Effects of Global Warming

Rising mean global temperature sets off a chain of physical effects rather than a single uniform change. Melting polar ice caps and glaciers raise sea levels, threatening submergence of low-lying coastal cities worldwide. Weather patterns shift toward more extreme swings — some regions face more frequent or severe flooding, others face longer droughts — because a warmer atmosphere holds and redistributes moisture differently than a stable one. Ecosystems and species ranges shift as organisms track the climatic conditions they are adapted to, which can fragment existing communities and put pressure on species that cannot move or adapt quickly enough; tropical and sub-tropical regions face a particular risk of falling food production as heat and water stress intensify. The chapter's own breakdown of relative greenhouse-gas contribution shows why CO2-focused mitigation …