How climate change is leading to more extreme weather events

In the past decade, scientists have published hundreds of studies looking at causes of extreme weather around the world. From heatwaves in the Mediterranean to floods in Europe , and wildfires in Australia to hurricanes in the US, there is mounting evidence that human activity is compounding the risk, especially when it comes to heat. Climate change is already having visible effects on the world. The Earth is warming, rainfall patterns are changing, and sea levels are rising. And these changes can increase the risk of heatwaves, floods, droughts, and fires. A recent analysis by the Met Office, the UK’s national weather agency, found a warming planet leads to other extreme changes. Over the past few years, heatwaves have been the “deadliest global weather hazard”, it said. Oceans absorb 90 per cent of the extra heat generated by human influence and, when the water heats up, it expands to take up more space, in turn leading to a rise in sea levels. In future, the Met Office projects that the world will see “warmer and wetter winters, hotter and drier summers and more frequent and intense weather extremes”. Here, The National looks at how climate change is linked to some of the world’s most extreme weather. Around the globe, hot days are getting hotter and more frequent. As cities develop and expand, vegetation is often lost to more roads and buildings. This rapid development and loss of green spaces can lead to higher temperatures by creating 'urban heat islands'. An urban heat island occurs when a city or metropolitan area experiences temperatures that are significantly warmer than its surrounding rural areas, usually due to human activities. Green spaces are considered an appropriate way to reduce the urban heat island effect and provide comfort to residents. In July 2019, western Europe experienced record temperatures. In the UK the mercury rose to 38.7°C — the highest daily maximum temperature on record for the country. A study published in the IOPscience journal looked at whether human activity was to blame for the heat in Europe. “The heatwaves that struck western Europe were rather short-lived, [three to four days], yet very extreme as far as the highest temperatures are concerned,” it said. “Many all-time records were broken in most countries of western Europe, including historical records exceeded by one to two degrees. “Using an unprecedented number of climate model ensembles and statistical extreme value modelling, we demonstrate that these short and intense events would have had extremely small odds in the absence of human-induced climate change, and equivalently frequent events would have been 1.5°C to 3°C colder.” The UN has said water is the primary medium through which we will feel the effects of climate change. As higher temperatures set in and become more extreme and less predictable, conditions are projected to affect “availability and distribution of rainfall, snowmelt, river flows and groundwater, and further deteriorate water quality”. Low income communities will likely be the worst-affected and more floods and severe droughts are predicted. Right now, Madagascar is experiencing one of the worst droughts in its history, with many calling it the climate change famine. After four years without rain, the lack of harvest has devastated farmers and left families hungry. On the other side of the world, in western Europe, 2021 brought some of the most devastating floods to hit the region in decades. In July, heavy rainfall associated with low-pressure system “Bernd” led to severe flooding, particularly in Germany and Belgium. A study published by World Weather Attribution said climate change worsened the floods. “Climate change increased the intensity of the maximum one-day rainfall event in the summer season in this large region by about three to 19 per cent compared to a global climate 1.2°C cooler than today,” the authors of the study said. “These numbers are based on an assessment including observations, regional climate models and very high resolution climate models that directly simulate convection. “In summary, our results highlight that at local scale detection of extreme precipitation trends is hindered by variability, but when considering such events occurring over the larger western Europe region, significant trends attributable to human-induced climate change are evident.” Fires that devastated large parts of Greece this month highlight the need for radical shifts in behaviour to combat climate change. Greek Prime Minister Kyriakos Mitsotakis said the blazes were fuelled by an intense heatwave that struck much of southern Europe and was blamed on global warming. There are several ways climate change can increase the risk of wildfires, drought being one of them. When temperatures increase, it speeds up the rate of evaporation causing plants and land to lose moisture quickly. When vegetation dries out and is exposed to direct, extreme heat – or a small spark – fires can ignite and spread rapidly.