NREL is a national laboratory of the U.S. Department of Energy

Office of Energy Efficiency & Renewable Energy

Operated by the Alliance for Sustainable Energy, LLC

This report is available at no cost from the National Renewable Energy

Laboratory (NREL) at www.nrel.gov/publications.

Contract No. DE-AC36-08GO28308

A Climate Change 

Vulnerability Assessment 

Report for the National 

Renewable Energy Laboratory 

May 23, 2014—June 5, 2015 

J. Vogel, M. O’Grady, and S. Renfrow

Abt Environmental Research 

Boulder, Colorado 

NREL Technical Monitor: Lissa Myers

Subcontract Report 

NREL/SR-3500-64174 

September 2015 
NREL is a national laboratory of the U.S. Department of Energy

Office of Energy Efficiency & Renewable Energy

Operated by the Alliance for Sustainable Energy, LLC 

This report is available at no cost from the National Renewable Energy

Laboratory (NREL) at www.nrel.gov/publications.

Contract No. DE-AC36-08GO28308

National Renewable Energy Laboratory

15013 Denver West Parkway

Golden, CO 80401

303-275-3000 • www.nrel.gov

A Climate Change 

Vulnerability Assessment 

Report for the National 

Renewable Energy Laboratory 

May 23, 2014—June 5, 2015 

J. Vogel, M. O’Grady, and S. Renfrow

Abt Environmental Research 

Boulder, Colorado 

NREL Technical Monitor: Lissa Myers

Prepared under Subcontract No. AFG-4-42413-01

Subcontract Report 

NREL/SR-3500-64174 

September 2015
NOTICE

This report was prepared as an account of work sponsored by an agency of the United States government. 

Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, 

express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of 

any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately 

owned rights. Reference herein to any specific commercial product, process, or service by trade name, 

trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, 

or favoring by the United States government or any agency thereof. The views and opinions of authors expressed 

herein do not necessarily state or reflect those of the United States government or any agency thereof.

This report is available at no cost from the National Renewable Energy

Laboratory (NREL) at www.nrel.gov/publications. 

Available electronically at SciTech Connect http:/www.osti.gov/scitech

Available for a processing fee to U.S. Department of Energy

and its contractors, in paper, from:

U.S. Department of Energy

Office of Scientific and Technical Information

P.O. Box 62

Oak Ridge, TN 37831-0062

OSTI http://www.osti.gov

Phone: 865.576.8401

Fax: 865.576.5728

Email: reports@osti.gov

Available for sale to the public, in paper, from:

U.S. Department of Commerce

National Technical Information Service

5301 Shawnee Road

Alexandria, VA 22312

NTIS http://www.ntis.gov

Phone: 800.553.6847 or 703.605.6000

Fax: 703.605.6900

Email: orders@ntis.gov

Cover Photos by Dennis Schroeder: (left to right) NREL 26173, NREL 18302, NREL 19758, NREL 29642, NREL 19795.

NREL prints on paper that contains recycled content.
iii

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Acknowledgments

The authors thank project team members, including Morgan Lommele of PACE Consulting, Eric 

Gordon and Imtiaz Rangwala of the Western Water Assessment, and Joel Smith of Abt 

Environmental Research. The authors would also like to thank the National Renewable Energy 

Laboratory (NREL) project team of Frank Rukavina, Lissa Myers, Jennifer Daw, and Suzanne 

Belmont for their careful attention to project details and their reviews of this report. A special 

thank you goes to NREL’s Eliza Hotchkiss for her extensive review of the report. Finally, thanks 

to the many NREL staff who supported this project, either as steering committee members or as 

participants in focus group discussions. 
iv

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

List of Acronyms

BAE building area engineer 

CCRP Climate Change Resiliency and Preparedness

DOE U.S. Department of Energy 

ESIF Energy Systems Integration Facility 

GCM general circulation model 

GHG greenhouse gas

HVAC heating, ventilating, and air conditioning

IT information technology 

NREL National Renewable Energy Laboratory 

NWTC National Wind Technology Center 

PEMP Performance Evaluation and Measurement Plan

PV photovoltaic 

RCP Representative Concentration Pathway

RSF Research Support Facility

SITE Ops Sustainability, Infrastructure Transformation, and Engineering Operations

STM South Table Mountain campus
v 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Executive Summary

Introduction

Observations and projections indicate that the Front Range of Colorado, including the cities of 

Golden and Louisville, are experiencing a change in climate. In winter 2014, the National 

Renewable Energy Laboratory (NREL), which has one site in Golden and one near Louisville, 

worked with Abt Environmental Research1

 to develop a vulnerability assessment and a resiliency 

action plan. These efforts, which were part of NREL’s Climate Change Resiliency and 

Preparedness project, were funded by the U.S. Department of Energy’s Sustainability 

Performance Office; lessons learned from this pilot project may inform resiliency planning at 

other U.S. Department of Energy sites. 

This Executive Summary presents a combined overview of the two stages of the project, which 

culminated in this report and A Resiliency Action Plan for the National Renewable Energy 

Laboratory (Vogel et al. 2015). This report covers the vulnerability assessment, but this 

Executive Summary covers both the vulnerability assessment and the resiliency action plan. The 

subsequent resiliency action plan report takes the results of this vulnerability assessment and 

develops and evaluates actions for NREL to consider for reducing those vulnerabilities. 

NREL’s Vulnerabilities

To begin identifying vulnerabilities that are specific to NREL, the project team first developed a 

framework to explore NREL’s unique circumstances. This framework combines three key 

organizational objectives, based on NREL’s 2014 Annual Plan and Performance Evaluation and 

Measurement Plan (NREL 2014) goals and six key resources that are deemed essential to the 

continued operation of NREL’s facilities and research (Table ES-1). 

Table ES-1. Impacts Framework

Key Objectives

Key Resources2

Water Energy Physical 

Space

Site 

Access Workforce

Research 

and

Mission

1.Execute research, analysis, 

and deployment

2.Deliver facility stewardship

3.Sustain laboratory 

operations

The framework was used to conduct five in-person work group interviews with small groups of 

NREL staff members to brainstorm a comprehensive list of NREL’s vulnerabilities from climate 

change. The U.S. Environmental Protection Agency’s Climate Ready Estuaries Program (EPA 

2013) method was used as a guide to perform a risk analysis to discern NREL’s highest risk 

climate change vulnerabilities. 

 

1

NREL originally contracted with Stratus Consulting Inc., which later became part of Abt Environmental Research, 

a wholly owned subsidiary of Abt Associates. 2

For the Impacts Framework NREL defined key resource as a system, program, material, component, or other 

resource needed to achieve the key objectives. 
vi 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

The risk analysis considered the magnitude of the consequences of vulnerabilities on NREL’s 

key resources, should the potential vulnerability occur. Climate change experts assessed and 

scored the likelihood that climate variables associated with each vulnerability will change. The 

magnitude of consequence score was then combined with the likelihood score to determine an 

overall risk score for the vulnerability; this score was used to determine which vulnerabilities the 

resiliency action plan would address. 

Table ES-2 presents an example of how the consequence and likelihood scores were combined to 

determine an overall risk score. Red indicates high risk and dark orange indicates medium-tohigh risk. 

Table ES-2. Example Vulnerability to Workforce and Its Scoring

Vulnerability Consequence Climate Variable Likelihood Risk 

Score

Overall 

Risk Score

Staff may not be able 

to conduct outdoor 

research and other 

outdoor activities

Medium

Increased lightning 

patterns and longer 

lightning season

Medium-tohighMediumto-high Medium-tohigh Increased extreme 

heat events High Mediumto-high

Only the vulnerabilities with high and medium-to-high overall risk scores were selected for 

inclusion in the resiliency action plan (see Vogel et al. 2015). Table ES-3 lists the vulnerabilities 

that received the highest overall risk scores.

Table ES-3. Vulnerabilities with High and Medium-to-High Overall Risk Score

Key 

Resource Vulnerability

Associated Climate 

Variables Likely To 

Change

Overall Risk 

Score*

Water

Each campus has only one water supplier and no 

backup options

Stream flows, 

precipitation, drought, 

evapotranspiration

High

NREL may not be able to continue to rely on

evaporative cooling and chillers Temperature Medium-to-high

Energy

NREL has only one electricity supplier and depends 

on electricity to support mission-critical activities, 

including information technology connectivity

Temperature, 

precipitation, lightning, 

fire 

High

Physical 

space 

Landslides may occur because the South Table 

Mountain campus buildings are close to the mesa 

slope

Precipitation and fire High

Site flooding may occur because the South Table 

Mountain campus has poor drainage Precipitation Medium-to-high 

Damage to climate-sensitive equipment may disrupt 

research

Temperature, 

precipitation, lightning, 

fire 

Medium-to-high 

Site 

access 

Key staff may not be able to access NREL’s sites to 

respond to emergencies and to conduct research; 

some situations may require staff redundancy

Temperature, 

precipitation, fire, 

lightning

Medium-to-high 
vii 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Key 

Resource Vulnerability

Associated Climate 

Variables Likely To 

Change

Overall Risk 

Score*

Workforce Staff may not be able to conduct outdoor research 

and other outdoor activities

Temperature and 

lightning Medium-to-high 

Research/

mission

NREL’s reputation as a sustainable campus may be 

damaged if it moves to traditional air conditioners for 

space cooling

Temperature Medium-to-high 

* Red indicates high risk and dark orange indicates medium-to-high risk. 

Resiliency Actions

During the resiliency action plan stage of the project, the team categorized each high-risk and 

medium-to-high-risk vulnerability as one to be mitigated, transferred, accepted, or 

avoided.3 Eight of the nine vulnerabilities fell in the category of mitigate; only one, “NREL’s 

reputation as a sustainable campus may be damaged,” fell in the accept category with no action 

needed. 

Six in-person4 work group interviews were conducted with small groups of NREL staff members 

to identify a comprehensive list of potential resiliency actions that could address each of the 

eight vulnerabilities identified for mitigation (see Table ES-3). Each resiliency action was scored 

based on three evaluation criteria: effectiveness, feasibility, and cost. These score assignments 

were based on the preliminary discussions of the work groups and on the team members’ 

professional judgment; work group participants then refined and validated these preliminary 

scores. One of three recommended approaches was assigned to each action:

• Do now (green) was reserved for resiliency actions that were no- or low-regrets actions 

that NREL should reasonably pursue, even if climate change is not considered. 

• Continue evaluating (orange) was reserved for resiliency actions that needed further 

exploration before they could be either endorsed as do now actions or completely set 

aside.

• Remove from consideration (red) was reserved for resiliency actions that were untenable 

for one or more reasons and that should be set aside (see Vogel et al. 2015). 

Summary of Findings

Table ES-4 summarizes the resiliency actions, categorized by key resource and vulnerability, 

which NREL may wish to pursue in the next stage of the project. The table also includes the 

overall risk score and the project team’s recommended approach. These recommendations are 

preliminary; additional analysis may be necessary to ensure that any selected actions best reflect 

NREL’s capabilities and priorities. For a full discussion of next steps, including best practices in 

the field of resiliency planning based on the experiences of other organizations, refer to Vogel et 

al. (2015) Section 4. 

