The new report from the Intergovernmental Panel on Climate Change sets out the impacts of rising temperatures. Here are some of the key areas where effects will be felt.
Food security: Major crops - wheat, rice and maize - will likely see production hit by temperature increases of 2C or more in tropical and temperate regions, although some areas may see an increase in yields.
Wheat and maize have already seen reduced yields in many regions and overall across the world. Food security could also be affected by changes to fisheries.
Economy and livelihoods: Annual global economic losses are difficult to estimate, but the impacts associated with a 2C temperature rise could be between 0.2-2 per cent of income, and are more likely to be higher rather than lower.
Economic growth is expected to slow as a result of climate change, making it harder to tackle poverty, particularly in developing countries. Food prices are expected to increase.
Human health: Up to 2050, climate change will mostly exacerbate existing health problems, and across the 21st century will lead to increases in ill-health, particularly in poorer countries. Health impacts include more heat wave-related deaths, increased likelihood of under-nutrition due to reduced food production and increased risk of water, food and insect borne diseases.
There could be positive impacts including fewer cold-related deaths, but overall the negative impacts are likely to outweigh the positives.
Security: More people are expected to be displaced over the 21st century, for example by extreme weather events. Climate change could lead to a greater risk of violent conflicts, including civil war, by worsening causes such as poverty.
Impacts such as rising sea levels could also have an effect on the territory of nation states and their critical infrastructure, while changes to sea ice, shared water resources and fish stocks could worsen rivalries between countries.
Water: Dry areas of the world will see a reduction in water resources, with droughts likely to become more frequent. The percentage of the world’s population affected by water scarcity will increase, but so too will numbers affected by major river flooding.
Water quality will be affected, with risks to drinking water quality. Water resources are already being affected by extreme rainfall and melting snow and ice.
Coasts: Sea level rises will increase the risk of submergence, flooding and erosion in coastal and low-lying areas.
Oceans: Fisheries could be hit by shifts in the range and abundance of marine species. Increased acidity in the oceans, as a result of more carbon dioxide emissions, is a serious risk to coral reefs and polar regions.
Wildlife: A large proportion of species will be at an increased risk of extinction, especially as they face a host of threats including climate change, habitat loss, pollution and invasive species.
Habitats could be dramatically altered, and increases in tree death and forest dieback are projected for many regions through the 21st century as a result of drought and rising temperatures.
Press Association