Environment | Ten Across | Data Viz
The climate is changing. what can we do about it?
Insights from the fifth National Climate Assessment
Editor’s note: This article is part of a collaboration between APM Research Lab and the Ten Across initiative, housed at Arizona State University.
by RITHWIK KALALE | Jan. 18, 2024
2023 was the warmest year on record. It is likely the hottest the Earth has been in the past 125,000 years. According to the latest National Climate Assessment, prepared by the nonpartisan and congressionally mandated U.S. Global Change Research Program, the rapidly increasing global temperatures are accelerating due to man-made climate change.
This NCA, the fifth issued since 2000, details the latest scientific evidence of climate change and addresses how that change impacts our country and world in areas such as agriculture, energy production and use, natural resources, transportation and biodiversity. The assessment also reports established best practices for both adapting and preventing or mitigating further climate change — which we have summarized below.
Adaptation: Reducing risks in a warming climate
Climate change is leading to a variety of changes, including increased flooding in some areas, droughts in others as well as wildfires and loss of coastlines — all of which requires adaptation. While referencing the very real threats that come with climate change, the NCA’s chapter on adaptation notes that effective adaptation strategies can “protect human lives, improve quality of life, enhance social equity, reduce healthcare costs, and safeguard and restore the natural ecosystems on which society depends for its very survival.”
Number of public- and private-sector adaptation activities publicly documented from 2018-2022. Credit: WSP, University of Delaware, and University of California, Irvine.
The report outlines five stages to adaptation: awareness, assessment, policy, implementation and evaluation. While the NCA mentions that strides have been made in the first two areas, it notes only incremental progress toward drafting, implementing and evaluating climate-related adaptation policies, at least at the state level. According to the report, over 20 federal agencies have prepared or updated climate resilience plans, but 32 states still lack a public plan.
The NCA highlights many barriers to achieving progress toward climate adaptation, including “systemic issues such as inequality, discrimination, and limited access to essential resources and opportunities.” For example, the report points out that Indigenous communities living in remote and vulnerable locations often have very limited opportunity to share their opinions, in turn preventing achieving equitable adaptation.
Further, the report notes that justice and equity are rarely considered when drafting adaptation strategies, claiming (with “high confidence”) that “actions that do not explicitly address the uneven distribution of climate harms, and the social processes and injustices underlying these disparities, can exacerbate social inequities and increase exposure to climate harms.”
The report notes that recent federal programs, such as the Biden administration’s Justice 40 initiative, have been developed to address such oversights.
Incremental versus transformative adaptation
The assessment states progress in adaptation strategies have been slow and reflect only minor shifts in practice. These incremental actions affect only small geographic areas or populations but are not significant enough to cause impact on a national, much less global, scale.
The NCA’s authors highlight transformative adaptation strategies, such as redesigning cities and buildings to address heat, shifting water-intensive industry to match new rainfall patterns, and directing new housing development to less flood-prone areas.
The report counterposes the incremental strategy of improving irrigation systems to reduce agricultural water use versus a transformative strategy of reimagining how and where crops are produced, stored and transported across the U. S. Improved irrigation may be easier, but may not sufficiently address the long-term effects of climate change – and therefore may also end up being less cost-effective over the long term.
The implementation of transformative adaptation strategies ultimately requires many organizations and actors to collaborate, from a global level like the United Nations to state-based higher education institutions and other forms of local government.
A final barrier to adaptation outlined in the NCA is funding. According to the report, financing for climate adaptation is limited in the U.S. This is due to a variety of factors, such as high perceived uncertainty costs, lack of incentives for private companies to invest and an unsupportive regulatory environment.
Mitigation: Preventing further climate change
Mitigation refers to measures that reduce or remove carbon from the atmosphere and decrease the effects of climate change altogether. The main mitigation goal highlighted in the NCA’s chapter on mitigation is “limit[ing] global warming to 1.5°C above pre- industrial levels.” For the U.S., this means reaching net-zero emissions by 2050.
Like adaptation strategies, mitigation requires the cooperation of many entities, especially at the state level. Additionally, the size and cost of emissions reductions depend on available technologies and the sources of emissions.
Historical trends in U.S. greenhouse gas emissions from 2005-2019 and future targets. Credit: University of California, Irvine, North Carolina State University, DOS and EOP, 2021: The Long-Term Strategy of the United States: Pathways to Net-Zero Greenhouse Gas Emissions by 2050. U.S. Department of State and U.S. Executive Office of the President, Washington, DC.
The good news, according to the NCA, is that strategies are already in place to drastically reduce emissions in the country. One example is the movement toward decarbonizing electricity, made possible by growing policy support for renewable energy.
Land-related emission reduction is another mitigation strategy that the report claims can be effective. Examples of this include restricting agriculture to only the most productive land, campaigns to reduce food waste (the NCA reports that currently 40% of food is wasted in the U.S. annually), and a wider diet shift away from more carbon-intensive meat products.
The NCA also notes that carbon capture can be an important mitigation strategy, especially for sectors that are difficult to decarbonize, such as aviation.
The NCA applauds many steps that the U.S. has taken toward climate change mitigation, including committing to the Paris Agreement to reduce green house gas emissions by at least 50% from 2005 to 2030. It also underscores the importance of federal subsidies granted to clean energy businesses and household purchases of electric vehicles through the Bipartisan Infrastructure Law and Inflation Reduction Act. In addition, the NCA also notes that since 2018, the number of mitigation activities at the state level has increased by 83%.
Shading indicates the number of mitigation activities taken by each state, and orange circles indicate cities with emissions-reduction targets (as of April 2023). Credit: The Pennsylvania State University, NOAA NCEI, and CISESS NC.
As in the adaptation chapter, the mitigation chapter of the NCA emphasizes that strategies must be implemented through an equitable lens. The report states, “Although environmental impacts and energy insecurity are not borne proportionately across social groups, it is possible to pursue mitigation options that also redress current and historical injustices.”
While progress is being made to address climate change, the fifth National Climate Assessment outlines that there is much work to be done. Further, the report says that work, whether in adapting to a changing climate or working to mitigate further damage, requires support from the public, as well as policy change within both government and the private sector.