 

3

Categories were based on those in Climate Ready Estuaries (EPA 2013). 4

One telephone interview was conducted because of logistical constraints.
viii

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Table ES-4. Vulnerabilities, Resiliency Actions, and High-Level Scoresa

Key 

Resource Vulnerability Overall Risk Score Resiliency Actions Recommended Approach

Multiple

Cross-cutting solutions identified to 

mitigate across multiple 

vulnerabilitiesb

Not applicable

Integrate climate considerations 

into existing operations and 

practices

Do now

Create and implement a climate 

monitoring and communication 

system

Do now

Water

Each campus has only one water 

supplier and no backup options High

Develop a water-shortage 

contingency plan Do now

Connect the National Wind 

Technology Center to a public 

water system

Continue 

evaluating

NREL may not be able to continue to 

rely on evaporative cooling and 

chiller

Medium-to-high

Create and implement a climate 

monitoring and communication 

system

Do now

Add conventional backup air 

conditioning

Continue 

evaluating

Energy

NREL has only one electricity 

supplier and depends on electricity 

to support mission-critical activities, 

including information technology 

connectivity

High

Improve demand management Do now

Install a battery supply Do now

Establish a microgrid Continue 

evaluating

Physical 

space

Site flooding and landslides may 

occur at the South Table Mountain 

campusc

High/medium-to-highc

Evaluate and redesign the site to 

improve drainage and slope 

stability

Do now

Damage to climate-sensitive 

equipment may disrupt research Medium-to-high

Integrate climate considerations 

into existing operations and 

practices

Do now

Retrofit climate-sensitive 

equipment

Continue 

evaluating
ix

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Key 

Resource Vulnerability Overall Risk Score Resiliency Actions Recommended Approach

Site access

Key staff may not be able to access 

NREL’s sites to respond to 

emergencies and to conduct 

research; some situations may 

require staff redundancyd

Medium-to-high

No resiliency action proposed 

because NREL is already 

addressing this issued

No recommended 

approach beyond 

current NREL 

effortsd

Workforce

Staff may not be able to conduct 

outdoor research and other outdoor 

activities

Medium-to-high

Integrate climate considerations 

into existing operations and 

practices

Do now

Create and implement a climate 

monitoring and communication 

system

Do now

Install outdoor structures for 

protection from hazardous weather 

events

Continue 

evaluating

a Table ES-4 presents only the vulnerabilities that received a medium-to-high or high overall risk score, fell in the mitigate category and received a do 

now or continue evaluating recommendation (see Executive Summary Section NREL’s Vulnerabilities).

b During the resiliency action plan work group discussions, various cross-cutting resiliency actions came to light; these actions apply to several 

vulnerabilities.

c In the vulnerability assessment stage of the project, landslides and flooding were separate vulnerabilities; their resiliency actions would be similar so 

they were later combined.

d A resiliency action plan work group was not convened to discuss the inability of key staff to access NREL’s sites because NREL is already addressing 

this vulnerability—which is a concern even without considering climate change—through its Continuity of Operations Plan.
x 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Table of Contents

1 Introduction........................................................................................................................................... 1

1.1 Climate Change along Colorado’s Front Range............................................................................ 1

1.1.1 Observations..................................................................................................................... 2

1.1.2 Climate Projections.......................................................................................................... 2

1.1.3 Extreme Event Projections............................................................................................... 2

1.1.4 A Note about Climate Variability .................................................................................... 3

1.2 NREL’s Climate Change Resiliency and Preparedness Project.................................................... 4

2 Vulnerability Assessment.................................................................................................................... 5

2.1 Creating an Impacts Framework ................................................................................................... 5

2.1.1 Identify Key Resources and Objectives ........................................................................... 5

2.1.2 Develop Questions To Uncover Potential Vulnerabilities ............................................... 6

2.2 Identifying NREL’s Potential Vulnerabilities............................................................................... 6

2.2.1 Water.............................................................................................................................. 10

2.2.2 Energy ............................................................................................................................ 13

2.2.3 Physical Space................................................................................................................ 15

2.2.4 Site Access..................................................................................................................... 18

2.2.5 Workforce ...................................................................................................................... 20

2.2.6 Research and Mission..................................................................................................... 20

2.3 Identifying NREL’s Highest Risk Vulnerabilities ...................................................................... 21

3 Next Stage: The Resiliency Action Plan........................................................................................... 22

Glossary..................................................................................................................................................... 24

References................................................................................................................................................. 26

Appendix A. Climate Change along the Front Range ........................................................................... 28

Appendix B. High-Level Overview of Projected Climate Changes for the Front Range.................... 34

Appendix C. Notable Destructive Weather Events Since 1985 ............................................................ 35

Appendix D. Vulnerability Work Group Guiding Questions ................................................................. 38
xi 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

List of Figures

Figure 1. Risk score matrix......................................................................................................................... 10

Figure A-1. Trends in the upper ocean heat content................................................................................... 29

Figure A-2. Annual temperature departures for the 1913–2012 time period relative to 1971–2000 average 

in Colorado’s northern Front Range ...................................................................................... 30

Figure A-3. One rendition of our current understanding and detection of changes in different climate and 

weather extremes because of climate change......................................................................... 32

List of Tables

Table 1. Impacts Framework ........................................................................................................................ 6

Table 2. Climate Variables of Concern and Associated Likelihood of Changing ........................................ 9

Table 3. Water: Consequence, Likelihood, Risk, and Overall Risk Scores................................................ 12

Table 4. Energy: Consequence, Likelihood, Risk, and Overall Risk Scores.............................................. 14

Table 5. Physical Space: Consequence, Likelihood, Risk, and Overall Risk Scores.................................. 17

Table 6. Site Access: Consequence, Likelihood, Risk, and Overall Risk Scores....................................... 19

Table 7. Workforce: Consequence, Likelihood, Risk, and Overall Risk Scores ........................................ 20

Table 8. Research and Mission: Consequence, Likelihood, Risk, and Overall Risk Scores ...................... 21

Table 9. Vulnerabilities with the Highest Overall Risk Score .................................................................... 22

Table A-1. Destructive Weather Events in Colorado Since 1985............................................................... 35

List of Boxes

Box 1. Scoring Vulnerabilities by Their Magnitude of Consequence ................................................. 8 

Box 2. Scoring Climate Variables by the Likelihood of Change ........................................................ 8 

Box 3. Scoring Each Vulnerability for Risk and Overall Risk.......................................................... 10
1 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

1 Introduction

The U.S. Department of Energy’s (DOE’s) National Renewable Energy Laboratory (NREL), in 

Golden, Colorado, focuses on renewable energy and energy efficiency research. Its portfolio 

includes advancing renewable energy technologies that can help meet the nation’s energy and 

environmental goals. NREL seeks to better understand the potential effects of climate change on 

the laboratory—and therefore on its mission—to ensure its ongoing success. Planning today for a 

changing climate can reduce NREL’s risks and improve its resiliency to climate-related 

vulnerabilities.

This report presents a vulnerability assessment for NREL. The assessment was conducted in fall 

2014 to identify NREL’s climate change vulnerabilities and the aspects of NREL’s mission or 

operations that may be affected by a changing climate. 

The report begins with a background on the impetus for the assessment, continues with the 

assessment, and concludes with information about the next steps in the adaptation process. 

Appendices A, B, and C include an overview of the region’s latest climate science and recent 

extreme events, and Appendix D is a document that the project team created to support the 

vulnerability assessment process.

NREL selected a risk management method established by the U.S. Environmental Protection 

Agency’s Climate Ready Estuaries Program (EPA 2013) as a guide for the analysis. The risk 

management process presents a systematic way to look at potential climate-related risks and the 

potential impact of those risks if they were to happen on achieving organizational goals. 

The vulnerability assessment is the first part of a two phase project collectively called NREL’s

Climate Change Resiliency and Preparedness Project (CCRP). NREL hired adaptation experts 

from Stratus Consulting Inc. (now known as Abt Environmental Research (Abt)), an 

environmental consulting firm with demonstrated local adaptation planning experience and 

established relationships with climate science experts from Western Water Assessment (WWA)

to lead the project. WWA a consortium of climate scientists from the University of Colorado at 

Boulder and the National Atmospheric and Oceanic Administration Regional Integrated Sciences

and Assessments program and other regional partners provided specific climate science analysis 

that supported the project. Abt and WWA in partnership with a core group of NREL project staff 

(together referred to as “the project team”) executed the CCRP project.

1.1 Climate Change along Colorado’s Front Range

The major motivation for NREL’s vulnerability assessment was climate change. Climate science 

indicates that climate is already changing and will continue to change (Stocker et al. 2013). The 

Front Range of Colorado, including NREL’s sites in Golden and near Louisville, is likely to 

experience rising temperatures, changes in precipitation, and increasingly severe weather events. 

Section 1.1.1 through Section 1.1.4 summarize the current state of knowledge about the observed 

and projected effects of climate change on Colorado.5 For more details, see Appendix A. 

 

5

This summary and Appendices A, B, and C were developed based on the expertise of climate experts at the 

Western Water Assessment, a National Oceanic and Atmospheric Administration Regional Integrated Sciences and 

Assessments program associated with the University of Colorado. 
2 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

1.1.1 Observations 

Ongoing climate observations show some changes in Colorado and along the Front Range and 

indicate:

• A warming trend, particularly since the mid-1990s 

• No long-term discernable trend in annual precipitation amounts, April 1 snowpack, heavy 

precipitation, or flooding events 

• A 1- to 4-week shift earlier in the timing of snowmelt and peak spring runoff that is likely 

due to a combination of higher spring temperatures and enhanced solar radiation 

absorption from deposits of dust on snow (Lukas et al. 2014) 

• An increase in drought conditions in the last 30 years that reflects the combined effects of 

below-average precipitation and higher temperatures since 2000. 

1.1.2 Climate Projections 

Projections of climate in Colorado and along the Front Range rely on climate models.6 These 

projections vary in severity depending on the atmospheric greenhouse gas (GHG) concentration 

trajectory and emissions scenarios used. In summary, projections show: 

• Increases in statewide temperatures by 2050 of +2.5°F to +5°F, relative to the 1971–2000 

period under a moderate-emissions scenario (RCP 4.57); and of +3.5°F to +6.5°F under a 

high-emissions scenario (RCP 8.5) (Lukas et al. 2014) 

• Disagreement about average annual precipitation changes, with a –5% to +6% change by 

2050 under a moderate-emissions scenario (RCP 4.5); and a –3% to +8% change under a 

high-emissions scenario (RCP 8.5)

• Increases in winter precipitation

• An even chance of increases or decreases in annual stream flow along the Front Range 

• A 1- to 3-week shift earlier in the timing of spring runoff by 2050 that will cause late 

summer and early autumn runoff to decrease (Lukas et al. 2014) 

• Decreases in relative humidity along the Front Range, with the greatest decreases in 

spring and summer (Wright et al. 2010; Pierce et al. 2013).8

1.1.3 Extreme Event Projections

Extreme events (heat waves, severe drought, heavy precipitation, and winter storms) generally 

have a much greater effect on socioeconomic and ecosystem structures and functionality than do 

changes in climate averages. Their sudden or single-event nature makes extreme events harder to 

 

6

Climate models, or general circulation models (GCMs), are numerical models that simulate the physical processes 

in the atmosphere, ocean, cryosphere, and land surface. They are the most sophisticated tools available for 

simulating the response of the global climate system to increasing GHG concentrations. (See Appendix A.) 

7 The Representative Concentration Pathways (RCPs) provide various projections of GHG concentrations to be used 

in climate change analysis and predictions. The four pathways: RCP8.5, RCP6, RCP4.5, and RCP2.6 come from the 

Intergovernmental Panel on Climate Change Fifth Assessment Report.

8

This climate variable features no vulnerabilities, because only an increase in relative humidity would pose a 

problem for NREL. 
3 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

prepare for and adjust to than incremental changes over longer periods. In summary, the model 

projections of extremes in Colorado and along the Front Range show, with varying levels of 

confidence: 

• Increases in the frequency of intense heat waves (Lukas et al. 2014). 

• A sharp increase in the ratio of new record-high temperatures to record-low temperatures 

during the 21st century (Meehl et al. 2009). Observations already indicate that the 

frequency of new record-high temperatures has doubled in relation to new record-low 

temperatures in the United States; in the absence of climate change, the ratio should be 

one-to-one.

