Extreme weather

Extreme weather includes unexpected, unusual, severe, or unseasonal weather—weather at the extremes of what has been seen in the past for a particular place. The main types of extreme weather are heat waves, cold waves, droughts, and heavy precipitation or storm events, such as tropical cyclones. These events can cause natural hazards like floods and landslides, and they often bring social costs affecting human health and the economy.

Weather patterns naturally change over time, and these changes can influence extreme weather. Phenomena like the El Niño-Southern Oscillation and the North Atlantic oscillation affect weather worldwide. While no single event can be blamed on one cause, changes in the global climate system can lead to more frequent and stronger extreme weather events.

Climate change may make some extreme weather events, especially heat waves and cold waves, more common and more intense. Scientists use climate models and study rising temperatures to understand how a warming world might change the patterns of extreme weather. This helps us better predict and prepare for such events.

Extreme weather can have serious effects on people and nature. It can lead to loss of lives, damage to buildings and infrastructure, and harm to ecosystems. Human activities, such as poor urban planning, destroying wetlands, or building homes on floodplains, can make the impacts of extreme weather even worse. Understanding extreme weather helps societies protect lives and property better.

Definition

Extreme weather describes unusual weather events that are at the extremes of what has historically been recorded for a given area. According to the IPCC Sixth Assessment Report, an extreme weather event is rare for a particular place and time of year. The World Meteorological Organization defines severe weather as any aspect of weather that poses risks to life, property, or requires help from authorities. Severe weather is a type of extreme weather.

Types

Extreme weather includes unexpected or unusual weather events that are very severe or unseasonal. These can include heavy rain, droughts, very hot or very cold temperatures, and powerful storms.

Heat waves are periods of unusually high temperatures. They can harm people, animals, and plants, and may cause wildfires or damage crops. Cold waves are sudden drops in temperature, which can also be dangerous to living things and can damage water pipes. Heavy rain and storms, including tropical cyclones, can cause flooding and other problems. When rainfall patterns change, some places may get much more rain while others become drier, leading to droughts.

Causes and attribution

Further information: Extreme event attribution

Extreme weather happens for many reasons, and usually more than one cause is involved. Scientists study how changes in our planet’s climate affect the frequency and intensity of extreme weather. They use computer models to predict future weather patterns based on today’s data. These models help us understand how things like rising temperatures might change the weather we experience.

The climate naturally changes over time due to Earth’s tilt, orbit, and water cycle. Events like El Niño can also influence weather in different parts of the world. However, human activities, such as burning fossil fuels, are increasing the chances of extreme weather. Warmer temperatures can lead to more heat waves, heavier rain, and stronger storms. For example, hurricanes are getting stronger, and floods are happening more often. Cities can make these effects worse by covering natural areas with concrete and building in places that are at risk of flooding.

Effects

In recent years, we have seen more record-high temperatures than record-low temperatures across much of the world. Scientists predict that as the Earth warms, extreme weather events like heat waves, heavy rains, and storms will happen more often and become more intense.

Extreme weather can affect many parts of life, including the economy and people's health. It can also cause natural hazards such as floods and landslides. While the number of deaths from natural disasters has decreased over time, extreme temperatures still affect many people each year.