Climate Feedbacks and Greenhouse Gases

Greenhouse gases influence climate through radiative absorption, atmospheric transport, chemical breakdown, and interactions with ecosystems.

The subject includes the continuing warming effect of additional carbon dioxide, changing atmospheric lifetimes of gases such as nitrous oxide, and feedbacks from wildfires, wetlands, and thawing permafrost that can add emissions as the planet warms. These mechanisms matter because model assumptions affect temperature projections, emissions budgets, ozone assessments, and estimates of greenhouse-gas potency. Key questions involve how fully current climate models represent these processes and how physical uncertainty should inform climate risk decisions.