On August 9, 2021, the Intergovernmental Panel on Climate Change (“IPCC”) published a summary of the first part of its Sixth Assessment Report, focused on the physical science of climate change (the “Report”). The results: humanity is poised to bust through the 1.5℃ goal by mid-century under virtually all IPCC scenarios considered and to substantially overshoot the 2℃ goal by 2080 without very stringent emissions reductions. In the remainder of this article, we outline the Report’s key findings.
Extreme Weather Events Will Increase, With Stronger Events Seeing the Greatest Upticks
The Report describes an increase in the frequency and intensity of both storms, including major hurricanes, and droughts and notes that it is “virtually certain” that high temperature extremes have become more frequent and intense across the planet. Moreover, these weather events are not only occurring in stand-alone incidents; the number of compound events, such as a heatwave and drought occurring simultaneously, are also on the rise.
The Report finds that these extremes will continue to grow in both frequency and intensity with further warming,which will in turn lead to events “unprecedented in the observational record,” with projected percentage increases greatest for the rarer (i.e., more intense) events. For example, a historical “100-year storm” is no longer something with only a 1/100 chance of happening; and the likelihood of stronger events, such as a “1000-year storm,” is increasing at even faster rates.
“Every Inhabited Region Across the Globe” Is Already Suffering Effects
While the event types may vary by region, the Report includes a set of maps showing that extreme events are increasing across every inhabited region of the planet. The Report predicts that physical climate conditions will continue deteriorating across the globe, as seen by increases in temperature, and in both tropical and sand storms, changes in precipitation patterns, and sea level rise.
Many Changes are “Irreversible for Centuries”
The Report finds that certain climactic changes are effectively locked-in now due to past emissions. The Report states that several such changes are “irreversible for centuries to millennia.” For example, evidence suggests that it is virtually certain that mean sea level will continue to rise, along with ocean acidification and upper ocean stratification. Glacial melt, from both mountain and polar glaciers, and permafrost thaw are also both committed to continue for decades or centuries, with the carbon loss from permafrost thaw irreversible over hundreds of years.
In addition to the grim evidence above, the Report warns that certain tipping points, while low-likelihood events, “cannot be ruled out.” These tipping points, if they do occur, would have extreme impacts on the climate, and the likelihood of such events increases with higher levels of warming. Examples vary but include ice sheet collapse, abrupt ocean circulation changes, certain compound extreme weather events, and forest dieback.
Rapid Change and Cooperation Can Still Limit the Worst Impacts of Climate Change
Despite the dire consequences of inaction, the Report does conclude on a note of hope: we still have part of our “carbon budget” left to meet the goals of limiting climate change, and rapid action can help to achieve this. However, achieving net zero emissions is a requirement to stabilizing global temperature increase, and limiting temperature increase to particular levels means staying within the carbon budget. The Report provides carbon budgets with varying probabilities of limiting warming to 1.5, 1.7, and 2℃ respectively. The Report also highlights the role of non-CO2 GHGs, notably methane and ozone precursors. Given the relatively high warming potential and relatively short lifetime of methane, reductions in methane emissions can have a marked effect in reducing warming in the near-term.
Additionally, the Report highlights the potential for carbon sequestration to help remove atmospheric CO2, as a means either of reaching net zero emissions by compensating for residual emissions, or of achieving negative emissions to reduce warming. Net negative emissions would also likely help to reverse certain other climactic impacts; however, as discussed above, certain changes are likely irreversible for several centuries even under large net negative emissions scenarios.
What is Being Done Now?
There is increasing consensus from governments that stronger action needs to be taken to address climate change. For example, this past June, the G7 endorsed mandating climate disclosures aligned with the Task Force on Climate-related Financial Disclosures. In the United States, the Biden administration has committed to incorporating climate-related concerns across the federal government and enhancing disclosure of climate-related risks.
