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NCA5 Logo
    • About This Report
    • Guide to the Report
    • Report Credits
    • Companion Podcast
    • Additional Resources
    • About this Report
    • Guide to this Report
    • OVERVIEW
    • Physical Science
    • 2. Climate Trends
    • 3. Earth Systems Processes
    • National Topics
    • 4. Water
    • 5. Energy
    • 6. Land
    • 7. Forests
    • 8. Ecosystems
    • 9. Coasts
    • 10. Oceans
    • 11. Agriculture
    • 12. Built Environment
    • 13. Transportation
    • 14. Air Quality
    • 15. Human Health
    • 16. Indigenous Peoples
    • 17. International
    • 18. Complex Systems
    • 19. Economics
    • 20. Social Systems and Justice
    • Regions
    • 21. Northeast
    • 22. Southeast
    • 23. US Caribbean
    • 24. Midwest
    • 25. Northern Great Plains
    • 26. Southern Great Plains
    • 27. Northwest
    • 28. Southwest
    • 29. Alaska
    • 30. Hawai'i and US-Affiliated Pacific Islands
    • Responses
    • 31. Adaptation
    • 32. Mitigation
    • Focus On
    • F1. Compound Events
    • F2. Western Wildfires
    • F3. COVID-19 and Climate Change
    • F4. Risks to Supply Chains
    • F5. Blue Carbon
    • Appendices
    • A1. Process
    • A2. Information Quality
    • A3. Scenarios and Datasets
    • A4. Indicators
    • A5. Glossary

    • All Figures
    • All Key Messages
    • View All Report Downloads
  • Art × Climate
  • NCA Atlas
  • EN ESPAÑOL
i

Fifth National Climate Assessment
Focus On

To better address critical and timely topics with themes that span the Assessment chapters, NCA5 pioneered a new feature: a set of five “Focus on…” boxes on important cross-cutting issues. High-priority topics were nominated by authors during early development of the report; final topics were approved for inclusion by the Federal Steering Committee. Authors from multiple NCA5 chapters assessed literature, coordinated cross-report discussions, and contributed text and figures to these features.


  • Focus on Compound Events
  • Focus on Western Wildfires
  • Focus on COVID-19 and Climate Change
  • Focus on Risks to Supply Chains
  • Focus on Blue Carbon

Likelihood

Virtually Certain Very Likely Likely As Likely as Not Unlikely Very Unikely Exceptionally Unlikely
99%–100% 90%–100% 66%–100% 33%–66% 0%–33% 0%–10% 0%–1%

Confidence Level

Very High High Medium Low
  • Strong evidence (established theory, multiple sources, well-documented and accepted methods, etc.)
  • High consensus
  • Moderate evidence (several sources, some consistency, methods vary and/or documentation limited, etc.)
  • Medium consensus
  • Suggestive evidence (a few sources, limited consistency, methods emerging, etc.)
  • Competing schools of thought
  • Inconclusive evidence (limited sources, extrapolations, inconsistent findings, poor documentation and/or methods not tested, etc.)
  • Disagreement or lack of opinions among experts

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