“I think on the one hand we overestimate climate change because it is now very common that every time an extreme event happens, there is a big assumption that climate change plays a big role, which does not always happen,” said Friederike Otto. Professor of Climate Change and Environment at the Grantham Institute at Imperial College London, who was one of the lead authors of the research. “But on the other hand, we really underestimate those events where climate change plays a role in cost, especially the non-economic cost of extreme weather for our societies.” In the study, published in the journal IOP Publishing, Otto’s team used “performance science” to look at available international data, literature and climate models – as well as the latest Intergovernmental Panel on Climate Change reports – and to calculate how man is causing climate change. affect the effects of five types of extreme weather events: heat waves, heavy rainfall, drought, fires and tropical cyclones. They say that in the case of heat waves, the role of climate change is clear and that average and extreme heat levels on every continent around the world are rising especially due to man-made climate change. A heatwave with a 1 in 50 chance of occurring in the pre-industrial era is now almost five times more likely to occur and will be 1.2C higher, according to an IPCC report. In the last 20 years, there have been 157,000 deaths from 34 heat waves, according to data from the EMDAT disaster database. However, the impact of human-induced climate change on heat waves and the effects are still greatly underestimated. “One big reason we underestimate heatwaves so dramatically is because no one falls dead on the street during a heatwave, or at least very few people do,” Otto said. Most people died from pre-existing conditions that suddenly became acute, Otto said, and this was often not seen in the data. The fires were also one of the major climate effects that were not discussed enough, Otto said. For other events, such as droughts, floods and tropical cyclones, there is a more diverse relationship with climate change. For example, there are some areas of the world where droughts are exacerbated by man-made climate change, such as South Africa, Otto notes, while in other droughts the climate change signal is either non-existent or very small. “By focusing too much on climate change, it really takes responsibility, but also the body, to deal with these local disasters, such as high poverty rates, poor infrastructure, investment, the missing health care system; all these aspects of it. exposure and vulnerability that make any drought a disaster, “Otto said. “It will not disappear even if we stop burning fossil fuels today. I think this is why overestimating climate change – by blaming it all basically on climate change – is not very helpful in tackling it. [with] and to improve resilience to these threats. “ Much of the problem in understanding exactly the extent to which climate change is responsible for the impact of extreme weather events, Otto said, lies in the lack of reliable data around the world. Subscribe to the First Edition, our free daily newsletter – every morning at 7am There is not enough information coming from lower and middle income countries, although these are the places most likely to be at risk of human-induced climate change. Substantial scientific progress has already been made in recent years in attributing extreme events and their effects on anthropogenic climate change, said Francis Moore, a professor of environmental economics at the University of California, Davis, who did not participate in the study. “But an important caveat is that the effects of climate change are not limited to extremes,” Moore said. Changes in the “average conditions” can also have major consequences for mortality, agriculture, worker productivity and safety. “The overall consequences of these changing, ‘non-extreme’ conditions may well be a large fraction of the overall impact of climate change.” Otto called for a broader definition of what is considered a “risk” in modeling climate change, rather than simply focusing on the risks and consequences. Other factors, such as the impact of extreme weather on people, labor productivity, infrastructure, farming systems and property, need to be considered, he said. “We started with ‘nobody ever talked about climate change,’ and now we’re moving on to ‘blaming a lot of things on climate change,’” Otto said. “[This is] a call to realize that the reality is somewhat messy, in the middle, and that we need to better disentangle these factors in order to prioritize adaptation and resilience building to really tackle climate change properly. “
