APS Public Comment to the Department of Energy on the Impact of Greenhouse Gas Emissions

Filed via Regulations.gov

The Honorable Chris Wright
U.S. Department of Energy
1000 Independence Avenue SW
Washington, DC 20024

Re: Notice of Availability:
A Critical Review of Impacts of Greenhouse Gas Emissions on the U.S. Climate

(90 Fed. Reg. 36150)
Docket No. DOE-HQ-2025-0207

Dear Mr. Secretary:

The American Physical Society (APS) — the largest physics membership organization in the United States, representing more than 50,000 members — appreciates the opportunity to provide written comment on the recent Department of Energy (DOE) report titled “A Critical Review of Impacts of Greenhouse Gas Emissions on the U.S. Climate.”

Physics is a core science for understanding Earth’s climate, and our membership encompasses thousands of experts in crucial fields like fluid dynamics, nonlinear and complex systems modeling, gas phase physics and chemistry, radiative transfer, phase transitions, measurement science, computational physics, statistics, and biological physics. APS hosts a dedicated topical group on climate science with nearly 700 members, providing a forum for on-going dissemination and discussion of current climate science research.

Our membership’s varied perspectives and broad expertise inform our policy statements, including our position on Earth’s changing climate. The Society’s deliberative process for generating, creating, and adopting policy statements involves our members, committees, and leadership, including both the APS Council and Board of Directors. Our statement process includes an open comment period for APS members, ensuring that all APS members have the opportunity to provide input. All comments are reviewed to ensure that we are appropriately articulating the position of the physics community.

In developing the current APS Statement on Earth’s Changing Climate, the Society rigorously considered the scientific literature, held exercises explicitly incorporating a wide array of voices, and evaluated all 1,500+ member comments during reviews in 2015 and 2021. The Society’s formal position is shared below.

The conclusions of DOE’s new report are directly at odds with this APS statement and do not represent the consensus of the international scientific community.

Sincerely,

Jonathan A. Bagger

APS Chief Executive Officer

Statement on Earth’s Changing Climate

Effective Nov. 10, 2021

On Climate Change

Earth’s climate is changing.^1,2 This critical issue³ poses the risk of significant environmental,⁴ social,⁵ and economic disruptions⁶ around the globe.

Multiple lines of evidence strongly support the finding that anthropogenic greenhouse gases have become the dominant driver of global climate warming observed⁷ since the mid-twentieth century.⁸

Moreover, the deduction that human-induced alterations to many principal components of the climate system are accelerating is supported by the preponderance of observational evidence.⁹ The potential consequences of climate change are great¹⁰ and the actions taken over the next decade or two¹¹ will determine human influences on the climate for centuries to millennia.¹²

On Climate Science

As summarized in the 2018 and 2019 special reports of the Intergovernmental Panel on Climate Change (IPCC), the empirical, theoretical, and computational foundations of climate science have continually become more robust. These summaries are based upon a detailed evaluation of the evidence and quantified measures of uncertainty for each primary finding.¹³

On the basis of these advances, the IPCC has recently concluded¹⁴ that it is likely¹⁵ that human induced warming¹⁶ has reached 1.0±0.2ºC since the late 19th century. During the 21st century, these estimates of human-induced warming¹⁷ have been equal to the level of observed warming to within +20%.¹⁸

As recognized by prior and forthcoming Assessment Reports of the IPCC, major scientific challenges remain in our abilities to project, adapt to, and mitigate anthropogenic climate change.

To better inform societal choices, the APS urges sustained research in climate science.

On Climate Action 

The APS reaffirms its 2015 call to support actions that will reduce the emissions, and ultimately the concentration, of greenhouse gases as well as increase the resilience of society to a changing climate, and to support research on technologies that could reduce the climate impact of human activities.

Because physics and its techniques are fundamental elements of climate science, the APS urges physicists to expedite collaborations with colleagues across all disciplines in climate research as well as contributions to the public dialogue.

