Climate change is making heavy rainfall, heat waves, droughts, and wildfires more severe and longer-lasting around the world.
1. Heavy Rainfall
For every 1 degree Celsius increase in average temperature, the atmosphere can hold about 7% more water vapor. This can lead to more rain and heavier downpours, sometimes over short periods and small areas. Scientists assess whether an extreme weather event can be attributed to climate change by looking at natural and human-caused influences.
In the case of the extreme rainfall in Dubai, UAE, and Oman in April 2024, it is difficult to say how much of a role climate change played. This is because intense rainfall is rare in the region, so scientists have few historical examples to compare it to. However, the severity of such events has increased by 10-40%, and climate change is a plausible explanation, according to the World Weather Attribution (WWA) initiative.
Floods Devastated Eastern Africa in April 2024
Deadly floods devastated parts of Eastern Africa that same month. It is too early to say how much climate change contributed to this event. But heavy rainfall in the same region in October and November 2023 was made worse by a combination of climate change and a natural climate pattern called the "Indian Ocean Dipole," according to WWA. In September 2023, northern Libya experienced deadly flooding. The heavy rainfall was 50 times more likely to occur because of climate change, and years of political instability had hindered efforts to prepare for such an event.
Globally, extreme rainfall events have become more frequent and intense in most land regions since the 1950s, due to human activities, according to the UN's Intergovernmental Panel on Climate Change (IPCC). This pattern is projected to continue as the planet warms.
2. Heat Waves
Even small increases in average temperatures can make a big difference in the severity of heat waves. In early April 2024, temperatures in Mali reached 48.5 degrees Celsius (119 degrees Fahrenheit) during a heat wave in Africa's Sahel region, which was linked to increased hospitalizations and deaths. This heat wave would have been impossible without human-caused climate change.
UK Saw Its First 40°C Temperature in July 2022
In the United Kingdom, temperatures topped 40 degrees Celsius (104 degrees Fahrenheit) for the first time on record in July 2022, causing widespread disruption across the country. Heat waves are also lasting longer in many places, including the UK. This may be due to a slowdown in the jet stream, the powerful winds that circle the globe, which is thought to be caused by warmer temperatures in the Arctic.
3. Droughts
It can be difficult to link climate change to individual drought events. Water availability depends on many factors besides temperature and rainfall, with natural climate variability also playing a role. That was the case with the drought in southern Africa in early 2024. But heat caused by climate change can exacerbate droughts by drying out soils, which causes the air above them to warm even faster, leading to even more intense heat.
During hot weather, demand for water increases, especially from farmers, putting a strain on water supplies. In parts of Eastern Africa, the rainy season failed repeatedly from 2020 to 2022 as the region experienced its worst drought in 40 years, displacing 1.2 million people in Somalia alone. Climate change made this type of drought at least 100 times more likely to occur, according to WWA. Human-caused warming was also a major factor behind the Amazon rainforest's worst drought 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 hard to say whether climate change makes wildfires worse because so many other factors contribute, such as land-use changes. But climate change is creating the weather conditions necessary for fires to spread more easily, according to the IPCC. Prolonged extreme heat draws moisture out of the ground and vegetation. Dry conditions provide fuel for fires to spread at incredible speed, especially when combined with strong winds. Canada experienced its worst wildfire season on record in 2023. Climate change also doubled the odds of the extreme fire conditions that occurred across eastern Canada in May and June 2023.
Rising temperatures could also increase lightning strikes in northern forests, which can spark fires. According to the UN Environment Programme (UNEP), extreme fires are projected to become more frequent and intense globally in the future due to the combined effects of land-use changes and climate change, with a 50% increase by 2100.