102 -

threat of hunting to the polar bear and, consequently, failed to 

adequately consider Listing Factor B, overutilization. 

Specifically, plaintiff CBD asserts that FWS was wrong to 

conclude that overutilization does not “by itself” pose a 

sufficient threat to justify listing the species. CBD Mot. at 

45. As a threshold matter, according to CBD, this standard 

improperly raises the bar for listing because the ESA requires 

FWS to analyze whether the threat of overharvest in combination 

with the threat of global warming renders the polar bear 

currently in danger of extinction. Moreover, CBD contends that 

the Service’s conclusion does not follow from the available 

evidence. In support of this argument, CBD cites to statements 

in the record indicating that FWS scientists believe overharvest 

is a threat to the species, as well as statements from the 

Listing Rule itself indicating that five polar bear populations 

may have been harvested at unsustainable levels, based upon 

anecdotal evidence. See CBD Mot. at 41-43. Finally, plaintiff 

CBD asserts that FWS inappropriately relied upon uncertain 

future management actions when it concluded that current 

management mechanisms are “‘flexible enough to allow adjustments 

in order to ensure that harvests are sustainable.’” CBD Mot. at 

44 (quoting ARL 117284). 

The federal defendants generally respond that FWS took

harvest rates into account, among other factors, when it 
- 103 -

considered whether any of the polar bear populations was 

endangered. On the basis of this analysis, FWS concluded that 

polar bear harvests may approach unsustainable levels in the 

future, as polar bears begin to experience more nutritional 

stress and declining population numbers. The federal defendants 

maintain that the agency’s analysis, as well as its reasoned 

conclusion, did not contravene the ESA. Moreover, because FWS

found that the polar bear is primarily threatened by habitat 

loss, the defendants assert that it is essentially a moot point 

whether the species is also threatened based on overutilization. 

Having carefully considered the parties’ arguments and the 

administrative record, the Court is not persuaded that either 

the agency’s analysis or its conclusion on this issue was 

arbitrary, capricious, or contrary to law. As an initial 

matter, to the extent FWS may have erred when it determined that 

harvest is not “by itself” a sufficient basis for listing the 

polar bear as threatened, the Court finds that this error would 

not be a sufficient basis for invalidating the Listing Rule. 

The ESA is clear that a species may be listed based on “any one”

of the five listing factors. 16 U.S.C. § 1533(a)(1). Here, FWS 

reasonably determined that the polar bear qualified for 

threatened status range-wide based on habitat loss (“Listing 

Factor A”) alone. 
- 104 -

The relevant question, however, is whether FWS unreasonably 

concluded that the polar bear was not endangered at the time of 

listing, taking the threat of future habitat losses in 

combination with any threat of overharvest. The Court concurs 

with plaintiff CBD that the agency’s own regulations require FWS 

to list a species if “any one or a combination” of the five 

listing factors demonstrates that it is threatened or 

endangered. 50 C.F.R. § 424.11(c) (emphasis added); see also 

Wildearth Guardians v. Salazar, 741 F. Supp. 2d 89, 103 (D.D.C. 

2010) (finding that the Service’s failure to consider cumulative 

impact of listing factors rendered the agency’s decision not to 

reclassify the Utah prairie dog arbitrary and capricious). 

Nonetheless, the Court finds that FWS did consider whether the 

threat of overharvest might impact the polar bear in conjunction 

with projected habitat losses. 

Specifically, the agency found that harvest “is likely 

exacerbating the effects of habitat loss in several 

populations,” and that polar bear mortality from harvest “may in 

the future approach unsustainable levels for several 

populations” as these populations begin to experience the 

stresses of habitat change. ARL 117284. FWS concluded, 

however, that the polar bear was not in danger of extinction on 

this basis at the time of listing and, moreover, that harvest 

regulations, where they exist, are “flexible enough to allow 
- 105 -

adjustments in order to ensure that harvests are sustainable.”

ARL 117284. Even if the evidence cited by plaintiff CBD 

persuasively demonstrates that overharvest was a threat to the 

polar bear at the time of listing, the Court is not persuaded 

that this evidence demonstrates that the agency’s conclusion was 

an irrational one. 

