Climate change caused by greenhouse gas emissions made heatwaves at least 150 times more likely to occur.
The people of Canada and America are directly responsible for the trouble they are going through in the form of rising mercury. Indeed, last week’s record-breaking heatwaves in parts of the US and Canada would have been impossible without the effects of human-caused climate change, according to a rapid attribution analysis by an international team of leading climate scientists. Scientists found that climate change caused by greenhouse gas emissions made heatwaves at least 150 times more likely to occur. The Pacific Northwest regions of the US and Canada saw temperatures that broke records by several degrees, including a new all-time Canadian temperature record of 49.6ºC (121.3ºF) in the village of Lytton – up from the previous national record of 45ºC (113ºF). Quite a lot. Shortly after setting the record, Litton was largely destroyed in a wildfire. Every heatwave that occurs today becomes more likely and more intense than climate change. To gauge the impact of climate change on these higher temperatures, scientists, using peer-reviewed methods, compared the climate to what it is today after about 1.2 °C (2.2ºF) of global warming from the late 1800s. Analyzed observations and computer simulations to do with past climates. The extreme temperatures experienced were far outside the range of previously observed temperatures, making it difficult to measure how rare this event is in the current climate and how rare it would have been without human-caused climate change – but the researchers concluded that it It would have been “nearly impossible” without human influence. The researchers found two alternative explanations for how climate change made the extraordinary heat more likely. One possibility is that, while climate change has increased the likelihood of such extreme heatwaves occurring, it is also a very unusual phenomenon in the current climate. Pre-existing drought and conditions of abnormal atmospheric circulation, known as ‘heat domes’, together with climate change produce very high temperatures. In this explanation, the maximum temperature would have been about 2 °C (3.6 °F) lower without the effects of climate change. Unless overall greenhouse gas emissions are halted, global temperatures will continue to rise and such events will continue to occur. For example, even if global temperature rise is limited to 2 °C (3.6 °F), which could happen by 2050, scientists found that such heatwaves occur once every 5 to 10 years. An alternative possible explanation is that the climate system has crossed a non-linear boundary, where a small amount of overall global warming is now causing a much faster increase in temperature than has been observed so far. is the probability of being discovered in future studies. This would mean that a record-breaking heatwave like last week’s event is already more likely than climate models have predicted. This raises questions about how well current science can predict the behavior of heatwaves under climate change. The event provides a strong warning that extreme temperatures, outside the currently expected temperature range, may occur at latitudes as high as 50°N, a range that includes all the contiguous US, parts of France, Germany, China and Japan. Scientists warn that adaptation plans must be designed for temperatures much higher than the limits previously observed in recent days. The study was conducted by 27 researchers as part of the World Weather Attribution Group, which included scientists from universities and meteorological agencies in Canada, the US, Germany, the Netherlands, Switzerland, France and the UK. The opinion of some experts in this regard is as follows. “What we’re seeing is unprecedented. Four or five degrees Celsius (seven to nine degrees Fahrenheit) shouldn’t be a record break. It’s such an extraordinary event that we can’t rule out the possibility that the extreme heat we are seeing today We only expect to experience much higher levels of global warming than we are experiencing.” – Frederick Otto, Institute for Environmental Change, University of Oxford “While we are expecting heatwaves to become more frequent and intense, it was unexpected to see such levels of heat in the region. It raises serious questions about whether we really understand how climate change is causing heatwaves to become more frequent.” making it hotter and more lethal.” – Geert Jan van Oldenborg, Royal Netherlands Meteorological Institute “Climate change is making these extremely rare events more frequent. We are stepping into uncharted territory. The temperatures experienced in Canada last week may have broken Las Vegas or Spain’s records. If we do not manage to curb emissions and stop global warming, the temperature will reach much higher records.” – Sonia Seneviratne, Institute of Atmospheric and Climate Sciences, ETH Zurich “Heatwaves top the global charts of deadliest disasters in both 2019 and 2020. Here we have another terrifying example — sadly they are no longer shocking but part of a very worrying global trend Many of these deaths could be prevented by adapting to the hotter heatwaves we face in the region and around the world.” – Martin van Aalst, Red Cross Red Crescent Climate Center and University of Twente “In the United States, heat-related mortality is the number one killer of weather-related deaths, but nearly all of those deaths are preventable. By prioritizing modifications to our built environment, including heat action plans, heatwave early warning and response systems, so that While a warming future does not have to be fatal, increasing preparedness for summer emergencies can reduce current and future heat-related morbidity and mortality.” – Christie L. EB, Center for Health and the Global Environment, University of Washington “This event should be a major warning. We currently do not understand well the mechanisms that lead to such exceptionally high temperatures. We have probably passed a threshold in the climate system where there is a small amount of additional global warming to extreme temperatures.” causes a rapid increase in the world” – Dim Koumou, Institute for Environmental Studies (VU Amsterdam), Royal Netherlands Meteorological Institute (KNMI) “It is amazing to see what we have achieved in just one week, with the 27 scientists and local specialist research institutions and meteorological agencies involved in this rapid attribution. Combining knowledge and model data from around the world into comprehensive study results. Increases trust.” – Sjökje Philipp and Sarah Q, Head of Studies, Royal Netherlands Meteorological Institute (KNMI)