References

1. In revising this statement, the evidentiary basis for statements contained in it has been drawn from reports prepared by the Intergovernmental Panel on Climate Change (IPCC – see https://www.ipcc.ch/). The last major IPCC assessment was issued in 2021. The evidentiary basis for this APS Statement is drawn from both the 2021 IPCC 6th assessment and three Special Reports (SR) of the IPCC issued in 2018 and 2019. The reports are SR1.5 (“Global Warming of1.5 ºC”), SROCC (“Special Report on the Ocean and Cryosphere in a Changing Climate”), and SRCCL (“Climate Change and Land”). Each of these reports are in turn comprised of three sections: a Summary for Policy Makers (SPM), a Technical Summary (TS) from which it is traceably derived, and the full text of the underlying report from which the TS is traceably extracted. The full references for the three Special Reports are, respectively [all URLs checked 10/8/2021]:

• IPCC, 2018: Global Warming of 1.5°C.An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte, V., P. Zhai, H.-O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia, C. Péan, R. Pidcock, S. Connors, J.B.R. Matthews, Y. Chen, X. Zhou, M.I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, and T. Waterfield (eds.)]. URL: https://www.ipcc.ch/sr15/
• PCC, 2019: IPCC Special Report on the Ocean and Cryosphere in a Changing Climate [H.-O. Pörtner, D.C. Roberts, V. Masson-Delmotte, P. Zhai, M. Tignor, E. Poloczanska, K. Mintenbeck, A. Alegría, M. Nicolai, A. Okem, J. Petzold, B. Rama, N.M. Weyer (eds.)]. URL: https://www.ipcc.ch/srocc
• IPCC, 2019: Climate Change and Land: an IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems [P.R. Shukla, J. Skea, E. Calvo Buendia, V. Masson-Delmotte, H.-O. Pörtner, D. C. Roberts, P. Zhai, R. Slade, S. Connors, R. van Diemen, M. Ferrat, E. Haughey, S. Luz, S. Neogi, M. Pathak, J. Petzold, J. Portugal Pereira, P. Vyas, E. Huntley, K. Kissick, M. Belkacemi, J. Malley, (eds.)]. URL: https://www.ipcc.ch/srccl/
• IPCC, 2021: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press. In press. URL: https://www.ipcc.ch/report/sixth-assessment-report-working-group-i/

2. SR1.5 SPM A.1.1 thru A.1.3 – temperatures and extremes; SROCC A.1 – cryosphere; SROCC A.3 – GMSL

3. SR1.5 SPM A.3.1 – “Impacts already observed.”; SROCC A.2 – examples include ocean heat, changes in PH, and loss of oxygen

4. SR1.5 SPM B.3.1 thru B.3.3 on terrestrial ecosystem impacts; B.4.2 thru B.4.4 on ocean ecosystems; SROCC A.4 on cryospheric terrestrial ecosystems; SROCC A.5 and A.6, on marine and coastal ecosystems; SRCCL A.2, on desertification, land degradation, and adverse impacts on terrestrial ecosystems

5. SR1.5 SPM B.5.1 thru B.5.4, B.5.6 – populations at risk, health, food, water stress, compound stresses; SROCC A.7 – societal impacts of shrinking cryosphere; SROCC A.8 – impacts on fisheries; SROCC A.9 – risks to coastal communities; SRCCL A.2

6. SR1.5 SPM B.5.5 – risks to aggregated economic growth; SROCC C1 – Economic disparities in outcomes

7. SR1.5 SPM A.1.1 thru A.1.3 – temperatures and extremes; SROCC A.1 – cryosphere; SROCC A.3 – GMSL

8. SR11.5 SPM A.1.1, Section 1.2.1; SROCC A.2, which states “Since 1993, the rate of ocean warming has more than doubled (likely).”

9. SR 1.5 section 1.2.1.3 – it is likely that most recent warming is anthropogenic

10. See citations above; SROCC section B on projected change– B.1 cryosphere; B.2 temps and AMOC; B.3 GMSL; B.4 land cryosphere; B.5 marine biomass; B.6 coastal ecosystems; B.7 water resources; B.8 fisheries; B.9 societal impacts of GMSL; SRCCL A.5 – climate stresses on land

11. SR1.5 SPM Section C on scenarios, SROCC B.1 (sentence at end, B.2 (sentence at end), C.4 (opening sentences), SRCCL B.7 on positive impacts of land use scenarios; SRCCL D.1 on near-term actions; D.3 on benefits of rapid GHG emissions reductions 12. SR1.5 SPM Section A.2

13. Guidance Note for Lead Authors of the IPCC Fifth Assessment Report on Consistent Treatment of Uncertainties

14. SR1.5 Technical Summary TS.1

15. Guidance Note for Lead Authors of the IPCC Fifth Assessment Report on Consistent Treatment of Uncertainties

16. Global mean surface temperature (GMST)

17. Global mean surface temperature (GMST)

18. SR1.5 Technical Summary TS.1