Moreover, the Court is not persuaded that FWS

inappropriately relied upon uncertain future management actions 

when it reached this conclusion. FWS expressly considered only 

existing mechanisms in making its listing determination for the 

polar bear. ARL 117284 (“[I]n making our finding we have not 

relied on agreements that have not been implemented.”). As 

documented in the Listing Rule, most polar bear range countries 

have regulatory mechanisms in place that address polar bear 

hunting. See ARL 117284. The Listing Rule indicates that, 

while overharvest could be occurring in approximately five 

populations for which no data were available at the time of 

listing, see ARL 117282, hunting was below maximum sustainable 

levels in all populations for which data were available, see ARL 

117283, Table 2. FWS concluded therefore that existing 

mechanisms to control overharvest had been generally 

demonstrated to be effective and, moreover, that effective 

management of hunting will continue to be important to “minimize 

effects for populations experiencing increased stress.” ARL 
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117283. The Court declines to find, in the absence of clear 

evidence to the contrary, that it was arbitrary for the agency 

to assume that the adaptive management principles, which appear 

to be working for the majority of polar bear populations, will 

continue to be flexible enough to account for future population 

reductions.54

Accordingly, the Court concludes that FWS articulated a 

rational basis for its determination that the polar bear was not 

in danger of extinction at the time of listing because of the 

threat of anticipated sea ice losses, even taking into account

potential threats from overharvest.

4. Joint Plaintiffs’ Claim that the Service Wrongly 

Concluded that Existing Regulatory Mechanisms 

Will Not Protect Polar Bears despite Anticipated 

Habitat Losses (“Listing Factor D”)

Joint Plaintiffs argue, finally, that FWS drew an improper 

conclusion from the evidence when it found that existing 

regulatory mechanisms are not sufficient to protect polar bears 

despite anticipated sea ice losses. According to Joint 

Plaintiffs, even if there are no regulatory mechanisms that 

would “eradicate” the threat of sea ice loss, existing 

regulatory mechanisms such as conservation plans and other 

 54 To the extent CBD further contends that FWS failed to 

consider the impacts of illegal hunting, the Court is persuaded 

that FWS took illegal hunting into account to the extent 

feasible. See ARL 117245-46; ARL 117284. 
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federal, state, and foreign laws are not necessarily 

insufficient to protect a “viable population” of bears over the 

foreseeable future.55 JP Mot. at 22. Given that overall polar 

bear population numbers had risen in the years prior to listing, 

Joint Plaintiffs assert that existing regulatory mechanisms were 

not only adequate to protect the species at the time of listing 

but they will continue to adequately protect the species into 

the future. 

The federal defendants respond that FWS rationally 

concluded that existing regulatory mechanisms at the time of 

listing will be inadequate to protect the polar bear despite

future habitat losses. The defendants explain that, while the 

agency found that existing regulatory mechanisms had adequately 

addressed previous threats to the polar bear (e.g., overhunting) 

 55 Joint Plaintiffs have also argued that FWS unlawfully 

failed to establish either a “minimum viable population” size or 

to determine the “minimum amount of habitat” necessary to 

“support a viable population.” JP Mot. at 32. At least two 

circuits have rejected similar arguments. See Home Builders 

Ass’n of N. Cal. v. U.S. FWS, 321 Fed. Appx. 704, 705 (9th Cir. 

2009) (“The FWS is not required to state a threshold level of 

habitat loss that is necessary to find a species is 

threatened.”); Heartwood v. Kempthorne, No. 05-313, 2007 U.S. 

Dist. LEXIS at *27 (S.D. Ohio June 19, 2007) (rejecting the 

argument that FWS was required to “identify a number that 

represents the point at which the Indiana bat will survive, a 

number that represents the point at which the Indiana bat will 

recover, and a number that represents the point at which the 

total population will become extinct”), aff’d, 302 Fed. Appx. 

394 (6th Cir. 2008). This Court concurs with those courts that 

the ESA itself articulates the appropriate standard for listing, 

which is limited to the five factors outlined in 16 U.S.C. 

§ 1533. Accordingly, Joint Plaintiffs’ related claim must fail.
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and presumably will remain adequate to protect against those 

threats, there is no evidence in the record that these existing 

regulatory mechanisms are sufficient to ensure that polar bears 

will not become in danger of extinction within the foreseeable 

future. 

