Explained: What's Causing Floods, Heatwave Across The Globe

Extreme weather conditions such as heatwave, heavy rain, flood, and forest fires are being witnessed in different regions of the world. Countries including the US, Spain, Italy, and China are grappling with extreme heat, wildfires triggered evacuation in Greece, while floods killed at least 40 people in South Korea. Scientists attribute these weather conditions to climate change as the planet continues to warm up due to greenhouse gases.  

The World Meteorological Organization (WMO) warned this week that the heatwaves that have gripped the northern hemisphere are not over. According to WMO senior heat advisor John Nairn, extreme temperatures are likely to grow in frequency, duration, and intensity. He said the conditions “are not your normal weather systems of the past” and are the “consequence of climate change”.  

According to the United States Environmental Protection Agency (US EPA), even small changes in the average temperature of the planet can result in significant and dangerous shifts in climate and weather. 

The current heatwave conditions in Europe could be due to several factors, including climate change, according to Dr Melissa Lazenby, Lecturer in Climate Change, University of Sussex. She told Science Media Centre, “The current European Heatwave is being driven by stable atmospheric conditions from a stationary high pressures feature. This heatwave is likely driven by a combination of climate change, El Niño and a stationary high-pressure system also known as an anticyclone”.

Climate change is also believed to be behind the devastating drought that has affected millions of people in the Horn of Africa. According to a study by the World Weather Attribution, low rainfall events that led to the drought have become twice as likely due to human-induced climate change. 

Heavy or excessive rain can also be attributed to climate change. As per the US EPA, rising ocean temperatures lead to more water evaporating into the air. When the atmosphere becomes too moist, it can produce more intense precipitation including snow storms, which increases the risk of flood.