Overview of Fifth US National Climate Assessment 

By Sustainability Coordinator Jacqui Moy 

Colored pencil landscape with mountains in background, trees in middle ground left, a river in middle ground center, rock landscape in middle ground right, and various plants and animals in foreground. Endangered animals and plants are scattered throughout the drawing with two humans in the middle ground.
Award winning artwork from NCA5 depicting endangered species in different ecosystems in the American West. Taelyn B., Endangered West, 2022

The US Global Change Research program recently published the Fifth US National Climate Assessment (NCA5), administered by the National Oceanic and Atmospheric Administration (NOAA). This assessment identifies and analyzes climate and global change, while also suggesting responses to this change on both national and regional levels. It is a holistic assessment that includes not only the physical science of climate change, but also the social and cultural impacts. 

The report is written for decision makers defined as anyone who makes decisions about climate impacts, including you and me! The assessment includes Physical Science, National Topic, Regional, Response chapters, as well as “Focus on…” Features that discuss especially important themes and an Art x Climate Gallery (a new element to the National Climate Assessment!). 

A main takeaway from the assessment is: There is hope but there is more work to do! The US is on the right track with many climate adaptation and mitigation efforts and greenhouse gas emissions have fallen since 2007 (Report page 5). This is largely due to a decrease in coal use and an increase in natural gas and renewables for electricity. These trends can be seen in the figure from the report included below. The figure depicts the fall of emissions caused by electricity generation in yellow. Transportation (in blue) is now the largest contributor of emissions in the US. 

Compound line chart of US greenhouse gas emissions by sector with 2030 and 2050 emission goals where emissions have fallen since peaking in 2007, though are significantly higher than goals.
US greenhouse gas emissions by sector with 2030 and 2050 goals added. Emissions from electricity generation have decreased along with overall emissions, though emissions are still significantly higher than goals. 

While these trends are hopeful, NCA5 suggests there still much more we need to do — and fast. The US is currently reducing emissions an average of 1% per year, and needs to be reducing by more than 6% per year to meet emission reduction targets (15). 

The US is also warming faster than the global average (40), which is continuing to have significant environmental and social impacts. In the Northeast specifically, the top three climate impacts of significant concern include (21): 

  1. Extreme weather events that damage critical infrastructure
  2. Warming temperatures that shift distributions of coastal and marine species and habitats 
  3. Extreme heat and flooding that disproportionately impact overburdened communities. 

To address these impacts at a sufficient pace, the assessment emphasizes that it will be important to accelerate current adaptation and mitigation efforts in addition to developing and implementing new ones (10). These efforts will not only have environmental and social impacts, but will also help to avoid economic harm associated with increased warming (32). NCA5 also projects that new jobs created for climate change mitigation will outweigh projected job losses in the fossil fuel industry (34).

Reaching net zero emissions is one of the largest challenges we face. Achieving net zero will require  dramatically expanding the renewable energy industry, implementing carbon capture and storage strategies, and implementing transformative adaptation that spurs fundamental changes in our current efforts while ensuring that equity and justice are prioritized. 

NCA5 notes the importance of understanding and addressing inequities in climate impacts. For example, Indigenous Peoples are disproportionately harmed by climate change, as their life and spiritual health are tightly intertwined with nature (30). Indigenous Knowledge and other cultural heritages have also, and will continue to be, key to both climate and cultural resiliency (24). Overall, NCA5 emphasizes the importance of just transition, defined as “…the process of responding to climate change with transformative actions that address the root causes of climate vulnerability while ensuring equitable access to jobs; affordable, low-carbon energy; environmental benefits such as reduced air pollution; and quality of life for all” (46). 

The US not only has a responsibility to address inequities within the country, but also on a global scale. The assessment recognizes that the US has contributed the highest cumulative CO2 emissions from fossil fuels and industry since 1850 than any other country(37). 

All in all, the Fifth National Climate Assessment emphasizes the progress that the United States has made in climate efforts, especially in regards to greenhouse gas emissions reduction.  Simultaneously, it underlines the importance of aggressive steps forward in climate mitigation and adaptation in order to meet targets and commitments, all while ensuring a just transition forward.  Resources to learn more about the findings of the assessment are linked below, including the NCA5 Overview and Northeast Regional Chapter. To further explore the change happening in the US, you can use the NCA5 interactive atlas explorer! And don’t forget to check out the amazing artwork from the Art x Climate gallery! 

(Included page numbers refer to Fifth National Climate Assessment Overview PDF). 

Resources 

Jacqui Moy

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