How Climate Change is Supercharging our Weather

2023 was the hottest year on record globally, by a long way. People and countries all over the world are being affected by more frequent weather extremes. So how do these weather events happen, and how is climate change contributing to their increased intensity?

Extreme rain

In a warmer world, more heat from the sun causes greater evaporation, which in turn leads to heavier rainfall. Warmer air also holds more moisture. In fact, for every 1-degree Celsius rise in average temperature, about 7 percent more moisture is held in the atmosphere. More, bigger and heavier clouds form and, eventually, the water they hold condenses and falls as intense or even torrential rain.

This can occur in a short space of time and over relatively small areas, leading to devastating flash floods. The UAE, Kenya and Brazil were all inundated with rainfall in early 2024, causing widespread flooding and states of emergency. Record rainfall in Dubai and Oman was made 10-40 percent heavier by climate change, according to scientists at World Weather Attribution (WMA), a group that determines whether extreme global weather events can be directly linked to human-induced climate change.

This weather doesn’t only impact the present, it is shaping the futures of our cities and towns as governments respond. Dubai’s record-breaking flooding prompted the city to announce an $8 billion investment in a comprehensive stormwater runoff system. The massive project, set to be completed by 2027, aims to increase Dubai's resilience against the challenges of a changing climate. Dubai’s runoff system is one example of the shift in mindset from reactive to proactive. Instead of waiting to rebuild after individual catastrophes, leaders are investing more heavily in building weather-proof cities.

Hotter heatwaves

Even a small increase to average temperatures makes a big difference to heat extremes, with less frequent and less intense cold weather but hotter, longer heatwaves.

This is happening due to human activity, which has increased exponentially since the first industrial revolution. Greenhouse gas (GHG) emissions trap heat within the Earth’s atmosphere, leading to a rise in the average global temperature.

In some cases, heat domes can form. High pressure acts as a lid, keeping rising warm air down and compressing it, so it gets hotter. A rapidly warming arctic causing a slowdown in strong winds known as the jet stream could be to blame. Without these winds, there is a higher likelihood that high pressure areas will sit still and create conditions ripe for a heat dome to occur.

In April and May 2024, large parts of Asia, from India to the Philippines, were gripped by a record-setting heatwave. Similar conditions, which were attributed to climate change, were seen in the same part of the world in 2023.

Severe storms

Hurricanes and typhoons are tropical cyclones, low pressure systems with circulating winds rotating around a central calm area called “the eye,” that develop in different parts of the world. They are fueled by warm ocean temperatures and draw energy from the evaporation of seawater. As the climate warms, ocean temperatures are rising and shattering records. This means more moisture can be drawn into powering these storms, increasing their intensity.

While it seems there may be an overall decrease in the number of these storms, tropical cyclones are becoming more intense, more frequently, especially over the Atlantic ocean. In the US, the most damaging hurricanes are three times more frequent than a century ago. The 2023 Atlantic hurricane season was the fourth most active on record.

Devastating drought

Droughts are prolonged periods of dry weather caused by abnormally low rainfall combined with high temperatures. Climate change is making severe droughts 100 times more likely in some areas by altering the natural weather systems. This is what happened to create the drought in west Africa and the Sahel during the early months of 2024. A similarly devastating drought in the Amazon rainforest during 2023 has also been attributed to human-induced climate change.

Droughts create enormous stress on the water supply, especially for farmers, and lead to water scarcity, crop failures and livestock losses. Among the knock-on effects are mass migration as people search for water, and even violent conflicts over dwindling resources. Almost 1.2 million people in Somalia alone were displaced due to the worst drought in 40 years, caused by five failed rainy seasons in a row.

Raging wildfires

Extreme heat leads to land and vegetation so dry it becomes a tinderbox. One spark, from lightning for example, can set it alight, and wind can rapidly spread it.

Bush or brush fires happen naturally in many parts of the world and are integral to many ecosystems. However, human activity and climate change have disturbed land use dynamics, creating conditions that enable them to spread farther and faster.

This was the case for the wildfires in eastern Canada in 2023, where climate change doubled the likelihood of the necessary conditions to fuel “extreme fire weather.” The catastrophic scale and impact of Australia's 2019-2020 wildfires would be seen in the 19 million hectares that burned and nearly 3 billion animals affected.

The UN Environment Programme (UNEP) has warned that the number of wildfires could rise by 50 percent by 2100, making them more numerous and more intense due to climate change.

A wake-up call

Extreme weather events hit the most vulnerable the hardest. These are the nations and people least responsible for the climate crisis that engulfs us, but who are forced to bear the brunt of it in the tragedy and displacement that are all too familiar in our newsfeeds.

But as weather events become more frequent and more severe, the Global North is increasingly reminded that nobody is spared when temperatures climb. And research has shown that extreme weather events have enduring consequences.

Extreme rainfall bogs down the economy, with the service and manufacturing sectors particularly hard hit in high-income nations. Heat waves harm productivity as employees suffer under sweltering days, students struggle with learning, and nations – literally. The European Environment Agency estimates the heat waves in 32 European countries between 1980 and 2000 may have cost up to 71 billion euros , and research estimates that the economies of US states fell average 0.15 to 0.25 percentage points for every one degree Fahrenheit, or a half a degree Celsius that a state’s average summer temperature exceeded normal ranges.

Is it the grim wake-up call needed to spur action? That remains to be seen. But as insurance premiums surge, hospital admissions rise, and livelihoods are put in jeopardy, the pressure mounts on governments to take action. COP28 and its landmark agreement to transition away from fossil fuels indicates that we’re heading in the right direction, but the momentum must be kept up, for the sake of people and the planet.