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DEFS.’ MOTION IN LIMINE 

CONCERNING UNDISPUTED FACTS

JEFFREY H. WOOD

Acting Assistant Attorney General

Environment & Natural Resources Division

U.S. Department of Justice

LISA LYNNE RUSSELL, Chief

GUILLERMO A. MONTERO, Assistant Chief

SEAN C. DUFFY (NY Bar No. 4103131)

MARISSA PIROPATO (MA Bar No. 651630)

CLARE BORONOW (admitted to MD bar)

FRANK J. SINGER (CA Bar No. 227459)

ERIKA NORMAN (CA Bar No. 268425)

Trial Attorneys

Natural Resources Section

601 D Street NW

Washington, DC 20004

(202) 305-0445 (Duffy)

sean.c.duffy@usdoj.gov

Attorneys for Defendants

UNITED STATES DISTRICT COURT

DISTRICT OF OREGON

KELSEY CASCADIA ROSE JULIANA,

et al.,

Plaintiffs,

v.

The United States of America, et al.,

Defendants.

Case No.: 6:15-cv-01517-TC

DEFENDANTS’ MOTION IN LIMINE

TO EXCLUDE CERTAIN TESTIMONY 

OF SIX EXPERTS AND

MEMORANDUM OF POINTS AND 

AUTHORITIES IN SUPPORT 

THEREOF

Case 6:15-cv-01517-AA Document 371 Filed 10/15/18 Page 1 of 6
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DEFS.’ MOTION IN LIMINE 

CONCERNING UNDISPUTED FACTS

DEFENDANTS’ MOTION IN LIMINE TO EXCLUDE 

CERTAIN TESTIMONY OF SIX EXPERTS

Plaintiffs have estimated that the trial set to commence on October 29 could take up to 

eight weeks, a figure which no doubt reflects Plaintiffs’ intent to consume numerous days 

presenting expert testimony on issues not in dispute in this case – in particular, the effects of 

greenhouse gas (GHG) emissions and climate change. The parties explored these details in 

excruciating detail in the lengthy complaint and answer filed in this case. Further exploration at 

trial would be unhelpful to the Court as trier of fact and an inefficient use of judicial and party 

resources. These concerns may be avoided under either Rule 403 or Rule 702(a) of the Federal 

Rules of Evidence, either of which authorizes the Court to exclude such evidence at trial. 

Defendants seek exclusion of this evidence because it pertains to contentions that are 

admitted and thus not in dispute. The Court should exclude the evidence because it cannot be 

expected to “help the trier of fact to understand the evidence or to determine a fact in issue,” Fed. 

R. Evid. 702(a) (emphasis added), and because the probative value of such evidence is 

“substantially outweighed by a danger of . . . undue delay, wasting time, or needlessly presenting

cumulative evidence.” Fed. R. Evid. 403. Accordingly, Defendants respectfully request an order 

excluding such testimony from trial, as more fully described below.

MEMORANDUM OF LAW

I. LEGAL STANDARD

Rule 702 of the Federal Rules of Evidence sets forth the standard for admissibility of 

expert opinion testimony. It provides that a witness who is qualified by “knowledge, skill, 

experience, training, or education” may testify in the form of an opinion if, among other things, 

“the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to 

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DEFS.’ MOTION IN LIMINE 

CONCERNING UNDISPUTED FACTS

understand the evidence or to determine a fact in issue.” Fed. R. Evid. 702. The trial court acts 

as the “gatekeeper” in admitting or excluding proposed expert testimony. In this role, the Court 

is charged with

assuring that expert testimony “rests on a reliable foundation and is relevant to the 

task at hand.” The gatekeeper role “entails a preliminary assessment of whether the 

reasoning or methodology underlying the testimony is . . . valid and of whether 

that reasoning or methodology properly can be applied to the facts in issue.”

United States v. Hermanek, 289 F.3d 1076, 1093 (9th Cir. 2002) (citation omitted) (quoting 

Daubert v. Merrell Dow Pharms., Inc., 509 U.S. 579, 592–93 (1993)). In addition, under Rule 

403, the Court may exclude evidence “if its probative value is substantially outweighed by a 

danger of . . . undue delay, wasting time, or needlessly presenting cumulative evidence.” Fed. R. 

Evid. 403.

II. ARGUMENT

The amended complaint in this case, ECF No. 7, consists of ninety-five pages and a host 

of allegations, set forth in more than 300 numbered paragraphs. Defendants assessed these 

allegations and responded in a seventy-page answer. Their responses include numerous 

admissions, many of which demonstrate that the parties, for purposes of this litigation, do not 

dispute a great number of the effects of GHG emissions and climate change. See, e.g., Fed. 

Defs.’ Answer to First Am. Compl. ¶¶ 202-255, ECF No. 98 (admissions concerning climate 

change science and projected impacts). The resolution of complex questions of climate science 

at trial is not necessary to dispose of the claims in this lawsuit, nor would opining on such 

matters be appropriate in this forum where, for purposes of this litigation, the government’s 

answer does not dispute those matters. 