• A greater proportion of precipitation will be received from the heaviest precipitation 

events because of climate change (Wuebbles et al. 2014); this is partly related to the 

increases in moisture and energy that are associated with individual storm systems. The 

available observations in Colorado do not yet provide discernable evidence of this trend; 

however, other parts of the United States and the world have experienced increases in the 

frequency of heavy precipitation events (Melillo et al. 2014). 

• Transition from hail to rain along the Front Range as temperatures warm; this results in 

higher flash-flood risks (Garfin et al. 2013). 

• Intensified drought caused by future warming and its influence on the hydrologic cycle—

earlier snowmelt, increased evapotranspiration, and drier soils (Garfin et al. 2013). 

• Intensified heat waves, droughts, and wildfires by 2050 caused by climate change (Lukas 

et al. 2014). 

1.1.4 A Note about Climate Variability

Natural climate variability strongly influences climate and weather extremes. Even under a 

severe climate change scenario, climate variability will continue to influence interannual to 

interdecadal changes in climate, weather, and associated climate extremes.

In the Intermountain West, natural climate variability is modulated primarily by processes that 

are related to the ocean circulation on interannual, interdecadal, and multidecadal timescales and 

accompanying atmospheric teleconnections. These include the following phenomena: 

• The El Niño Southern Oscillation. This large-scale ocean-atmosphere climate 

interaction is linked to a periodic warming in sea surface temperatures across the central 

and east-central equatorial Pacific. 

• The La Niña Southern Oscillation. This represents periods of below-average sea 

surface temperatures across the east-central equatorial Pacific.

• The Pacific Decadal Oscillation. This robust, recurring pattern of ocean-atmosphere 

climate variability is centered over the midlatitude Pacific basin. 

• The Atlantic Multidecadal Oscillation. This ocean current with different modes on 

multidecadal time scales affects the North Atlantic Ocean, especially sea surface 

temperatures. 
4 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Colorado tends to be drier in years that combine a La Niña, a negative Pacific Decadal 

Oscillation, and a positive Atlantic Multidecadal Oscillation. 

Scientists currently cannot accurately predict these phenomena at yearly to decadal timescales or 

understand how they are affected by climate change. For example, scientists do not yet know 

whether Colorado will experience more frequent or intense El Niño or La Niña events because of 

climate change. Therefore, interannual and interdecadal climate changes are uncertain.

1.2 NREL’s Climate Change Resiliency and Preparedness Project 

DOE has been formally planning for climate change at a national level since 2011. Its efforts 

include adding climate change as an integral part of its 2014–2018 Strategic Plan (DOE 2014b), 

creating a Climate Change Adaptation Planning Work Group, and producing an agency-wide 

Climate Adaptation Plan (DOE 2014a). 

DOE is also working to better understand how its sites can become more resilient to changes in 

climate. As part of the Fiscal Year 2015 Site Sustainability Plan that each DOE site must submit, 

DOE has requested that each site complete the DOE Climate Change Adaptation Screening 

Assessment to assess historical climate impacts and any adaptation strategies that have been 

implemented. DOE’s Sustainability Performance Office has supported pilot projects at four of 

DOE’s sites—NREL, Idaho National Laboratory, Pacific Northwest National Laboratory, and 

the Thomas Jefferson National Accelerator Facility—for climate change adaptation site 

planning. The Sustainability Performance Office will use the lessons learned from these pilot 

projects to provide adaptation planning guidance for other DOE sites. 

NREL launched its CCRP project in summer 2014. The project has two stages: (1) a 

vulnerability assessment to identify how climate change could affect NREL’s ability to meet its 

mission, and (2) a resiliency action plan to explore adaptation options to enhance NREL’s 

resiliency to climate change. The remainder of this report discusses the vulnerability assessment.
5 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

2 Vulnerability Assessment

The ultimate goal of the vulnerability assessment was to identify NREL’s highest risk 

vulnerabilities to climate change so that the project team could evaluate relevant resiliency 

options. To accomplish this, the project team worked sequentially to: 

• Create an impacts framework to help identify potential vulnerabilities. 

• Develop risk-based scores for NREL’s potential vulnerabilities.

• Identify NREL’s highest risk vulnerabilities.

An important aspect of the work on the vulnerability assessment was periodic input and guidance 

from the NREL CCRP steering committee. The committee, which first met before NREL hired 

Abt Environmental Research, consists of representatives from across the laboratory. 

2.1 Creating an Impacts Framework

The climate change impacts framework, which was developed as the first step in identifying 

NREL’s potential climate change vulnerabilities, consisted of three key objectives and six key 

resources that were used to identify NREL-specific climate change vulnerabilities. This approach 

was selected based on feedback and input from the steering committee. 

The impacts framework and the guiding questions it generated helped the project team to 

conduct a comprehensive review of NREL’s potential climate change vulnerabilities through 

interviews with staff work groups, or focus groups, which are described in the following 

sections.

2.1.1 Identify Key Resources and Objectives

To develop the impacts framework, the project team first identified NREL’s key resources and 

organizational objectives. The key resources were selected during extensive discussions about 

the operations, practices, and procedures that NREL commonly employs to conduct its work. 

These resources are essential to the continued operation of NREL’s facilities and research areas. 

The project team also identified NREL’s key objectives—the laboratory’s mission-critical areas 

of work—based on NREL’s 2014 Annual Plan and Performance Evaluation and Measurement 

Plan (PEMP) goals (NREL 2014). The PEMP is a resource for identifying key organizational 

objectives because it is a guiding document for meeting annual DOE goals.

The following three key objectives were identified, with associated Fiscal Year 2014 PEMP 

goals listed as subbullets:

1. Execute research, analysis, and deployment 

o PEMP Goal 1.0—Advancing Science and Technology 

o PEMP Goal 4.0—Credible and Objective Analysis and Decision Support 

o PEMP Goal 5.0—Accelerating Commercialization and Increasing Deployment

2. Deliver facility stewardship 

o PEMP Goal 2.0—Stewarding Major Research Facilities
6 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

3. Sustain laboratory operations 

o PEMP Goal 6.0—Environment, Safety, and Health Management

o PEMP Goal 7.0—Business Operations

o PEMP Goal 8.0—Infrastructure Development and Site Operations 

o PEMP Goal 9.0—Security and Emergency Management.

Table 1 shows the final list of key resources and objectives that informed the vulnerability 

assessment effort.9

Table 1. Impacts Framework

Key Objectives

Key Resources

Water Energy Physical 

Space

Site 

Access Workforce 

Research 

and 

Mission

1. Execute research, 

analysis, and 

deployment 

2. Deliver facility 

stewardship

3. Sustain laboratory 

operations

2.1.2 Develop Questions To Uncover Potential Vulnerabilities

The matrix format of Table 1 provided a structure for developing 38 questions that guided 

interviews with NREL staff work groups. These questions aimed to explore the role that climate 

factors played in meeting the three key objectives across each of the six key resources. (See 

Appendix E for the complete list of questions.) 

2.2 Identifying NREL’s Potential Vulnerabilities

Five in-person work group interviews with small groups of NREL staff were conducted to 

identify a comprehensive list of NREL’s potential vulnerabilities associated with climate change. 

The participants were selected and grouped based on their depth of expert knowledge about 

NREL systems: their diverse perspectives, expertise, interests, and backgrounds. The work group 

discussions involved a brief project overview, a review of projected climate changes for the 

Colorado Front Range (Appendix B), and the aforementioned list of guiding questions, which 

flowed from the impacts framework. The work group discussions focused on identifying and 

ranking potential climate-related vulnerabilities in specific areas at NREL:

 

9

For clarity and ease moving forward into the resiliency action plan stage of the CCRP effort, some categories of 

potential vulnerability that were initially approached as belonging to separate key resources were combined. For 

example, water and heating, ventilating, and air conditioning (HVAC) now appear together as Section 2.2.1 and 

concerns about workforce redundancy during emergencies were incorporated into Section 2.2.3. Similarly, 

participants discussed at length an additional key resource that was loosely translated as NREL’s research and 

mission. Given the strong focus of the discussions, this additional key resource has been included to ensure its 

consideration as an area of potential vulnerability; see Section 2.2.6.
7 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

• Building operations 

• Facilities/building area engineers (BAEs)

• Laboratory operations

• National Wind Technology Center (NWTC) operations 

• Researchers and analysts

• South Table Mountain (STM) site operations. 

The staff work group discussions were used as the basis for identifying NREL’s potential 

climate-related vulnerabilities by key resource. A method established by the U.S. Environmental 

Protection Agency’s Climate Ready Estuaries Program (EPA 2013) was used to conduct a risk 

analysis to discern NREL’s highest risk vulnerabilities to climate change. 

The risk analysis considered the magnitude of the consequences of potential vulnerabilities for 

NREL’s key resources, should the potential vulnerability occur (see Box 1) and the likelihood 

that climate variables associated with the potential vulnerability will change (see Box 2). The 

risk analysis culminated by combining the magnitude of consequence score with the likelihood 

score to determine a risk score for each climate variable and, finally, an overall risk score for 

each vulnerability (see Box 3). 

Sections 2.2.1 through 2.2.6 present highlights from the risk analysis for the vulnerabilities 

identified, together with a detailed table. The narrative focuses only on the consequence and 

likelihood scores that ultimately led to an overall risk score of medium-to-high or high (bolded). 

The tables in each section provide details about the consequences, likelihoods, risks, and overall 

risk scores.
8 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Box 1. Scoring Potential Vulnerabilities by Their Magnitude of Consequence

A consequence score was determined for each potential vulnerability; consequence was defined as its 

impact on the key resource, should the potential vulnerability occur, as measured against the three key 

objectives described in Section 2.1. 

The team considered the following five categories of consequence: 

• The effect on internal operations, including the scope and duration of service interruptions, 

reputational risk, and the potential to encounter regulatory problems

• The effect on capital and operating costs, including all capital and operating costs and revenue 

implications caused by the climate change impact

• The number of NREL staff affected

• The health effects on NREL staff, including worker safety

• The environmental effects, including the release of toxic materials, effects on biodiversity, 

changes to the area’s ecosystem, and impacts on historic sites. 

The categories considered when assigning a high, medium, or low consequence score were:

• Low magnitude of consequence. The three key objectives would either experience no major 

effect, or an in-place backup system could cover the failure. 

• Medium magnitude of consequence. The three key objectives would be somewhat affected.

• High magnitude of consequence. The three key objectives would be significantly affected. 

For example, NREL depends on water across the organization, but each site relies on a single 

water provider. Service interruptions would hinder almost every staff member’s work and have 

serious implications for NREL’s ability to achieve Key Objectives 1 and 3.

Box 2. Scoring Climate Variables by the Likelihood of Change

Climate experts from the Western Water Assessment assigned a score for the likelihood that specific 

climate variables will change based on current projected climate changes for the Front Range (Table 

2). A variable was assigned a higher likelihood of occurrence if the climate models demonstrated 

strong agreement about its direction and degree of change. A variable was assigned a lower likelihood 

of occurrence if the models showed less agreement. In addition to the typical scores of low, medium, 

and high, the climate experts on the project team included low-to-medium and medium-to-high.
9 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Table 2. Climate Variables of Concern and Associated Likelihood of Changing

Colors indicate the likelihood of change, from red (high likelihood)

through yellow (low likelihood)

Climate Variable Likelihood 

Increased annual average temperatures

Increased extreme heat events

Earlier peak stream flows

Increased likelihood of fire and longer fire season

Increased minimum nighttime temperatures

High

Increased intensity of summer rainfall

Increased intensity of winter storms

Increased drought intensity

Increased evapotranspiration

Changes in lightning patterns and longer lightning seasons

Reduction in late summer stream flow 

Reduction in raw water quality

Higher particulate loading

Increased intensity of storm events

Medium-to-high

Increased pollen count

Landslides Medium

Increased likelihood of ice storms Low-to-medium

Shifts in annual and seasonal precipitation amounts

Changes in total annual stream flows

Changes in wind patterns

Low
10 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Box 3. Scoring Each Potential Vulnerability for Risk and Overall Risk

The final step in scoring each potential vulnerability was to assess it for risk; the risk score was a 

combination of the consequence score (Box 1) and the climate variable likelihood score (Box 2). At this 

point the vulnerability is no longer referred to as “potential” because the risk score or overall risk score 

can be used to categorize vulnerabilities into highest risk vulnerabilities and lower tier vulnerabilities. 

