• Ecosystem processes, such as those that control growth and decomposition, have been affected by climate change.
• Large-scale shifts have occurred in the ranges of species and the timing of the seasons and animal migration, and are very likely to continue.
• Fires, insect pests, disease pathogens, and invasive weed species have increased, and these trends are likely to continue.
• Deserts and drylands are likely to become hotter and drier, feeding a self-reinforcing cycle of invasive plants, fire, and erosion.
• Coastal and near-shore ecosystems are already under multiple stresses. Climate change and ocean acidification will exacerbate these stresses.
• Arctic sea ice ecosystems are already being adversely affected by the loss of summer sea ice and further changes are expected.
• The habitats of some mountain species and coldwater fish, such as salmon and trout, are very likely to contract in response to warming.
• Some of the benefits ecosystems provide to society will be threatened by climate change, while others will be enhanced.