"Observational evidence from all continents and most oceans shows that many natural systems are being affected by regional climate changes, particularly temperature increases."
–Intergovernmental Panel on Climate Change (IPCC), 2007
Explore the signs of global warming on this map or Google Earth. The evidence of climate change includes heat waves, sea-level rise, flooding, melting glaciers, earlier spring arrival, coral reef bleaching, and the spread of disease.
The greatest concentration of global warming indicators on the map is in North America and Europe because that is where most scientific investigation has been done to date. As scientists focus increasingly on fingerprints of global warming in other regions—from Russia to Antarctica and Oceania to South America—the evidence they find will be added to the map.
Scientists project that unless emissions of heat-trapping gases are brought undercontrol, the impacts of climate change are likely to increase.
Public health impacts include injuries and deaths from heat waves; more intense storms, floods, and wildfires; more severe and frequent bad-air days; and changes in disease pathways and allergen potency. Discover how global warming impacts our health.
Climate change threatens crops, livestock, and fisheries owing to heat-induced declines in productivity, changes in rainfall timing and intensity, and shifts in the abundance and types of fish and pests. Learn about global warming effects on food.
A changing climate poses risks to the quality and supply of water for drinking, irrigation, shipping, and recreation. For example, rising seas can intrude into coastal groundwater used for drinking. Read about global warming effects on our water supply.
Climate impacts cost time and money by damaging critical infrastructure, disrupting economic activity, escalating medical expenses, losing work days, and requiring adaptations such as moving people out of harm's way. See how global warming affects the economy.
The atmosphere in a warming world holds more water vapor, creating a trend toward more intense precipitation events. Torrential rainstorms and severe blizzards can lead to flooding. Read more about global warming effects on rain and snow.
Higher temperatures accelerate the transfer of water from land surfaces and plants to the atmosphere. This can result in extremely dry conditions in areas with less rain. Read how global warming contributes to droughts.
This category encompasses ice that lasts longer than a year on land, including mountain glaciers, ice caps, ice sheets, and permafrost—most of which are shrinking because of global warming. Discover how land ice is threatened by global warming.
The release of water and ice from glaciers, ice sheets, and ice caps directly into the ocean raises sea level. Sea level also rises as the warming ocean expands. Read more about global warming effects on sea level.
Melting sea ice does not raise sea level, but it does create a cascade of consequences for regional temperatures, reflectivity of ocean surfaces, and creatures that depend on ice. Read about global warming effects on sea ice.
Climate-related changes to ocean chemistry include higher or lower salinity, shifting patterns of nutrients and increasing acidity owing to excess carbon dioxide. Find out how global warming affects ocean chemistry.
Lakes and rivers
Climate change is already adversely affecting the habitats of some animals, fish, and plants that live in freshwater lakes and rivers, while creating new habitats for other species. See how lakes and rivers are impacted by global warming.
Changes in the habitats and life-cycle events of plants and animals that live on land—such as the timing of bud burst, reproduction, and bird migration—are already under way. Find out how global warming affects plants and animals.
Marine plants and animals are already responding to climate-induced changes in ocean chemistry, habitats, and life-cycle events, such as the abundance of phytoplantkton and the growth of young fish. Learn about global warming effects on salt water species.
Rising air temperatures bring heat waves, spread disease, shift plant and animal habitat and cause extreme weather events, from drought to blizzards. Learn about the wide-ranging effects of warmer air temperatures.
Warmer oceans put coastal communities at risk, increase infrastructure costs, endanger polar creatures, threaten coral reefs and fisheries, and accelerate the overall warming trend. Learn about the impacts of rising ocean temperatures.
Warmer lakes, rivers and streams threaten aquatic species, by disrupting reproductive cycles, displacing cold-water species and creating dead zones in deep lakes. Learn about global warming effects on freshwater species.
Thawing permafrost alters local ecosystems, destabilizes infrastructure and releases heat-trapping gases into the atmosphere, which spurs more climate change. Read how increasing ground temperatures worsen global warming.