Some low-risk vulnerabilities may not be worthy of further consideration. Most potential vulnerabilities 

were associated with more than one climate variable. Thus, a risk score was assigned to each 

vulnerability/climate variable combination; those risk scores were then used to determine an overall risk 

score for each vulnerability, irrespective of the specific climate variable.

A risk score matrix was used to develop a risk score for each potential vulnerability/climate variable 

combination to define a risk score of low, low-to-medium, medium, medium-to-high, or high (Figure 1). 

The consequence and likelihood scores were then averaged to establish a risk score for each 

vulnerability/climate variable combination. When a score fell between two possible rankings, the higher 

of the two scores was used to determine a risk score. For example, a potential vulnerability that 

received a high consequence and a low-to-medium likelihood score received a medium-to-high risk 

score. 

The risk scores associated with each vulnerability/climate variable combination were compared to 

determine an overall risk score for each vulnerability; the highest risk score for that vulnerability was 

selected. Climate variables were not prioritized. For example, if a vulnerability was associated with 

three climate variables, and the risk score associated with two ranked as a low-to-medium risk and one 

as a medium-to-high risk, the overall risk was ranked medium-to-high.

Vulnerabilities that received a medium-to-high or high overall risk score are considered further in the 

resiliency action plan. Vulnerabilities that received a medium overall risk score would be good 

candidates to consider in a subsequent round of the resiliency action plan. Vulnerabilities that received 

a low or low-to-medium overall risk score should be monitored over time but do not require immediate 

action.

Figure 1. Risk score matrix

2.2.1 Water 

Water is an essential resource for the STM and NWTC sites. The STM site consumes 

approximately 20 million gallons of water annually. The end uses of water are broken down as 

follows: domestic (35%), cooling systems (30%), evaporative cooling (15%), irrigation (10%), 

research (5%), and leakage (5%). The two most significant water-related vulnerabilities 

identified were NREL’s reliance on a single water supplier for each campus and its use of 

evaporative cooling and chillers. The Consolidated Mutual Water Company provides water to 

the STM through a piping system. One independent supplier delivers water to the NWTC by Consequence High Medium Medium-to-high Medium-to-high High High

Medium Low-to-medium Medium Medium Medium-to-high Medium-to-high

Low Low Low-to-medium Low-to-medium Medium Medium

Low Low-tomedium Medium Medium-tohigh High

Likelihood 
11 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

truck. The water is stored onsite in short-term storage tanks. NREL does not have the capacity 

for significant backup supply at either site and Colorado water law prohibits the retention of 

rainfall and reuse of water resources. Water supply ranked as a high-consequence vulnerability, 

and evaporative cooling and chillers ranked as a medium-consequence vulnerability because of 

their importance to Key Objectives 1 and 3, laboratory research and operations. 

Climate experts scored seven climate variables that can affect water supply with a medium-tohigh or high likelihood: 

• Earlier peak stream flows, which could mean less water is available in late spring and 

summer

• Reduced late summer stream flows, which could also lead to water shortages in late 

summer and fall

• An increase in the intensity of summer rainfall, which could lead to flooding events that 

impair water quality or damage the water supply infrastructure

• An increase in the intensity of winter storms, which could lead to water supply 

infrastructure failure

• An increase in drought intensity, which could increase water demand and put pressure on 

NREL’s single water suppliers for each campus 

• An increase in evapotranspiration, which could lead to greater passive loss of water 

supplies and consequent water shortages

• An increase in fires and fire season length, which could lead to water supply disruption 

because of reservoir sedimentation and water quality impairment.

Climate experts scored one climate variable that can affect evaporative cooling and chillers with 

a high likelihood: an increase in average annual temperature, which could reduce the efficiency 

and effectiveness of evaporative cooling and chillers.

Because of their risk scores, water supply has an overall risk score of high and the reliance on 

evaporative cooling and chillers has an overall risk score of medium-to-high. Table 3 provides 

full details about the consequence, likelihood, risk, and overall risk scores for water.
12 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Table 3. Water: Consequence, Likelihood, Risk, and Overall Risk Scores*

Vulnerability Consequence Climate Variable Likelihood Risk Score Overall Risk 

Score

Each campus has only one 

water supplier and no 

backup options

High

Earlier peak stream flows High High

High

Changes in total annual stream flows Low Medium

Reduced late summer stream flows Medium-to-high High

Increased intensity of summer rainfall Medium-to-high High

Increased intensity of winter storms Medium-to-high High

Shift in annual and seasonal 

precipitation amounts Low Medium

Increased drought intensity Medium-to-high High

Increased evapotranspiration Medium-to-high High

Increased likelihood of fire and longer 

fire season High High

NREL may not be able to 

continue to rely on 

evaporative cooling and 

chillers

Medium Increased annual average 

temperatures High Medium-to-high Medium-to-high

The need for high-quality 

water for certain research 

areas may not be met

Low

Reduced raw water quality Medium-to-high Medium 

Medium

Reduced late summer stream flows Medium-to-high Medium

Increased likelihood of fire and longer 

fire season High Medium

Increased intensity of summer rainfall Medium-to-high Medium 

Higher particulate (sediment) loading Medium-to-high Medium 

*

See Box 1, Box 2, and Box 3 for details about scoring methodology.
13 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

2.2.2 Energy

NREL needs a consistent and reliable energy supply. Although thermal energy is used for 

heating, it is not a substantial risk because NREL has on-site renewable resources and additional 

capabilities to source natural gas. However, all of NREL’s information technology (IT) 

infrastructure, its buildings, and its research areas depend on a reliable source of electricity. 

From renewable energy technologies such as photovoltaic (PV) cells and wind turbines, NREL 

produces the equivalent of approximately 20% of the electricity that it uses. However, NREL 

receives the majority of its electricity from the Xcel Energy electricity grid and does not 

currently have the capacity to use on-site renewable power in the event of a grid power outage. 

NREL relies on the grid to distribute and provide the base load of campus power. 

NREL depends on a single electricity supplier for its electricity. It has only enough diesel 

generator backup capacity to maintain emergency operations and shut down processes. If 

NREL’s electricity supply were compromised, it could face serious consequences to its research 

and compromise worker safety. All of NREL’s IT infrastructure would also be compromised, so 

staff would not be able to access NREL’s networks remotely. Because a stable electricity supply 

is critical to NREL’s research and operations (Key Objectives 1 and 3), a single electricity 

supplier ranked as a high-consequence vulnerability. 

Climate experts scored six climate variables that can affect NREL’s energy supply with a low-tomedium,10 medium-to-high, or high likelihood: 

• An increase in average annual temperatures, which could reduce the efficiency of 

electricity transmission and increase electricity demand

• An increase in the intensity of summer rainfall, which could lead to flooding events that 

could damage the energy supply or transmission infrastructure 

• An increase in the likelihood of ice storms, which could damage the energy supply or 

transmission infrastructure

• An increase in the intensity of winter storms, which could damage the energy supply or 

transmission infrastructure

• An increase in lightning patterns and a longer lightning season, which could damage the 

energy supply or transmission infrastructure 

• An increase in fires and fire season length, which could damage the energy supply or 

transmission infrastructure.

Because of its risk scores, having a single electricity supplier has an overall risk score of high. 

Table 4 provides full details about the consequence, likelihood, risk, and overall risk scores for 

energy. 

 

10For this vulnerability, a low-to-medium likelihood climate variable was included because, associated with the 

high-consequence score, it leads to a medium-to-high risk score.
14 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Table 4. Energy: Consequence, Likelihood, Risk, and Overall Risk Scores*

Vulnerability Consequence Climate Variable Likelihood Risk Score

Overall 

Risk 

Score 

NREL has only one 

electricity supplier and 

depends on energy to 

support mission-critical 

activities, including IT 

connectivity

High

Increased annual average temperatures High High

High

Increased intensity of summer rainfall Medium-to-high High

Increased likelihood of ice storms Low-to-medium Medium-to-high

Increased intensity of winter storms Medium-to-high High

Changes in lightning patterns and longer 

lightning seasons Medium-to-high High

Increased likelihood of fire and longer 

fire season High High

Changes in wind patterns Low Medium

* See Box 1, Box 2, and Box 3 for details about scoring methodology
15 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

2.2.3 Physical Space

NREL relies on physical space11 to achieve Key Objectives 1, 2, and 3. Office space, research 

laboratories, and research equipment, including chemicals and other materials stored outdoors, 

are critical to NREL’s operations. NREL’s physical space is constantly exposed to climate and is 

inherently affected by climate changes. Thus, consequence scores were assigned to known 

concerns that already affect NREL’s physical space: landslides may occur because the STM 

buildings are close to the mesa slope, which scored high consequence for potential landslides; 

the potential for site flooding, which scored medium consequence, given that site flooding may 

occur because of poor drainage; and because damage to climate-sensitive equipment may 

disrupt research,

12 which scored medium consequence. 

Climate experts scored two climate variables that could affect the STM buildings, given their 

proximity to the mesa slope and the possibility of landslides, with a medium or medium-to-high 

likelihood: 

• An increase in the intensity of summer rainfall, which could saturate soils and increase 

the chance of a landslide

• An increase in fires and fire season length, which could denude the mesa slope of 

vegetation and increase the chance of landslides.

Climate experts scored two climate variables that can affect the STM, given poor drainage, with 

a medium-to-high likelihood: 

• An increase in the intensity of summer rainfall, which could overwhelm the designed 

drainage capacity at both campuses

• An increase in the intensity of winter storms, which could overwhelm the designed 

drainage capacity at both campuses, especially in the case of fast snowmelt.

Climate experts scored seven climate variables that can affect research equipment, given its 

sensitivity to climate, with a medium-to-high or high likelihood: 

• An increase in average annual temperatures, which could reduce the effectiveness of 

some outdoor equipment or render it inoperable 

• An increase in extreme heat events, which could reduce the effectiveness of some 

outdoor equipment or render it inoperable 

• An increase in the intensity of summer rainfall, which could lead to flooding that would 

damage outdoor equipment or render it temporarily inoperable 

• An increase in the intensity of winter storms, which could damage some outdoor 

equipment or render it temporarily inoperable 

 

11Physical space is defined as NREL’s land, campus buildings, materials and equipment, facilities, and site 

infrastructure.

12Although DOE regularly assesses the condition of NREL’s equipment, which is documented in the Condition 

Assessment Information System, climate-related concerns are currently not considered in the Condition Assessment 

Information System process. 
16 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

• An increase in lightning patterns and a longer lightning season, which could damage 

some outdoor equipment or render it temporarily inoperable, particularly at the NWTC

• An increase in fires and fire season length, which could disrupt research and damage 

outdoor equipment 

• An increase in minimum nighttime temperatures, which could disrupt research and affect 

outdoor equipment. 

