The Impact of Climate Change on Extreme Weather Events

Studies examining whether climate change increases the odds of specific extreme events like heat waves, floods and droughts has rapidly grown over time; this field of inquiry is known as “attribution science”.

Science makes it clear: human-caused climate change makes extreme events more likely and severe. On this page are summaries of recent findings on this subject.

Frequency

Climate attribution science involves attempting to establish whether human-caused warming would have had any bearing on the likelihood or severity of an extreme event, by comparing observations or climate model simulations of current events with idealised models that eliminate their impact.

Researchers have conducted numerous attribution studies of extreme events such as heatwaves, heavy rainfall/flooding events, drought, etc. A recent study concluded that 93% of the 152 heatwaves studied were made more likely or severe by human-caused climate change while only 56% of rainfall/flood events and 81 drought events studied had their likelihood/severity increased because of climate change.

Extreme rainfall events could present more inconclusive results due to being more complex, with natural variability still playing an influencer role. Other studies may not have been able to detect a signal due to limitations in data or model complexity.

Intensity

Studies of human influence on individual extreme weather events can assess its effect in terms of increasing or decreasing frequency or intensity of these weather phenomena. As shown on the map below, red indicates events made more likely by climate change; green represent those made less likely; while grey indicates those where there has been no discernible influence or it remains inconclusive.

Warmer temperatures also increase storm intensity and rainfall amounts during individual events – for instance, as sea water temperatures warm, tropical storms become more powerful (see image below). A decrease in rainfall is one of the more serious consequences of climate change; its lack increases drought risks that can cause wildfires, food shortages and human conflict; this has particularly adverse impacts on rural communities with lower income households as a whole – thus justifying taking action now to support climate justice.

Impact

Extreme weather events pose a real danger to humanity, posing sickness and death risks while disrupting essential services like water, telecom, transportation and energy networks. They are predicted to become increasingly common as our planet warms.

Scientists are getting better and faster at crunching numbers to evaluate how climate change influences extreme weather events, known as event attribution. Studies of 152 heat waves reveal that 93% of them were caused by climate change; similarly, studies on 126 rainfall- and flood events and 81 droughts found human activity has increased their likelihood or severity as temperatures rise causing lakes and rivers to evaporate, leading to drought conditions that make survival harder for wildlife and humans alike.

Adaptation

Climate change not only increases the odds of extreme weather events but can also magnify their severity, which can have devastating repercussions for people and ecosystems alike. A prolonged drought, for instance, can reduce agricultural production resulting in food shortages while heavy rain from hurricanes or typhoons can bring flooding with devastating results.

Short-term adaptation efforts must be accelerated. This is especially relevant for vulnerable groups such as low-income communities, the elderly and individuals living with preexisting conditions.

Carbon Brief has conducted extensive research on heatwaves, floods, wildfires and droughts and their attribution studies published to date. As per these attribution studies’ conclusions, 71% of extreme weather events studied were either made more likely or severe due to human-caused climate change.

High confidence exists that extreme heat and precipitation events will increase across most continental regions as global average temperatures increase further, due to warmer air’s ability to hold more moisture vapor than its colder counterpart. Therefore, heavy rainfall events and heat waves will become more prevalent over time.