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By Allen Campbell, JD, MBA

On November 14, 2023 The United States Government released the Fifth National Climate Assessment (NCA5), a report on climate change impacts, risks and responses in the United States. It is the most comprehensive federal effort to assess the findings of climate science and communicate the impacts of climate change on people, communities, and ecosystems across the United States. Congress created the interagency U.S. Global Change Research Program in 1990 on an overwhelmingly bipartisan basis. As the NCA5 makes clear, climate impacts affect everyone everywhere. The report reflects extensive, rigorous research, analysis, and known scientific knowledge. Hundreds of authors from across the country – from federal agencies, academic institutions, nonprofits and businesses – provided input to the NCA5. It is a very long report, but well worth reading.

For the first time, the NCA5 includes

  • a chapter on economics, which highlights economic impacts and opportunities associated with climate action, and
  • a chapter on social systems and justice, which discusses how people understand, experience, and respond in different ways to climate change. Not surprisingly, it shows that some communities are disproportionately impacted by climate change.

Key highlights:

1. The United States is making progress on climate change.

One very encouraging finding: Greenhouse gas emissions from the US continue to fall, even as population and GDP have grown. Across the country, climate actions are underway in every region. City- and state-level mitigation and adaptation actions have significantly increased. Zero-carbon and low- carbon energy options are becoming more affordable, transforming the energy system through increased electrification, energy efficiency, and use of clean energy technologies. For example, wind energy costs dropped 70% and solar energy costs dropped 90% over the last decade. In 2020, 80% of new energy-generation capacity came from clean energy. This energy transition will create new economic opportunities, as increased demand for clean energy and low-carbon technologies typically leads to long-term expansion in most states’ energy and decarbonization workforces.

2. Americans are experiencing increasing risks from extreme events.

Total global greenhouse gas emissions from human activities continue to increase, resulting in rapid warming and other impacts. People across the US are experiencing warmer temperatures and longer heatwaves. Many other extremes, including heavy precipitation, droughts, floods, wildfires, and hurricanes, are increasing in frequency and severity. Extreme events cost the United States close to $150 billion each year. In addition, we are experiencing loss of life, health care-related costs, or damages to our natural environment.

3. Climate change exacerbates societal inequities.

Underserved and overburdened communities face disproportionate risks and impacts from climate change, which exacerbate existing social and economic inequities. Some overburdened communities are at higher risk of climate impacts due to ongoing systemic discrimination, exclusion, and under- or disinvestment. These social inequities contribute to persistent disparities in the availability of resources needed to prepare for, respond to, and recover from climate impacts.

4. There are known methods to mitigate climate risks, but the future of climate change cannot be predicted with confidence.

Global warming will depend on current and future emissions. The NCA5 covers most of the relevant considerations. Four to keep an eye on: nature-based solutions, technological advances, evolving business practices and the changing global legal ecosystem. As Yogi Berra famously said, “It’s tough to make predictions, especially about the future.”


Web-based tool:

In a first, the NCA5 also delivers an impressive web-based tool that consolidates state-of-the-art climate science and allows users to explore updated climate projections that can inform local resilience, adaptation, and mitigation efforts in their own state or county. It also for the first time examines how certain communities are impacted disproportionately by climate change.

Key Takeaways:

  • Climate change is a serious, complex problem that needs to be solved.
  • Good solutions will require high-quality data and analysis, sound strategy, abundant funding and effective execution.
  • The NCA5 provides data and conclusions that will inform national policy – and probably also international policy – for at least a few years.