Because of its risk scores, the following overall risk scores were assigned for physical space: the 

potential for landslides because the STM buildings are close to the mesa slope (high); the 

potential for site flooding because of poor drainage (medium-to-high); and potential disruptions 

to research because of equipment sensitivity to climate (medium-to-high). Table 5 provides full 

details about the consequence, likelihood, risk, and overall risk scores for physical space. 
17 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Table 5. Physical Space: Consequence, Likelihood, Risk, and Overall Risk Scores*

Vulnerability Consequence Climate Variable Likelihood Risk Score Overall Risk 

Score

Landslides may occur 

because the STM buildings 

are close to the mesa slope

High

Increased intensity of summer rainfall Medium-to-high High

High Increased likelihood of fire and longer fire season High High 

Site flooding may occur 

because the STM has poor

drainage

Medium Increased intensity of summer rainfall Medium-to-high Medium-to-high Medium-to-high Increased intensity of winter storms Medium-to-high Medium-to-high

Damage to climate-sensitive 

equipment may disrupt 

research

Medium

Increased annual average temperatures High Medium-to-high

Medium-to-high

Increased extreme heat events High Medium-to-high

Increased intensity of summer rainfall Medium-to-high Medium-to-high

Increased intensity of winter storms Medium-to-high Medium-to-high

Changes in lightning patterns and longer lightning 

seasons

Medium-to-high Medium-to-high

Increased likelihood of fire and longer fire season High Medium-to-high

Changes in wind patterns Low Low-to-medium

Increases to minimum nighttime temperatures High Medium-to-high

NREL may not be able to 

continue to use ambient air 

for temperature control in 

many facilities (RSF, ESIF, 

laboratory stations and highbay laboratories at the 

NWTC)

Low

Increased annual average temperatures High Medium

Medium

Increase in extreme heat events High Medium

Changes in relative humidity Medium-to-high Medium

Increased intensity of winter storms Medium-to-high Medium

Increased likelihood of fire and longer fire season High Medium

Changes in wind patterns Low Low

Increased pollen count Medium Low-to-medium

* See Box 1, Box 2, and Box 3 for details about scoring methodology.

ESIF: Energy Systems Integration Facility

RSF: Research Support Facility
18 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

2.2.4 Site Access 

Site access to the STM and NWTC campuses—both physical access to and within NREL sites 

via roadways, and remote access via IT connectivity—is critical for meeting all three of NREL’s 

key objectives. This key resource is distinct from physical space.

Physical site access. Staff and delivery personnel access the NREL campuses via three entrances 

at the STM and one entrance at the NWTC. Some NREL staff members need to be onsite either 

all or part of the time to conduct their work. Depending on the job function, analysts must be 

onsite at least 5% of the time and research-intensive staff must be onsite at least 50% of the time. 

Site operations staff need to be onsite a greater percentage of the time; as many as 40% of site 

operations staff need to be onsite at all times. However, site operations staff represent only 4% of 

the total NREL population. 

Although most of NREL’s staff can work remotely, especially for short periods, key staff must 

have access to NREL’s sites to respond to emergencies and conduct research. This is 

particularly important because the lack of staff redundancy is an issue at NREL. Given the 

importance of physical access to NREL’s research and operations (Key Objectives 1 and 3), this 

vulnerability scored as a medium-to-high consequence. 

IT connectivity. Remote connection to NREL is also essential, both onsite and to enable NREL 

staff to work remotely. NREL’s data center is not cloud-based; a power outage would prevent 

staff from accessing data and connecting with one another (Section 2.2). 

Climate experts scored five climate variables that can affect key staff access to NREL’s sites 

with a medium-to-high or high likelihood: 

• An increase in heat events, which could render working both indoors and outdoors 

untenable 

• An increase in the intensity of summer rainfall, which could lead to more frequent and 

severe flooding and make travel to and around NREL difficult 

• An increase in fires and fire season length, which could make travel to and around NREL 

difficult if roads are closed

• An increase in lightning patterns and a longer lightning season, which could affect NREL 

access, particularly at the NWTC

• An increase in the intensity of winter storms, which could make travel to and around 

NREL difficult.

Because of its risk scores, the inability of key staff to access NREL’s sites was assigned an 

overall risk score of medium-to-high. Table 6 provides full details about the consequence, 

likelihood, risk, and overall risk scores for site access. 
19 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Table 6. Site Access: Consequence, Likelihood, Risk, and Overall Risk Scores*

Vulnerability Consequence Climate Variable Likelihood Risk Score Overall Risk 

Score 

Key staff may not be able to 

access NREL sites to respond 

to emergencies and to 

conduct research; some 

situations may require staff 

redundancy

Medium

Increased extreme heat events High Medium-to-high

Medium-to-high

Increased intensity of summer rainfall Medium-to-high Medium-to-high

Increased likelihood of fire and longer 

fire season High Medium-to-high

Increased lightning patterns and 

longer lightning season 

Medium-to-high Medium-to-high

Increased intensity of winter storms Medium-to-high Medium-to-high

Only one access point is 

available for supply delivery in 

many buildings

Low

Increased intensity of summer rainfall Medium-to-high Medium 

Medium

Increased intensity of storm events Medium-to-high Medium 

Landslides Medium Low-to-medium 

Increased likelihood of fire and longer 

fire season High Medium

Increased likelihood of ice storms Low-to-medium Low-to-medium 

* See Box 1, Box 2, and Box 3 for details about scoring methodology.
20 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

2.2.5 Workforce 

Even without considering climate change, climate inherently affects NREL’s staff: some need to 

conduct outdoor research and other outdoor activities, such as maintenance of outdoor 

equipment, which may be sensitive to climate. This section focuses exclusively on staff’s ability 

to conduct outdoor research. (See Section 2.2.3 for more information about equipment sensitivity 

to climate.) Because this vulnerability may affect all three key objectives if staff cannot conduct 

outdoor research on its campuses, it was assigned a medium consequence score. 

Climate experts scored two climate variables that can affect staff’s ability to conduct outdoor 

research and other outdoor activities with a medium-to-high or high likelihood: 

• An increase in lightning patterns, which could prevent staff from working outdoors for 

periods of time or affect working hours, especially at the NWTC site 

• An increase in extreme heat events, which could prevent staff from working outdoors or 

affect working hours. 

Because of its risk scores, the need to conduct outdoor research and other outdoor activities was 

assigned an overall risk score of medium-to-high (Table 7).

Table 7. Workforce: Consequence, Likelihood, Risk, and Overall Risk Scores*

Vulnerability Consequence Climate Variable Likelihood Risk 

Score 

Overall Risk 

Score 

Staff may not be 

able to conduct 

outdoor research 

and other outdoor 

activities

Medium

Increased lightning 

patterns and longer 

lightning season

Medium-tohighMedium-tohigh Medium-tohigh Increased extreme 

heat events High Medium-tohigh

* See Box 1, Box 2, and Box 3 for details about scoring methodology.

2.2.6 Research and Mission

Several cross-cutting aspects of NREL’s operations, including NREL’s reputation as a leader in 

sustainability and its position in the local community; its various outdoor research areas that are 

exposed to climate, the interconnected nature of NREL’s work and off-campus dependencies, 

and other broad-scale aspects of NREL are vulnerable to the effects of climate change. 

The need for minimum nightly temperatures for certain research areas and sustainable operations 

is NREL’s most significant research- and mission-related vulnerability. It influences NREL’s 

reputation for having a sustainable campus and impacts climate-sensitive equipment (Section 

2.2.3). NREL’s reputation as a sustainable campus was assigned a medium consequence 

because of its importance to fulfilling Key Objectives 2 and 3. 

Climate experts scored one climate variable that can damage NREL’s reputation as a sustainable 

campus with a high likelihood: An increase in heat events, which could reduce the reliability of 

evaporative cooling and affect passive cooling. This may require more energy-intensive forms of 

cooling to maintain a suitable working environment in NREL buildings. Because of its risk 

scores, NREL’s reputation as a sustainable campus was assigned an overall risk score of high. 
21 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Table 8 provides full details about the consequence, likelihood, risk, and overall risk scores for 

research and mission.

Table 8. Research and Mission: Consequence, Likelihood, Risk, and Overall Risk Scoresa

Vulnerability Consequence Climate 

Variable Likelihood Risk Score

Overall 

Risk Score

NREL’s reputation as 

a sustainable campus 

could be damaged

Medium

Increased 

extreme heat 

events

High Medium-tohigh 

Medium-tohigh

The NWTC’s research 

agenda could be 

disruptedb

Low Changes in 

wind patterns Low Low Low

a See Box 1, Box 2, and Box 3 for details about scoring methodology.

b Research at the NWTC would likely be more positively than negatively affected by changes to wind patterns, so 

this vulnerability received a low consequence score.

2.3 Identifying NREL’s Highest Risk Vulnerabilities

After NREL’s vulnerabilities were identified and scored, they were reordered according to the 

associated key resources or climate variables in question (Section 2.2.1 through Section 2.2.6), 

and according to their rank, from high to low. Table 9 summarizes the high-risk and medium-tohigh-risk vulnerabilities, which are addressed by Vogel et al. (2015). 
22 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Table 9. Vulnerabilities with the Highest Overall Risk Score*

Key 

Resource Vulnerability Overall Risk Score 

Water

NREL has only one water supplier for each campus and no backup 

options High

NREL may not be able to continue to rely on evaporative cooling 

and chillers Medium-to-high

Energy NREL has only one electricity supplier and depends on electricity to 

support mission-critical activities, including IT connectivity High

Physical 

space

Landslides may occur because the STM buildings are close to the 

mesa slope High

Site flooding may occur because the STM has poor drainage Medium-to-high 

Damage to climate-sensitive equipment may disrupt research Medium-to-high 

Site access

Key staff may not be able to access NREL’s sites to respond to 

emergencies and conduct research; some situations may require 

staff redundancy

Medium-to-high 

Workforce Staff may not be able to conduct outdoor research and other 

outdoor activities Medium-to-high 

Research and

mission NREL’s reputation as a sustainable campus may be damaged Medium-to-high 

* See Table 3 through Table 8 and Box 3 to understand the reasons these vulnerabilities were assigned an overall 

risk score of medium-to-high or high.

3 Next Stage: The Resiliency Action Plan

Increasing resiliency requires that the vulnerability of NREL’s key resources to climate change 

be reduced. The risk scores for identified vulnerabilities can be lowered by reducing their 

consequences. This is the focus of the resiliency action plan.

To help NREL become more resilient, potential actions will be identified to reduce the 

consequence score for each medium-to-high or high-risk vulnerability. This process will take 

place during the final stage of NREL’s CCRP project, through a series of steps:

1. Categorize the vulnerabilities. Categorize each key vulnerability into one of four 

categories for action: 

o Mitigate risks—take steps to reduce the consequence of the vulnerability.

o Transfer risks—share the vulnerability with another party or insure against it. 

o Accept risks—retain the vulnerability and choose to do nothing. 

o Avoid risks—eliminate the vulnerability by removing the root cause or changing 

organizational goals. 

2. Identify resiliency options. For vulnerabilities that are classified under the “mitigate” 

category, work with key NREL staff to develop a list of resiliency options, including 

those that involve changes to NREL management, operational practices, or infrastructure. 
23 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

3. Prioritize the resiliency options. Evaluate the resiliency options according to a set of 

criteria, including effectiveness, feasibility, and cost. 

4. Develop the resiliency action plan. Synthesize the findings from the process and offer 

actionable resiliency options for NREL as it moves forward with its CCRP project.
24 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Glossary

Adaptation Adjustment in natural or human systems to a new or changing 

environment that exploits beneficial opportunities or moderates 

negative effects (U.S. Global Climate Change Research Program 

(2015). 

Climate The average of weather over some period of time (which can be 

hundreds to thousands of years). The World Meteorological 

Organization standard uses 30 years of weather observations to 

measure climate. A climate can be thought of as the mean and 

variance of weather over 30 years (WMO 2015). 