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DEFS.’ MOTION IN LIMINE 

CONCERNING UNDISPUTED FACTS

Nonetheless, it appears Plaintiffs intend to present lengthy testimony on fact, opinion and 

law from six witnesses, specifically, Dr. James E. Hansen, Ph.D., Dr. Ove Hoegh-Guldberg, 

Ph.D., Dr. Eric Rignot Ph.D., Dr. Steven W. Running, Ph.D., Dr. Kevin E. Trenberth, Sc.D., and 

Dr. Harold R. Wanless. Defendants base this expectation on the nearly 200 pages of fact

testimony, opinion testimony, maps and other graphics, and legal conclusions contained in the 

expert reports of these six witnesses. All six witnesses discuss in considerable detail the causes 

of climate change and its effects on earth’s natural and biological systems. All six note that 

combustion of fossil fuels produces carbon dioxide (CO2) and other GHGs, which cause global 

warming. All six discuss the effects of global warming, variously including polar ice melt, 

earlier annual snow melt, reduced snow pack, sea-level rise, sea temperature increases, threats to 

coastal cities, adverse impacts to coral reefs and the life forms they support, more powerful 

storms and hurricanes, wildfires, drought, floods, and a variety of other impacts. The answer 

acknowledges all of these effects for purpose of this litigation.

The trial judge has discretion to determine whether expert testimony is admitted, see 

United States v. Rincon, 28 F.3d 921, 925 (9th Cir. 1994), and “may exclude testimony even if it 

satisfies the test set forth in” Daubert, 509 U.S. at 592–93. United States v. Strode, No. 99-

30074, 2000 WL 890740, at *2 (9th Cir. 2000). Further, “even if otherwise admissible under 

Rule 702, expert testimony ‘may be excluded if its probative value is substantially outweighed 

. . . by considerations of undue delay, waste of time, or needless presentation of cumulative 

evidence.’” Perfect 10, Inc. v. Giganews, Inc., No. CV 11-07098-AB (SHX), 2014 WL 

10894452, at *3 (C.D. Cal. Oct. 31, 2014) (quoting Fed. R. Evid. 403).

The Court should exercise its discretion here by excluding any testimony reflected in the 

six reports that is cumulative or that relates to matters not in dispute. As to the former, Rule 403 

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DEFS.’ MOTION IN LIMINE 

CONCERNING UNDISPUTED FACTS

permits the Court to exclude needlessly cumulative testimony that has little incremental value. 

United States v. Miguel, 87 Fed.Appx. 67, 68-69 (9th Cir. 2004). “Cumulative evidence 

replicates other admitted evidence.” United States v. Ives, 609 F.2d 930, 933 (9th Cir. 1979). A 

witness’s testimony may be needlessly cumulative if a party presents evidence bearing on the 

same point through other witnesses. Rogers v. Raymark Indus., Inc., 922 F.2d 1426, 1430 (9th 

Cir. 1991) (affirming district court’s decision to exclude witness testimony that had little 

probative value and was cumulative). As to the latter, courts have also excluded evidence 

relating to matters not in dispute. See Thames v. Miller, No. CV04-00644 DAE/LEK, 2007 WL 

1303014, at *3 (D. Haw. May 2, 2007), aff’d, 334 F. App’x 136 (9th Cir. 2009) (granting 

defendant’s motion in limine to preclude plaintiff from producing any testimony or evidence 

pertaining to a property that was not in dispute); see also Diviero v. Uniroyal Goodrich Tire Co., 

114 F.3d 851, 853 (9th Cir. 1997) (affirming district court decision to exclude evidence that 

would not assist the trier of fact); ” Little Oil Co., Inc. v. Atlantic Richfield Co., 852 F.2d 441, 

446 (9th Cir. 1988) (noting that to be admissible, the trier of fact must “receive ‘appreciable 

help’”) (citations omitted). Here, the presentation of expert testimony at trial concerning the 

effects of GHG emissions and climate change cannot be expected to help the trier of fact to 

understand the evidence or determine a fact in issue. 

In light of Defendants’ admissions, numerous assertions by Plaintiffs concerning effects 

of GHG emissions and climate change are not in dispute for purposes of this litigation. 

Testimony concerning these matters will not help the Court determine any facts in issue and 

would needlessly expend the Court’s and the parties’ resources, while defeating the goal of 

judicial economy. For that reason, Plaintiffs’ proposed expert testimony on those issues is not 

necessary to help this Court “understand the evidence or to determine a fact in issue,” Fed. R. 

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DEFS.’ MOTION IN LIMINE 

CONCERNING UNDISPUTED FACTS

Evid. 702, and its probative value “is substantially outweighed by a danger of . . . undue delay, 

wasting time, or needlessly presenting cumulative evidence.” Fed. R. Evid. 403. The testimony 

should be precluded. 

III. CONCLUSION

The interests of justice and judicial economy will be served by avoiding the wasteful, 

time-consuming presentation of cumulative evidence concerning facts not in issue. Accordingly, 

this Court should enter an order in limine excluding at trial any testimony concerning the facts 

that Defendants have admitted in their Answer for purposes of this litigation.

Dated: October 15, 2018 Respectfully submitted,

JEFFREY H. WOOD

Acting Assistant Attorney General

Environment and Natural Resources Division

U.S. Department of Justice

/s/ Erika Norman

LISA LYNNE RUSSELL

GUILLERMO A. MONTERO

SEAN C. DUFFY (NY Bar No. 4103131)

MARISSA PIROPATO (MA Bar No. 651630)

CLARE BORONOW (admitted to MD bar)

FRANK J. SINGER (CA Bar No. 227459)

ERIKA NORMAN (CA Bar No. 268425)

601 D Street NW

Washington, DC 20004

Telephone: (202) 305-0475

Facsimile: (202) 305-0506

Erika.Norman@usdoj.gov

Attorneys for Defendants

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