Climate change is already transforming natural and human systems on every continent and in every ocean. Rising temperatures, changing rainfall patterns and more frequent extremes are disrupting ecosystems, water resources, agriculture, health and infrastructure.

Ecosystems are shifting as species move toward cooler regions or higher elevations. Many plants and animals cannot adapt or migrate quickly enough, increasing extinction risk, particularly for coral reefs, mountain species and Arctic ecosystems. Ocean warming and acidification are bleaching corals, altering food webs and reducing fisheries productivity.

Water resources are becoming more variable. Many regions face increased drought, while others experience more intense rainfall and flooding. Melting glaciers and snowpack initially raise river flows, then lead to long term declines, threatening water supplies for hundreds of millions of people who depend on mountain runoff.

Food systems are under pressure from heat stress, shifting growing seasons and more frequent extremes such as droughts and heatwaves. Crop yields for staples like wheat and maize are already being affected in some regions, particularly in the tropics, with consequences for food security and prices.

Human health is impacted through heat related illness and death, expanding ranges of disease carrying insects, worsening air quality and malnutrition linked to crop failures. Vulnerable populations, especially in low income countries and coastal zones, face the greatest risks.

Coasts and cities confront sea level rise, stronger storms and coastal erosion that damage infrastructure and displace people. Economic losses from climate related disasters are increasing. Without rapid and deep emission reductions combined with adaptation, climate impacts are projected to intensify, become more widespread and increasingly irreversible on human time scales.