The Court declines to find that FWS improperly concluded 

that existing regulatory mechanisms are inadequate to protect 

the polar bear. Joint Plaintiffs have pointed to no record 

evidence suggesting that existing mechanisms will offset the 

potential impacts to the polar bear from significant future

losses of its sea ice habitat. Therefore, plaintiffs have given 

the Court very little basis from which to conclude that the 

agency’s finding was irrational, arbitrary and capricious; 

accordingly, the Court declines to overturn the agency’s 

reasoned determination on these grounds.56

 56 In a related claim, plaintiff SCI argues that FWS also 

failed to consider whether future regulatory and non-regulatory 

mechanisms would substantially mitigate the threat of sea ice 

loss. Although SCI concedes that Listing Factor D only requires 

FWS to consider the inadequacy of “existing” regulatory 

mechanisms, SCI argues that FWS should have considered future 

mechanisms under other listing factors. The Court finds that 

plaintiff SCI’s argument is without merit. As other courts have 

found, the ESA does not permit FWS to consider speculative 

future conservation actions when making a listing determination. 

See, e.g., Biodiversity Legal Found. v. Babbitt, 943 F. Supp. 

23, 26 (D.D.C. 1996) (“[T]he Secretary . . . cannot use promises 

of future actions as an excuse for not making a determination 

based on the existing record.”); see also Fund for Animals v. 

Babbitt, 903 F. Supp. 96, 113 (D.D.C. 1996). Moreover, 

established agency policy requires that in making a listing 
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D. The Service Followed Proper Rulemaking Procedures

The Court turns finally to two purported procedural 

deficiencies that have been identified by plaintiffs. First, 

plaintiff State of Alaska claims that FWS failed to satisfy its 

obligation under Section 4(i) of the ESA to provide a “written 

justification” explaining why it issued a final rule that 

conflicts with comments it received from the State. Second, 

plaintiff CF claims that FWS failed to adequately respond to 

specific comments that were raised during the notice-and-comment 

period for the proposed Listing Rule. Each of these procedural 

claims is addressed briefly below.57

1. Plaintiff Alaska’s Claim that the Service

Violated Section 4(i) of the ESA by Failing to 

Provide a Sufficient “Written Justification” in 

Response to Comments 

Under Section 4(i) of the ESA, if FWS receives comments 

from a State (or state agency) disagreeing with all or part of a 

proposed listing, and the agency subsequently issues a final 

 

determination FWS may only consider formalized conservation 

efforts that have been implemented and have been shown to be 

effective. PECE Policy, 68 Fed. Reg. at 15,100. Accordingly, 

the Court finds that FWS was not required to consider 

speculative future efforts to reduce greenhouse gas emissions.

57 The federal defendants have also responded at length to 

what they characterize as a “claim” by plaintiff CBD that the 

polar bear listing rule was improperly influenced by political 

considerations. See Fed. Def. Mot. at 128-32. Plaintiff CBD 

did not in fact raise any such claim. Accordingly, the Court 

will not address the federal defendants’ arguments on this 

issue. 
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rule that conflicts with those comments, it must then provide 

the State with a “written justification” explaining its failure 

to adopt regulations consistent with the agency’s comments. 16 

U.S.C. § 1533(i). The parties agree that on April 9 and October 

22, 2007, the State of Alaska and the Alaska Department of Fish 

and Game submitted comments that disagreed with the proposed 

listing rule for the polar bear and, specifically, with the 

agency’s reliance on population modeling efforts conducted by 

the USGS. See ARL 84248-84274; ARL 124961-125006. The parties 

also agree that on June 17, 2008, after the final Listing Rule 

was issued, FWS sent a lengthy letter to the Governor of Alaska 

with specific responses to the State’s comments pursuant to 16 

U.S.C. § 1533(i). See ARL 11361-11408. Plaintiff State of 

Alaska nonetheless contends that FWS failed to comply with 

Section 4(i) because its responses to five particular comments 

did not adequately “justify” the agency’s actions. Alaska Mot. 

at 7-15. 

