Weather patterns will change. For example, there will likely include be a higher frequency of heat waves. Many regions that are currently relatively dry will tend to become even drier.
Increased Heavy Rainfall Events
As the climate warms, atmospheric water vapor content increases, potentially leading to increases in heavy precipitation. Heavy precipitation (defined as the heaviest 15% of daily rainfall) is likely to increase 3-10% for each 1.8°F (1°C) of warming. Changes are likely to be greatest in tropical regions. Increases in heavy precipitation could lead to increased flooding. The science is still quite uncertain regarding where and by how much heavy precipitation events will change.
Protect vital infrastructure from flooding associated with extreme weather. Prevent new development in areas that cannot be adequately protected from flooding.
Global, especially the tropics
More Heat Waves
The frequency and severity of heat waves in Europe and North America are expected to increase. It is estimated that with a 5.4°F (3°C) warming, 9 out of 10 summers will be warmer than all but about 1 of the 20 summers in the last decades of the 20th century. These changes will increase the risk of heat-related illness and death.
Implement early warning systems and emergency response plans for heat waves. Improve building design to reduce heat loads during summer months. Develop urban design that reduces the urban heat island effect by planting trees and increasing green spaces.
Europe and North America
Precipitation will tend to increase in northern regions of the United States. Rainfall in Alaska and other high-latitude areas in the Northern Hemisphere is expected to increase about 5–10% per 1.8°F (1°C) of warming. This increased precipitation could lead to flooding, erosion, and other problems. It is unclear how rainfall amounts will change over large parts of the United States, particularly during the summer.
Establish and implement systems to manage flooding, erosion, and nutrient leaching. Develop flood resistant crops.
Northern United States, Alaska
Rainfall in southwestern North America, the Mediterranean, and southern Africa is estimated to decrease about 5–10% for every 1.8°F (1°C) of warming. This will impact crop growth and drinking water availability. It is unclear how rainfall amounts will change over large parts of the United States, particularly in the summer.
Adopt irrigation practices that save water. Use technologies to harvest water and conserve soil moisture. Use water more conservatively in areas where aquifers are not being replenished.
Mediterranean, Southwestern North America, Southern Africa
The area affected by drought is likely to expand with changes in precipitation and soil moisture brought on by global climate change. Human activities like urbanization, deforestation, and agricultural practices also impact drought.
Reduce water demand by increasing efficiency of use. Manage for water-conserving species and store water to maintain adequate flows during droughts.