Pockets of the private sector have also started to voluntarily ramp up their climate-risk management, particularly the financial sector. Many banks have committed to achieving net zero emissions (including emissions associated with the activities they finance) by 2050, with a significant sub-set thereof subscribing to the Net-Zero Banking Alliance. As we have previously discussed, the commitments of those in the financial sector are already having a ripple effect, as companies in search of capital meet with higher levels of climate-related due diligence and expectations.
Entities, both public and private, are also increasingly aware of the intersection of climate impacts with other important topics, such as human rights, biodiversity, and energy and environmental justice. Although the impacts discussed in the Report will have widespread impact — including on infrastructure, ecosystems, and social systems — other reports have explicitly called out that those impacts are expected to be greater for already marginalized communities.
The IPCC Climate Assessment Report cycle is composed of three stages: (1) physical science; (2) impacts, adaptation, and vulnerability; and (3) mitigation (i.e., response options). The working groups associated with the latter two stages are scheduled to publish their reports in 2022. However, how governments and organizations will use the IPCC’s information remains to be seen. The IPCC’s information is meant to provide the scientific clarity needed to develop climate policies, but c
 See Summary for Policymakers, in
Intergovernmental Panel on Climate Change, Climate Change 2021: The Physical Science Basis SPM-18 (V. Masson-Delmotte, et al
. eds. 2021), https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM.pdf
[“IPCC AR6 WGI”]. Note, IPCC has used “shared socioeconomic pathways” (“SSPs”) instead of the previously used Representative Concentration Pathways (“RCPs”); SSPs look at emissions changes similar to RCPs but also factor in certain socioeconomic changes, such as population change, population density, land use, education, etc. Note that the article is largely based on the Summary for Policymakers
, rather than the entire Report.
at SPM-36 to SPM-37.
 See, e.g.
, Exec. Order No. 14008, Tackling the Climate Crisis at Home and Abroad (Jan. 27, 2021), available at https://www.whitehouse.gov/briefing-room/presidential-actions/2021/01/27/executive-order-on-tackling-the-climate-crisis-at-home-and-abroad/
 See, e.g.
, Austin Pierce et al.
, Three Years Into TCFD’s Final Recommendations: Lessons from Implementation in the Financial Sector
, JD Supra(Sep. 16, 2020), https://www.jdsupra.com/legalnews/three-years-into-tcfd-s-final-89696/
 For an overview of some of these interactions, see
Austin Pierce & Corinne Lewis, Human Rights and Environmental Law: The Overlooked Interaction Gains Traction with Climate Change
, 2(2) State Bar of Texas International Law Section – International Newsletter 24 (Summer 2020), https://files.constantcontact.com/cf349dd3701/1b48d9a5-e967-42d0-ba23-0e464a178221.pdf
 See, e.g.
, Summary Findings
2 Fourth National Climate Assessment 24, U.S. Global Change Research Program (2018), available at https://nca2018.globalchange.gov/
About the authors:
Sarah Fortt has spent a decade working with organizations, small and large, public and private, in navigating their relationships and communications with key stakeholders, including their investors, regulators, employees and communities. She regularly works with boards on managing their approaches to corporate governance, crisis management, succession planning and board education. She is the mind behind the creation of V&E’s ESG Taskforce, a novel cross-functional team that works to provide companies with end-to-end solutions for navigating non-financial risks and opportunities, including those relating to climate change, human rights and corporate culture.
Austin Pierce advises clients on all manner of issues regarding sustainability and ESG. The first associate appointed to V&E’s ESG Taskforce, he regularly works with companies on disclosures (both required and voluntary), strategic projects, policy development and implementation, and the assessment and management of ESG risks and opportunities.
Lindsay Hall is a senior associate in the Washington, DC office of Vinson & Elkins and a member of the firm’s Environmental & Natural Resources practice. She advises clients on a wide range of environmental and regulatory matters at issue in project development, mergers and acquisitions, project financings and real estate development. In addition, Lindsay is routinely involved in the permitting of, and defending challenges to, infrastructure and energy development projects.