The ESA recognizes that states play a crucial role in the 

listing process, and their advice and involvement “must not be 

ignored.” See Alaska Mot. at 6 (citing S. Rep. No. 97-418, at 

12 (1982)). Here, Alaska argues that FWS “effectively ignored”

the State’s concerns, Alaska Mot. at 10, by failing to provide 

an adequate response to the following comments:
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1. Comments on deficiencies in the USGS Carrying 

Capacity Model (Alaska Mot. at 7-10);

2. Comments on deficiencies in the USGS Bayesian 

Network Model (Alaska Mot. at 10-11);

3. Comments on the status of the Southern Beaufort Sea 

polar bear population (Alaska Mot. at 11-13);

4. Comments on the agency’s inappropriate choice of 45 

years as the “foreseeable future” (Alaska Mot. at 

13-14); and

5. Comments on uncertainty in climate change modeling 

(Alaska Mot. at 14-15).58

In support of its position, State of Alaska cites San Luis 

& Delta-Mendota Water Auth. v. Badgley, the only legal precedent 

that deals with a claim under ESA Section 4(i). 136 F. Supp. 2d 

1136 (E.D. Cal. 2000). In that case, regional water authorities 

challenged the listing of a fish species as threatened, and the

NMFS failed to respond to the authorities’ comments with any 

kind of written justification. Id. at 1150-51. The court 

subsequently reversed the NMFS’s listing decision (on other 

grounds, in addition to the 4(i) violation) and remanded to the 

agency. Id. at 1151-52. Alaska contends that this Court should 

do the same. Alaska Mot. at 9-10. 

The federal defendants respond that FWS fully complied with 

Section 4(i) of the ESA when it provided Alaska with its written 

 58 The content of Alaska’s comments is identical to the 

substantive claims raised by the Joint Plaintiffs, which have 

been discussed at length above. The Court therefore will not 

recount the substance of Alaska’s comments and the agency’s 

responses thereto. 
- 112 -

justification on June 17, 2008.59 The federal defendants point 

out that all of Alaska’s comments were addressed, including the 

five at issue here, in the final Listing Rule itself as well as 

in the agency’s response to the State. See Fed. Def. Mot. at 

 59 As a threshold matter, the defendants contend that the 

substance of the agency’s letter is not reviewable, for two 

reasons: (1) the letter of written justification does not 

constitute “final agency action,” as is required for APA review 

(5 U.S.C. § 704); and (2) the agency’s response to comments is 

committed to its discretion by law (5 U.S.C. § 701(a)(2)). Fed. 

Def. Mot. at 122 (citing Bennett v. Spear, 520 U.S. 154, 175 

(1997) (“The APA, by its terms, provides a right to judicial 

review of all ‘final agency action for which there is no other 

adequate remedy in a court,’ and applies universally ‘except to 

the extent that (1) statutes preclude judicial review; or (2) 

agency action is committed to agency discretion by law.”)) 

(internal citations omitted). Alaska responds that, at a 

minimum, the Service’s letter is reviewable as part of a review 

of the final Listing Rule, pursuant to section 704 of the APA. 

Alaska Reply at 9 (citing 5 U.S.C. § 704 (a “procedural . . . 

agency action . . . not directly reviewable is subject to review 

on the review of the final agency action”)). 

Case law provides little guidance on this question. 

Indeed, the only case that addresses a failure to comply with 

ESA Section 4(i) is one where FWS failed to provide any response 

whatsoever, a clear violation of Section 4(i). See San Luis, 

136 F. Supp. 2d at 1151. The Court agrees with Alaska’s 

assessment that the agency’s justification letter is a 

procedural step that becomes reviewable upon review of the final 

agency action (here, the Listing Rule). The ESA mandates that 

the FWS “shall” submit an explanatory written justification to a 

state or state agency if it issues a regulation that conflicts 

with the state’s comments. See Bennett, 520 U.S. at 175 (“[A]ny 

contention that the relevant provision of 16 U.S.C. § 1536(a)(2) 

is discretionary would fly in the face of its text, which uses 

the imperative ‘shall.’”). “It is rudimentary administrative 

law that discretion as to the substance of the ultimate decision 

does not confer discretion to ignore the required procedures of 

decisionmaking.” Id. at 172. The Court is persuaded, however, 

that the standard of review set out in Section 4(i) is not a 

rigorous one. 

 
- 113 -

126. While Alaska may have preferred a different or a more 

detailed explanation, the defendants contend that none is 

required. 

This Court agrees. Section 4(i) requires only that FWS 

provide a “written justification for [the Secretary’s] failure 

to adopt regulations consistent with the [State] agency's 

comments or petition.” 16 U.S.C. § 1533(i). FWS did so here. 

