Climate change may exacerbate heavy rainfall, heatwaves, droughts, and wildfires, making them more severe and prolonged worldwide.
1. Heavy Rainfall
For every 1°C increase in average temperature, the atmosphere can hold about 7% more moisture. This can lead to more raindrops and heavier downpours, sometimes occurring in short bursts over small areas. Scientists assess whether extreme weather events can be attributed to climate change by examining both natural and human-induced causes.
In the case of heavy rainfall in Dubai, United Arab Emirates (UAE), and Oman in April 2024, it is challenging to accurately determine the role of climate change. This is because heavy rain is rare in this region, providing scientists with few historical examples for comparison. However, the severity of such events has increased by 10 – 40%, and climate change is considered the most plausible explanation, according to the World Weather Attribution (WWA) organization.
Heavy rain turned Dubai streets into rivers in early April. (Photo: NBC).
In the same month, severe flooding occurred in several areas of East Africa. It is too early to conclude how climate change contributed to that event. However, heavy rainfall in the same region in October and November 2023 was exacerbated by a combination of climate change and a natural weather phenomenon known as the “Indian Ocean Dipole,” according to WWA. In September 2023, northern Libya experienced deadly flooding. The likelihood of heavy rainfall occurring was increased by a factor of 50 due to climate change, and years of political instability hindered preparedness for such events.
Globally, heavy rainfall events are becoming more frequent and intense in most land areas due to human activity, according to the Intergovernmental Panel on Climate Change (IPCC) of the United Nations. This trend is expected to continue as the Earth warms.
2. Heatwaves
Even a small increase in average temperature can make a significant difference in extreme heat events. In early April 2024, temperatures in Mali reached 48.5°C during a heatwave in the Sahel region of Africa, which was associated with a rise in hospitalizations and deaths. Such extreme heat could not have occurred without human-caused climate change.
In the UK, temperatures reached 40°C for the first time in history in July 2022, causing widespread disruption across the country. Heatwaves are also lasting longer in many places, including the UK. This can occur due to heat domes, areas of high pressure where hot air is pushed down and trapped, resulting in soaring temperatures over large areas.
One hypothesis suggests that higher temperatures in the Arctic, which are warming nearly four times faster than the global average, are causing strong winds known as jet streams to slow down, increasing the likelihood of heat domes forming.
3. Drought
Linking climate change to individual drought events can be quite challenging. Water availability depends on many factors beyond temperature and rainfall, including natural weather systems that play a significant role. This was the case with the drought in southern Africa in early 2024. However, heat from climate change can worsen drought conditions by drying out the soil, leading to quicker warming of the overlying air and more intense heat.
During hot weather, the demand for water increases, especially from farmers, putting additional strain on water supplies. In many parts of East Africa, the rainy season has been absent for consecutive years from 2020 to 2022, leading to the worst drought in 40 years and displacing 1.2 million people in Somalia. Climate change is likely making such droughts occur more than 100 times more frequently, according to WWA. Human-caused warming is also the primary driver behind the most severe drought in the Amazon rainforest in half a century, which occurred in the latter half of 2023.
4. Wildfires
Wildfires occur naturally in many parts of the world. It is difficult to determine whether climate change is worsening wildfires, as many other factors, such as land use changes, also contribute. However, climate change creates the necessary weather conditions for fires to spread more widely, according to the IPCC. Prolonged extreme heat draws moisture from the land and vegetation. Dry conditions provide fuel for fires to spread at incredible rates, especially when strong winds are present. Canada experienced its worst wildfire season on record in 2023. Climate change has also doubled the likelihood of wildfire conditions occurring in eastern Canada in May and June 2023.
Rising temperatures may increase the likelihood of lightning strikes in northern forests, triggering fires. According to the United Nations Environment Programme (UNEP), extreme wildfires will become more common and intense globally in the future due to the combined effects of land use changes and climate change, with occurrences projected to increase by 50% by 2100.
