Climate change affects ecosystems through greenhouse-gas forcing, feedback cycles, habitat shifts, coral stress, phenology changes, and evolutionary responses across many environments.
Coverage 2010–2025 · Updated 16 Jul 2026
• Human activities increase atmospheric CO₂, methane, and other greenhouse gases
• Fossil fuels, cement, agriculture, deforestation, and land-use change are major sources
• Positive feedback amplifies warming after an initial climate change
• Examples include ice-albedo loss, permafrost methane, ocean CO₂ release, and wildfire feedback
• Boreal forests can shift from carbon sinks to carbon sources
• Warming, drought, reduced snowfall, browning, insects, and fire increase tipping-point risk
• Melting landfast ice and sea ice alters breeding, feeding, and resting habitat
• Emperor penguins and walruses illustrate species dependent on ice timing and extent
• Ocean warming strengthens stratification and can reduce nutrient upwelling
• Reduced upwelling lowers phytoplankton productivity and food supply
• Species ranges can shift poleward, upslope, or contract as climate zones move
• Montane birds and North American tree species show changing distribution limits
• Warming causes coral bleaching by disrupting coral-zooxanthellae mutualism
• Ocean acidification suppresses calcification, threatening reef biodiversity and collapse
• Carbon sequestration captures and stores atmospheric carbon dioxide
• Afforestation, agroforestry, forest regeneration, and peatland rewetting increase carbon stores