There is no dispute that FWS responded in writing to two sets of 

comments from the State of Alaska. Moreover, FWS specifically 

addressed each of the issues identified by Alaska, both in its 

response letter and in the response to comments that appears in 

the Listing Rule itself. See, e.g., ARL 11394-95 (carrying 

capacity model);60 ARL 11405-08 (Bayesian Network model); ARL 

11389, 11399-404 (Southern Beaufort Sea population); ARL 11365-

66, 11382-84 (“foreseeable future”); ARL 11363-70, 11395-98 

(scientific uncertainty and climate change modeling). Indeed, 

Alaska’s own pleadings make clear that FWS did at least attempt

to respond to each of the State’s concerns. Having carefully 

 60 The Court was unable to locate many of the specific 

concerns that Alaska purports to have raised in its comments 

with regard to the carrying capacity model. The Court therefore 

notes that FWS was not obligated to respond to arguments that 

were not, in fact, raised. See Vt. Yankee Nuclear Power Corp. 

v. Natural Res. Def. Council, 435 U.S. 519, 553-54 (1978) 

(agency proceedings “should not be a game or forum to engage in 

unjustified obstructionism by making cryptic and obscure 

references to matters,” and then seeking to invalidate agency 

action on grounds that the agency failed to consider the 

matters). 
- 114 -

reviewed the parties’ arguments, the State’s comments, and the 

agency’s responses, the Court is satisfied that FWS did not 

ignore any of Alaska’s concerns. Accordingly, the Court 

concludes that FWS fulfilled its duty to respond to Alaska’s 

comments under ESA Section 4(i). 

2. Plaintiff CF’s Claim that FWS Failed to Respond 

to Significant Comments

In its supplemental motion for summary judgment, plaintiff 

CF contends that FWS also failed to respond to certain 

“significant” comments which “if true, would require a change in 

the proposed rule.” See CF Mot. at 20 (citing Am. Mining Cong. 

v. EPA, 907 F.2d 1179, 1188 (D.C. Cir. 1990)).61 Plaintiff CF 

 61 CF identifies nine concerns which it purports to have 

raised in comments on the proposed rule and which, it claims, 

were never addressed. Specifically, CF highlights:

1. The agency’s failure to consider the role of sun 

spot cycles as a primary climate factor;

2. The agency’s failure to consider literature on the 

dynamics of solar irradiation;

3. The agency’s failure to explain why it relied so 

heavily on a declining trend among the Western 

Hudson Bay polar bear population when that trend is 

offset by gains in polar bear numbers in other 

populations;

4. The agency’s failure to objectively review data;

5. The agency’s failure to specify the degree and 

nature of impacts to polar bears from receding sea 

ice;

6. The agency’s failure to explain how a decline in the 

Western Hudson Bay polar bear population is 

attributable to global warming;

7. The agency’s failure to address why the polar bear 

survived two historical warming periods;
- 115 -

did not, however, pursue this claim in its reply brief. 

Accordingly, because plaintiff CF appears to have abandoned this 

procedural claim, the Court will not consider it further. See 

Bd. of Regents of the Univ. of Wash. v. EPA, 86 F.3d 1214, 1222 

(D.C. Cir. 1996) (declining to rule on a claim that “petitioners 

appear to have dropped”).62 

IV. CONCLUSION

For the foregoing reasons, plaintiffs’ motions for summary 

judgment are hereby DENIED, the federal defendants’ cross-motion 

for summary judgment is hereby GRANTED and the defendantintervenors’ cross-motions for summary judgment are hereby 

GRANTED. An appropriate Order accompanies this Memorandum 

Opinion. 

 

8. The agency’s failure to explain projected declines 

in the Southern Beaufort Sea polar bear population 

when reports indicate “no correlation between 

demographic changes and ice melt” in that region; 

and

9. The agency’s failure to consider that warming will 

actually improve polar bear habitat in the 

northernmost Arctic region. 

See CF Mot. at 20-22. 

62 Even if this claim were not abandoned, for the reasons set 

out in the federal defendants’ response brief and on the basis 

of the administrative record the Court is persuaded that FWS 

adequately addressed plaintiff CF’s comments, to the extent any 

response was required. See Fed. Def. Mot. at 133-37. 
- 116 -

SO ORDERED. 

Signed: Emmet G. Sullivan

United States District Judge

June 30, 2011