Climate change Typically denotes a significant change in average conditions but can 

also be the result of a change in variance of weather or in extreme 

weather conditions. 

Climate change impacts Negative or positive effects that changes in climate variables may 

have on human systems. Examples include damage to equipment, 

changes in maintenance cycles, and increased asthma rates.

Climate preparedness Efforts to adapt (prepare) for climate-related effects. Also see 

adaptation and resiliency. 

Climate variables Measurable aspects of climate. Examples include temperature, 

precipitation, wind, humidity, extreme events, drought, and 

flooding. 

Consequence A measure of the impact of a vulnerability on a key resource, as 

measured against key objectives.

Likelihood A measure of the possibility that a climate variable will change.

Resiliency A capability to anticipate, prepare for, respond to, and recover from 

significant multihazard threats with minimum damage to social 

well-being, the economy, and the environment (U.S. Global Climate 

Change Research Program (2015). 

Risk Threats to life, health and safety, the environment, economic wellbeing, etc. Typically evaluated in terms of how likely an event is 

(probability) and the damages that would result (consequences) 

(U.S. Global Climate Change Research Program 2015). 
25 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Vulnerability The degree to which an affected unit (a person, a facility, a 

community, etc.) faces risk from climate. It considers whether the 

unit is exposed to a climate driver and the extent to which the driver 

can affect the unit. A key factor in determining vulnerability is the 

resiliency of the unit. Greater likelihood and consequence increase 

vulnerability; greater resiliency decreases vulnerability.

Weather Typically the climate conditions experienced at a particular point in 

time. It may be the temperature range over a day or a short period, 

precipitation, wind, etc. Thirty years of weather is used to 

statistically define climate.
26 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

References 

Daniels, A.E., Morrison, J.F., Joyce, L.A., Crookston, N.L., Chen, S.-C., and McNulty, S.G. 

2012. Climate Projections FAQ. RMRS-GTR-277WWW. U.S. Department of Agriculture, Fort 

Collins, CO (US). http://efetac4.sref.info/products/publications/Climate_Projections_FAQ.pdf. 

Deems, J., Painter, T., Barsugli, J., Belnap, J., and Udall, B. “Combined Impacts of Current and 

Future Dust Deposition and Regional Warming on Colorado River Basin Snow Dynamics and 

Hydrology.” Hydrology and Earth System Sciences 17 (2013): 4401–4413. 

DOE. 2014a. 2014 DOE Climate Change Adaptation Plan. 

June. www.energy.gov/sites/prod/files/2014/10/f18/doe_ccap_2014.pdf. 

DOE. 2014b. Strategic Plan 2014–2018. U.S. Department of Energy, Washington, DC 

(US). www.energy.gov/sites/prod/files/2014/04/f14/2014_dept_energy_strategic_plan.pdf. 

EPA. 2013. Being Prepared for Climate Change: A Workbook for Developing Risk-Based 

Adaptation Plans. U.S. Environmental Protection Agency, accessed June 5, 

2015. http://www2.epa.gov/cre/being-prepared-climate-change-workbook-developing-riskbased-adaptation-plans. 

Garfin, G., Jardine, A., Merideth, R., Black, M., and LeRoy, S., eds. Assessment of Climate 

Change in the Southwest United States: A Report Prepared for the National Climate Assessment. 

Washington, DC: Island Press, 2013. 

Hansen, J., Nazarenko, L., Ruedy, R., Sato, M., Willis, J., Del Genio, A., Koch, D., Lacis, A., 

Lo, K., Menon, S., Novakov, T., Perlwitz, J., Russell, G.; Schmidt, G.A., and Tausnev, N. 

“Earth’s Energy Imbalance: Confirmation and Implications.” Science 308 (2005): 1431–1435. 

Stocker, T.F.; Qin, D.; Plattner, G.-K.; Tignor, M.; Allen, S.K.; Boschung, J.; Nauels, A.; Xia, 

Y.; Bex V.; Midgley, P.M., eds. Climate Change 2013: The Physical Science Basis. Contribution 

of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate 

Change, Cambridge, United Kingdom and New York, NY, USA: Cambridge University Press, 

2013. 

Lukas, J., Barsugli, J., Doesken, N., Rangwala, I., and Wolter, K. 2014. Climate Change in 

Colorado: A Synthesis to Support Water Resources Management and Adaptation. Second 

Edition. University of Colorado Boulder, accessed March 4, 

2015. wwa.colorado.edu/climate/co2014report/. 

Lüthi, D., Le Floch, M., Bereiter, B., Blunier, T., Barnola, J.-M., Siegenthaler, U., Raynaud, D., 

Jouzel, J., Fischer, H., Kawamura, K., and Stocker, T.F.. “High-Resolution Carbon Dioxide 

Concentration Record 650,000–800,000 Years before Present.” Nature 453 (2008): 379–382. 

Meehl, G.A., Tebaldi, C., Walton, G., Easterling, D., and McDaniel, L. “Relative Increase of 

Record High Maximum Temperatures Compared to Record Low Minimum Temperatures in the 

US.” Geophysical Research Letters 36 23 (2009). 
27 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Melillo, J.M., Richmond, T.C., and Yohe, G.W., eds.. Climate Change Impacts in the United 

States: The Third National Climate Assessment. U.S. Global Change Research Program, 2014. 

doi:10.7930/J0Z31WJ2, accessed March 4, 2015. http://nca2014.globalchange.gov/report. 

NOAA. “Global Ocean Heat and Salt Content.” National Oceanic and Atmospheric 

Administration, 2013, accessed March 4, 

2015. www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/. 

NREL. 2014. Annual Plan and Performance Evaluation and Measurement Plan National 

Renewable Energy Laboratory Rev 2.0. Golden, CO: National Renewable Energy Laboratory.

Vogel, J., Wagner, C., and Renfrow, S. 2015. A Resiliency Action Plan for the National 

Renewable Energy Laboratory. NREL/SR-3500-64175. National Renewable Energy Laboratory, 

Golden, CO. 

Pierce, D.W., Westerling, A.L., and Oyler, J. “Future Humidity Trends Over the Western United 

States in the CMIP5 Global Climate Models and Variable Infiltration Capacity Hydrological 

Modeling System.” Hydrology and Earth System Sciences 17 5 (2013): 1833–1850. 

Seki, O., Foster, G.L., Schmidt, D.N., Mackensen, A., Kawamura, K., and Pancost, R.D. 

“Alkenone and Boron-Based Pliocene pCO2 Records.” Earth and Planetary Science Letters 292 

(2010): 201–211. 

Solomon, S., Plattner, G.-K., Knutti, R., and Friedlingstein, P. “Irreversible Climate Change Due 

to Carbon Dioxide Emissions.” Proceedings of the National Academy of Sciences 106 (2009): 

1704–1709. 

U.S. Global Change Research Program 2015. “Glossary,” accessed June 4, 

2015. http://www.globalchange.gov/climate-change/glossary. 

WMO. 2015. “Frequently Asked Questions.” World Meteorological Organization, accessed June 

4, 2015. www.wmo.int/pages/prog/wcp/ccl/faqs.html. 

Wright, J.S., Sobel, A., and Galewsky, J.. “Diagnosis of Zonal Mean Relative Humidity Changes 

in a Warmer Climate.” Journal of Climate 23:17 (2010): 4556–4569. 

Wuebbles, D., Meehl, G., Hayhoe, K., Karl, T.R., Kunkel, K., Santer, B., Wehner, M., Colle, B., 

Fischer, E.M., Fu, R., Goodman, A., Janssen, E., Kharin, V., Lee, H., Li, W., Long, L.N., Olsen, 

S.C., Pan, Z., Seth, A., Sheffield, J., and Sun, L. “CMIP5 Climate Model Analyses: Climate 

Extremes in the United States.” Bulletin of the American Meteorological Society 95 (2014): 571–

583. 
28 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Appendix A. Climate Change along the Front Range

Author: Imtiaz Rangwala, Western Water Assessment

A.1 Global Climate Change

The global climate system is sensitive to concentrations of long-lived atmospheric GHGs, of 

which the most important is carbon dioxide. The concentration of carbon dioxide, as well as 

several other potent GHGs such as methane and nitrous oxide, has been steadily rising since the 

beginning of the industrial period, but most rapidly since the 1900s. The preindustrial 

concentration of carbon dioxide has been close to 290 ppm, and by 2013 its atmospheric 

concentration reached 400 ppm—a value the Earth’s climate system has certainly not seen in the 

last 800,000 years (based on the longest ice-core record; Lüthi et al. 2008). Based on other proxy 

records, there has not been such a high value in the last five million years (Seki et al. 2010). 

Increases in these GHGs is thought to be the primary factor in causing the recently observed 

radiative imbalance, or additional heat retained in our climate system because of increases in the 

trapping of outgoing infrared emissions from the Earth’s surface by added GHGs of 1 W/m2 at 

the top of atmosphere (Hansen et al. 2005). Most of the additional heat (>90%) retained in our 

climate system is absorbed by oceans, and the rest by the land surface and the atmosphere (IPCC 

2013). This increase in the thermal potential of our climate system is the phenomenon of “global 

warming” (see Figure A-1 for trends in the upper ocean heat content). 

We expect this process to occur based on physical principles, and this understanding has been 

repeatedly confirmed by over 40 years of climate modeling effort, which has become 

increasingly sophisticated during that period. Our climate models predict that the warming of our 

climate system will continue to increase during the 21st century with further increases in 

atmospheric GHG concentrations, and that this warming response primarily depends on the 

future trajectory of anthropogenic, or man-made, GHG emissions. Furthermore, because of the 

long atmospheric lifetimes of gases such as carbon dioxide, it is the total net emission, and not 

the trends in emissions, that will commit us to a particular climate future the next hundreds to 

thousands of years (Solomon et al. 2009). 

A.2 General Circulation Models

GCMs are mathematical representations of the Earth’s climate system (e.g., atmosphere, ocean, 

land surface including vegetation) and processes within it (e.g., atmosphere and ocean 

circulation, precipitation, wind, land surface processes including evapotranspiration). GCMs are 

our primary tools to assess climate response to future changes in the external drivers of our 

climate system, in particular, changes in atmospheric concentrations of GHGs. GCMs have 

improved tremendously in last few decades, and have also become increasingly complex and 

computationally intensive over that time period (see Chapter 3 in Lukas et al. 2014 for more 

detail on GCMs).

We have greater confidence in GCMs for representing large-scale (on the order of 1,000 km) 

systems and processes than we do for them representing smaller spatial scales. This is in part 

because GCMs are currently limited by computational requirements to operate at spatial scales 

smaller than 100 km, thereby inadequately representing finer-scale systems and processes. 
29 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Image source: NOAA (2013)

Figure A-1. Trends in the upper ocean heat content

This is presumably a much better measure of global warming, or additional heat retained 

in the Earth’s climate system, because of increases in anthropogenic GHGs.

For example, for the western United States, these models do not facilitate the actual elevation 

range of the mountain systems or their complex topographical influence on regional and basinscale atmospheric circulation. Because of the coarse resolution at which these models operate, 

mountain systems become smooth and high flat places in these models. For example, in the 

models, the highest elevation in the Colorado Rockies does not reach above 8,000 ft (2,400 m), 

whereas, in reality, the highest point in Colorado is 14,440 ft (4,401 m). 

Furthermore, in part because of the lower elevations of mountain ranges along the West Coast, 

the interior western United States has a strong wet bias—it receives higher modeled precipitation 

than is actually observed. Such a wet bias on a regional scale would influence land surface 

processes, including the nature of temperature response with climate change. Lower-elevation 

gradients in the models also affect important seasonal aspects of the hydrologic cycle in the 

Colorado Rockies. One important example of this is the earlier melting of snowpack because in 

these models snowpack is at a much lower elevation than in actuality. 

