Heat waves attributable in part to climate change are forecast to kill hundreds of thousands this century. Climate change will also have disastrous effects on water supplies, agriculture and the spread of disease. Rich and poor alike will be affected, but countries that are already struggling to provide food and water for their people will suffer the most.
Climate change increases the spread of disease in a number of ways, most significantly by increasing the range of tropical and sub-tropical pest that carry infection, such as malaria- and dengue-carrying mosquitoes. Roughly 300 million more people will be at risk of malaria with global warming of about 2 to 3 C. Floods will also compromise water quality — spreading cholera and other diseases.
The world’s current shortage of fresh water will greatly worsen because of disappearing glaciers, increasing droughts and salt-water intrusion. The Intergovernmental Panel on Climate Change estimates that three billion or more additional people will be at risk of water shortage due to climate change. The Stockholm Environment Institute estimates that, using only a moderate projection of climate change, 63 per cent of the global population will live in countries of significant water stress by 2025.
Food production in many parts of the world will be damaged by droughts, water shortages, rising sea levels, floods, heat waves and temperature shifts. Mid-continental areas, including vast parts of Asia and the U.S. grain belt, are likely to dry. In areas where dry land agriculture depends solely on rain, such as in sub-Saharan Africa, even a minimal increase in temperature would dramatically decrease food production.
The susceptibility of rice to even a small temperature shift is particularly disturbing. A study by the International Rice Research Institute says rice yields decrease by 10 per cent for every 1 C increase in minimum nighttime temperature. Rice is the staple food for more than half of the world’s population — meaning this one impact of climate change could have profound consequences.