Another source of uncertainty for the southwestern United States comes from the inadequate 

representation of the North American monsoon system. Therefore, we have lower confidence in 

future projections for monsoonal-generated precipitation. Furthermore, the warm season 

convective rainfall occurs at sub-grid scales, or spatial scales smaller than the size of a GCM grid 

box, and therefore, it is not physically simulated but rather represented (through a process known 

as parameterization) based on the understanding of certain observed relationships between 

variables such as humidity and air temperature. The choice of methods used for parameterization 

varies among GCMs. These methodological choices and inconsistencies further suppress our 

confidence in future projections related to warm season precipitation as opposed to cold season 
30 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

precipitation, where our understanding of causes is much more traceable and physically 

consistent. 

Furthermore, at regional scales, the inter-GCM projections of future climate have a large range in 

the magnitude of change. For example, they project anywhere from +2.5°F to +5°F increases in 

temperature for Colorado by 2050 for a moderate GHG emissions scenario. For some climate 

variables, such as precipitation, there is also an additional discrepancy associated with the 

direction of change (e.g., models project anywhere from a –5% to a +6% change in annual 

precipitation for Colorado for a moderate GHG emissions scenario).

A.3 Downscaling

To address biases in the GCMs at regional scales and, in certain cases, to improve the simulation 

of regional scale systems and processes within a climate modeling framework, downscaling of 

GCM-derived outputs is performed. Additionally, downscaled data are, in many instances, a 

prerequisite to running the impacts models (e.g., ecosystem response models, hydrologic 

models). Downscaling certainly reduces the GCM biases and better represents the climate of a 

particular region, but it does not reduce the inherent “uncertainties” of GCM projections. In fact, 

the downscaling process can introduce additional errors to the GCM future climate projections. 

More information on downscaling and its relevance to our region can be found in Daniels et al. 

(2012) and Lukas et al. (2014, Chapter 3). 

A.4 Regional Climate Change: Colorado’s Northern Front Range

A.4.1 Observations

The Front Range’s regional climate shows a warming trend in the instrumental record. However, 

most of the warming (>2°F) has occurred in the last few decades, particularly since the mid1990s (Figure A-2). The temperature trend is the same for all of Colorado. This warming is 

plausibly connected to the anthropogenic climate change but it is difficult to make definitive 

attribution at this spatial scale (Lukas et al. 2014). 

Source: Reproduced from Lukas et al. 2014

Figure A-2. Annual temperature departures for the 1913–2012 time period

relative to 1971–2000 average in Colorado’s northern Front Range

Linear trends through 2012 shown by yellow (100-year), orange (50-year),

and dark red (30-year) lines are statistically significant (>97.5%). 
31 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

For annual precipitation amounts, there is no long-term discernable trend either statewide or 

along the Front Range. Similarly, there is no long-term trend in the April 1 snowpack (April 1 

snow water equivalent) in the region although it has been mostly below average since 2000 

across much of the state. Statewide, there are also no shifting trends in heavy precipitation and 

flooding events. There is, however, some evidence that the timing of peak snowmelt and 

associated runoff has shifted earlier by 1 to 4 weeks. This is most likely related to both higher 

spring temperatures and enhanced solar radiation absorption from the dust-on-snow phenomenon 

(Lukas et al. 2014). 

The statewide trend in the Palmer Severity Drought Index depicts increases in soil moisture 

drought conditions in last 30 years, reflecting combined effects of below-average precipitation 

since 2000 and increases in temperature. The anthropogenic climate change may have increased 

the severity of the recent drought events. Nonetheless, tree-ring records going back 1,000 years 

or more show multiple droughts before 1900 that were more severe and sustained for a longer 

duration (Lukas et al. 2014). 

A.5 Projections

Projections of future climate responses are dependent on the atmospheric GHG concentration 

trajectory.13 By 2050, statewide temperatures are projected to increase by +2.5°F to +5°F relative 

to the 1971–2000 period under a moderate emissions scenario (RCP 4.5), and by +3.5°F to 

+6.5°F under a high emissions scenario (RCP 8.5) (Lukas et al. 2014). 

For annual precipitation, the models do not agree on the sign of change, and project a –5% to 

+6% change by 2050 under a moderate emissions scenario (RCP 4.5), and –3% to +8% under a 

high emissions scenario (RCP 8.5). However, nearly all projections indicate increases in winter 

precipitation. Responding to projections in precipitation and temperature, April 1 snow water 

equivalent in the Front Range is projected to change between –20% and +10%. 

For stream flow projections in the Front Range, there is an even chance of increases and 

decreases in annual natural stream flow. However, there is a greater agreement among models 

that peak spring runoff will shift early by 1 to 3 weeks by 2050. This also causes late summer 

and early autumn runoff to decrease (Lukas et al. 2014). Another process that affects this peak 

runoff is dust-on-snow, which, in extreme dust years such as 2009 and 2013, could have shifted 

peak spring runoff 6 weeks earlier (Deems et al. 2013). The combination of increased 

temperature and dust-on-snow could further augment the impact on runoff. 

A.6 Extremes

Extreme events, such as heat waves, severe drought, heavy precipitation, and winter storms, and 

associated consequences generally have a much greater impact on socioeconomic and ecosystem 

structures and functionality. Our understanding of how many of these climate extremes will 

change is still somewhat limited (see Figure A-3) because of the underlying complexity 

associated with the interplay of processes and conditions that drive these extremes. 

 

13However, by the mid-21st century the influence of choosing a particular emissions pathway is smaller than the 

inter-GCM range on a specific climate projection.
32 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Source: Reproduced from Wuebbles et al. (2014)

Figure A-3. One rendition of our current understanding and detection of changes 

in different climate and weather extremes because of climate change 

We have a greater confidence in projections of extremes that are more strongly influenced by 

temperature such as heat waves. We expect increases in the frequency of more intense heat 

waves in the future (Lukas et al. 2014). We are already finding that the frequency of new recordhigh temperatures have doubled in relation to new record-low temperatures for the United States 

as a whole, whereas in the absence of climate change, the ratio should be one-to-one. Climate 

models predict that the ratio of new record-high temperatures to record-low temperatures will 

continue to increase sharply during the 21st century (Meehl et al. 2009). 

Models also project that a greater proportion of future precipitation will be received from the 

heaviest precipitation events because of climate change (Wuebbles et al. 2014). This is in part 

related to increases in moisture and energy associated with individual storm systems. Although 

based on observations in Colorado there is no discernable evidence of this trend; other parts of 

the United States and world show increases in the frequency of very heavy precipitation events 

(Melillo et al. 2014). There is also a medium-low confidence that transition from hail to rain in 

the Front Range will result in higher flash flood risk (Garfin et al. 2013). 

Drought is generally expected to intensify because of future warming and its influence on the 

hydrologic cycle (i.e., earlier snowmelt, increased evapotranspiration and drier soils) (Garfin et 

al. 2013). Most climate models project that heat waves, droughts, and wildfires will intensify by 

2050 in Colorado because of climate change (Lukas et al. 2014). 

A.7 Climate Variability

One factor that strongly influences climate and weather extremes is the natural climate 

variability in our climate system which, For the Intermountain West, natural climate variability is 
33 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

modulated primarily by processes related to the ocean circulation on inter-annual, inter-decadal, 

and multidecadal timescales and accompanying atmospheric teleconnections. These include the 

phenomena identified as the El Niño Southern Oscillation, the La Niña Southern Oscillation, the 

Pacific Decadal Oscillation, and the Atlantic Multidecadal Oscillation. In general, Colorado 

tends to be drier in years that combine a La Niña, a negative Pacific Decadal Oscillation, and a 

positive Atlantic Multidecadal Oscillation. 

We also have limited understanding of how these phenomena will be affected by climate change 

(i.e., Will there be more frequent or intense El Niño or La Niña events because of climate 

change?). Nonetheless, even under a severe climate change scenario, climate variability will 

continue to influence inter-annual to inter-decadal changes in our climate and weather, as well as 

associated climate extremes.
34 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Appendix B. High-Level Overview of Projected Climate 

Changes for the Front Range14

B.1 Temperature

• Increase in average temperatures (including nighttime lows)

• Increase in the magnitude and frequency of extreme hot temperatures (i.e., heat waves) 

• Increase in winter minimum temperatures.

B.2 Precipitation

• More precipitation to occur in higher-intensity events (e.g., increased intensity and 

frequency of flooding) 

• More precipitation to fall as rain than snow

• Increase in stream temperatures (from both higher air temperatures and post-snowmelt 

low flows)

• Earlier snowmelt and peak runoff events; longer duration of low-flow periods. 

B.3 Other

• Increase in the intensity and frequency of droughts from higher temperatures 

• Increase in the intensity of storm events

• Decrease in water quality (because of more extreme precipitation events, fires, tree 

mortality, and higher duration of low flows) 

• Changes in lightning patterns (we expect increases in lightning activity and a longer 

lightning season) 

• Increase in fire risk and a longer fire season 

• Changes in wind patterns (although this is as uncertain as the future sign of precipitation, 

in part due to the same cause: changes in large-scale circulation)

• Changes in vector-borne diseases (e.g., West Nile virus) 

• Increases in pollen count and other allergens (e.g., dust)

• Changes in growing seasons (based on temperatures above freezing, but the effective 

growing season is also affected by water stress and heat waves, among other factors).

 

14Appendix B was developed based on the expertise of climate experts at the Western Water Assessment, a National 

Atmospheric and Oceanic Administration Regional Integrated Sciences and Assessments program associated with 

the University of Colorado.
35 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Appendix C. Notable Destructive Weather Events Since 198515

Table A-1. Destructive Weather Events in Colorado Since 1985

Date Event Type Location Deaths

Damage in 

2013 Dollars 

(Millions)

Description 

January 

1987 Wind storm Boulder, Lakewood, Golden 0 $11.5 Widespread residential and infrastructure damage from gusts of 60–100 miles per hour. 

July 1990 Hailstorm Denver metropolitan 

area, Colorado Springs 0 $1,070

Supercell thunderstorm traveled from Estes Park to Colorado 

Springs, passing directly over Denver with large hail. Thousands of 

roofs and cars damaged. Costliest hailstorm in U.S. history.

July 1997 Flood Fort Collins, Sterling 5 $290

Two consecutive days of heavy convective precipitation in and near 

Fort Collins; on July 28 more than 10 inches fell in 6 hours in the 

Spring Creek watershed on the west side of Fort Collins. Resulting 

flash flood on Spring Creek heavily damaged Colorado State 

University and residential areas, and caused 5 fatalities. The 

following day, 13 inches fell on Pawnee Creek near Sterling, causing 

damaging flash flooding there.

October 

1997 Snowstorm

Multiple counties along 

Front Range, and in 

Eastern Plains

9 No data 

available Unavailable

April–May 

1999 Flood

Colorado Springs, 

Manitou Springs, 

Pueblo, La Junta

0 $85 Multiday rain event caused severe flooding on Fountain Creek, 

Monument Creek, and the Arkansas River.

October 

2001–

September 

2002 

Drought Statewide No data 

available $1,600

One of the driest water years on record in all parts of the state, with 

low peak snowpack, extremely low runoff, multiple large wildfires, and 

severe agricultural impacts.

 

15Appendix C was developed based on the expertise of climate experts at the Western Water Assessment, a National Atmospheric and Oceanic Administration 

Regional Integrated Sciences and Assessments program associated with the University of Colorado.
36 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Date Event Type Location Deaths

Damage in 

2013 Dollars 

(Millions)

Description 

June–July 

2002 Wildfire Teller and Jefferson Counties 1 $50

The Hayman Fire burned 138,000 acres and more than 

200 residences, making it the largest wildfire in Colorado history; later 

wildfires have since surpassed it as the most destructive. It ignited 

and spread during severe drought conditions, abetted by several 

periods of high winds. 

March 2003 Snowstorm

Fort Collins, Boulder, 

Denver metropolitan 

area

No data 

available $118

A very strong 3-day upslope snowstorm brought huge amounts of 

snow and blizzard conditions to most of the Front Range and the 

adjacent plains. Storm totals included 32 inches in Denver and 87 

inches in Rollinsville.

December 

2006 Snowstorm Multiple counties No data available

No data 

available

An upslope snowstorm first dropped more than 20 inches on the 

Denver metropolitan area, then shifted east and south, with totals of 

12 to 36 inches in southeastern Colorado and 30 to 48 inches in the 

foothills and mountains of southern Colorado. Strong winds created 

drifts and led to enormous loss of livestock.

May 2008 Tornado, 

hailstorm Windsor 1 $210 An EF3 tornado destroyed 80 homes and damaged 770 others in and around Windsor during a damaging hailstorm.

July 2009 Hailstorm, 

strong winds

Englewood, Arvada, 

Wheat Ridge, 

Lakewood, Brighton

No data 

available $840

A line of severe thunderstorms with damaging winds dropped large 

hail over a swath of the Denver metro area and spawned two weak 

tornadoes.

September 

2010 Wildfire Boulder County 0 $229 

The Fourmile Canyon Fire started after a month of extremely dry 

conditions, on a day with unusually strong winds for early September. 

Most of the 169 homes destroyed were burned on the first day of 

spread. Approximately 6,500 acres were burned, and the city of 

Boulder itself was at risk on September 10.

June 2012 Wildfire Larimer County 1 $114 The High Park fire was ignited by lightning after a very dry winter and 

spring and burned more than 87,000 acres and at least 259 homes.

June–July 

2012 Wildfire

Woodland Park, Manitou 

Springs, Colorado 

Springs

2 $453

The Waldo Canyon Fire burned during severe to extreme drought 

conditions; strong outflow winds from a thunderstorm on June 26 

pushed the fire into the western portion of Colorado Springs, where 

most of the 346 homes destroyed in the fire were lost. More than 

18,000 acres burned. The Waldo Canyon Fire was the most costly 

wildfire in Colorado history.
37 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Date Event Type Location Deaths

Damage in 

2013 Dollars 

(Millions)

Description 

June 2013 Wildfire Black Forest, Colorado 

Springs 2 $293

The Black Forest Fire ignited during moderate drought conditions on 

a red-flag-warning day; temperatures were in the 90s and relative 

humidity was below 10%. The fire rapidly spread through forested 

suburban neighborhoods, destroying 511 homes in all, and burning 

more than 14,000 acres. The Black Forest Fires was the most 

destructive wildfire, in terms of homes lost, in Colorado history.

September 

2013 Flood

Loveland, Lyons, 

Longmont, Jamestown, 

Boulder, Morrison, 

Evans, Colorado Springs

10 $2,000

A near-stationary weather system funneled copious subtropical 

moisture against the Front Range, leading to 1-week rainfall totals of 

10 to 18 inches over a large area. Creeks and rivers from the 

Wyoming border to Colorado Springs flooded, with the worst flooding 

on the Big Thompson River, St. Vrain Creek, Left Hand Creek, and 

Coal Creek. More than 20,000 homes were damaged or destroyed. 

The Front range suffered incredible and widespread damage to civil 

infrastructure—roads, bridges, water conveyance, and water 

treatment.
38 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Appendix D. Vulnerability Work Group Guiding 

Questions

In preparation for the workgroup, we developed the following questions to help you understand 

what type of information we will be soliciting from the discussion. We are not asking you to 

answer these questions in detail prior to the workgroup. However, we ask that you review the 

questions, identify any knowledge gaps, and, if necessary, seek the appropriate information from 

your colleagues prior to the workgroup so that we may maximize our time together. 

In general, this workgroup interview will help us understand: 

• The vulnerabilities of NREL systems to changes in climate 

• The needs and thresholds for your systems, operations, or areas (hereafter referred to as 

“system” or “systems”), above or below which they would face extreme strain (in the 

case of a one-time occurrence) or you would have to rethink the way you do business (in 

the case of a long-term change in trend) 

• How your systems currently interact with weather or natural resources and if that is likely 

to change in the future 

• If there are potential changes to climate that might impact your systems in the future that 

are not currently being considered 

• If you already had to adapt to changes in climate, or if you have already considered 

potential changes to your systems.

E.1 Issues and Concerns 

1. The following have been identified as some of NREL’s key resources (think of a resource 

as an input you need for your systems). Which of these do your systems rely on? For the 

key resources of relevance to your systems, please consider the specific resource 

questions listed below for that resource. 

a. Water 

b. Energy utilities 

c. HVAC

d. Physical space (e.g., land, buildings, storage, facilities, site infrastructure) 

e. Site access (e.g., internet connectivity, external roadways)

f. Workforce. 

2. Are there other key resources we are missing?

E.2 General Questions to Consider

These are questions to consider as you think about the more specific resource questions below.
39 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

1. Overall:

a. Are the systems in good condition? What are the expected lifetimes of the 

systems? Do the conditions of the systems make it more or less likely to handle an 

extreme event? Would upgrading the systems make them more or less likely to 

handle an extreme event?

b. If the systems failed, would there be safety issues? Impacts to mission 

fulfillment? Regulatory impacts? Operating and maintenance impacts? 

2. Are there data gaps and further research needed pertaining to maintaining your systems 

or understanding the risks to your systems? 

3. Are there existing resiliency efforts at NREL other than business continuity planning, 

emergency preparedness planning, and/or sustainable design guidelines that already 

address these issues? In your opinion, how can climate best be integrated into existing 

systems?

4. Are you aware of tools or technologies currently available to address climate change and 

resiliency at NREL, or locally/regionally/nationally?

5. The next phase of our work will be focused on identifying resiliency measures or 

adaptations, but it is still helpful to think of them at this stage. In particular, in the event 

of the resource being compromised, is there an alternate resource or material that would 

provide the functionality for your research? Or, are there other resiliency measures you 

could turn to? 

E.3 Key Resources

E.3.1 Water

Are there components of your systems that depend on water for buildings or equipment 

operations, or for conducting research, etc.? Although there is much uncertainty about how 

precipitation patterns might change in the future, they are likely to change. To fully assess 

possible vulnerabilities, consider what would happen to your systems if there was: 

• Too much water? 

• Too little water?

• Poor water quality?

• A variable water supply? 

1. What are the water supply thresholds of your system, for example: 

a. How many weeks/months/years of severe drought could your systems withstand 

before you would have to enact an emergency procedure or change operations? 

b. What levels of contamination are worrisome in your water supply? 

2. Are there implications to your systems if there are large annual or seasonal variations in 

water supply? 

3. Is water storage available to ensure that adequate supply is available? 
40 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

4. Are there areas of research that depend on water that meet specific quality parameters 

(such as deionized water)?

5. Are there future research areas or planned capital projects that will change water needs 

(such as increased quantity or changed quality requirements)?

6. Which aspects of NREL operations (i.e., specific buildings or functions) would be most 

susceptible to changes in water quantity or quality? 

E.4 Energy Utilities (electricity, gas, solar, wind, and biomass)

Energy supply might be impacted in the future due to a changing climate. For example, hotter 

average temperatures would result in increased cooling degree days and might result in more 

service outages. Hotter average temperatures might also result in a significant increase in utility 

rates. More frequent extreme events might result in more outages, or less reliable service.

1. What research areas or laboratory operations are most dependent on a consistent supply 

of utilities? 

2. What type of utilities do your systems depend on? 

3. Where are they sourced? Do you have multiple suppliers? Are you dependent on external 

sources of utilities?

4. Is the quality of supply a concern? 

5. How long of a utility outage can your systems tolerate? 

6. Do you store any of your utility supply onsite? If so, what are the temperature-related 

storage requirements?

7. What backup systems are in place? If so, how long will those backup supplies last? 

8. Are there future research areas or planned capital projects that will change utility needs 

(e.g., increase quantity or change quality requirements)? 

E.5 Heating, Ventilating, and Air Conditioning 

A changing climate is very likely to have implications for HVAC systems. For example, both 

average and extreme temperatures are rising, which may put additional strain on air-conditioning 

systems, although this also may provide some relief to heating systems in the winter months. 

Extreme precipitation events may cause leaking in ventilation systems. 

1. Which research areas or aspects of laboratory operations depend on consistent 

temperature, air flow, and air quality? Is there a specific concern?

2. Which aspects of research or operations are most vulnerable to prolonged extreme 

temperatures (i.e., have the hardest time coping with or recovering from)? What 

implications are there currently for your HVAC system during periods of extreme heat?

3. In what ways, if any, is your HVAC system unique? 

4. Describe the backup systems for your HVAC system.

5. Are there future research areas or planned projects that will change HVAC needs 

(e.g., increase quantity or change quality requirements)? 
41 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

E.6 Physical Space (land, buildings, storage) 

Climate is an integral part of our physical space. Our land, buildings, and storage are impacted 

by climate every day. For example, NREL’s physical space might be particularly vulnerable to 

changes in climate if increased temperatures result in increased wear and tear on pavements, 

which would have implications for maintenance and budget cycles. Increased extreme events can 

increase the likelihood of damage and changes in precipitation may alter flood patterns and make 

it difficult to access worksites. 

1. What are the space requirements for your area of research or to support your area of 

laboratory operations, including material storage, office, and laboratories? How much 

building vs. land area is required? 

2. Are there outdoor physical space requirements for your systems (e.g., are components of 

your systems stored outdoors)? If so, what are the climate thresholds of concern for them 

(e.g., the amount of moisture that can be tolerated, the amount of heat which would cause 

concern)? 

3. What facilities are most at-risk to flooding? What are the current flood thresholds for 

your building? What aspects of facilities are just outside the current floodplain? What if a 

historic major event was predicted to occur twice as often in the future? 

4. What facilities are susceptible to changes in temperatures (both changes in extremes as 

well as extreme fluctuations between extremes), aside from HVAC needs (this could be 

outdoor research equipment, building material damage, etc.)? 

5. What facilities are susceptible to increases in extreme events (lightning, hailstorms, wind, 

etc.) to your building, research, ability to perform research? 

6. Are there future research areas or planned projects that would change site building and 

land requirements?

E.7 Site Access (including internet connectivity and external 

roadways)

Will changes in climate affect site access, including IT systems and external roadways? For 

example, a wild fire could block the main entrance to your facility, or increased temperatures 

might result in increased strain on your IT systems. 

1. What areas of research or operations require onsite staff? How many staff must be onsite? 

2. What areas of research could be impacted by disruptions to transportation networks (for 

materials, services)? 

3. What kind of events would make accessing the research site impossible? 

4. Are there future research areas or planned projects that will change access requirements? 

E.8 Workforce

Changes in climate are likely to have implications to your workforce. For example, increased 

temperatures can cause heat stress; changes to climate might result in changes to disease vectors, 

especially those borne by insects; extreme events may make it difficult for your workforce to get 

to work; or staff health might be compromised due to decreased air quality. 
42 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

1. How critical is the onsite attendance of your staff to the performance of your work area? 

How much of the work can be performed remotely if needed? 

2. Do you have redundancy in staff critical to performing research or operations? 

3. How long can disruptions/lack of staffing be tolerated before research is impacted?

4. What percentage, if any, of your workforce works outside of the facility? 

5. What does it take to maintain a productive working temperature in your facilities? 

6. Are there planned future research areas or capital projects that will impact staffing?

7. Are there plans in place to address increased disease outbreaks and other health-related 

concerns at a campus level?