Planet is entering ‘new climate regime’ with ‘extraordinary’ heat waves intensified by global warming, study says
clock Simultaneous heat waves scorched land areas all over the Northern Hemisphere last summer, killing hundreds and hospitalizing thousands while intensifying destructive and deadly wildfires. A study published this week in the journal Earths Future concludes that this heat wave epidemic would not have occurred without human-induced climate change. The alarming part? There are signs record-setting heat waves are beginning anew this summer signaling, perhaps, that these exceptional and widespread heat spells are now the norm. In the past few days, blistering, abnormal heat has afflicted several parts of the Northern Hemisphere, including major population centers. New Delhi, Indias capital, soared to 118.4 degrees (48 Celsius) Monday, its highest temperature ever recorded in June . Some parts of India have seen the mercury eclipse 122 degrees (50 Celsius) in recent days, not far off the countrys all-time high . It is horrid: India roasts under heat wave with temperatures above 120 degrees On the other side of the hemisphere, the temperature in San Francisco shot up to 100 degrees (37.8 Celsius) Monday, its highest temperatures ever recorded in the months of June, July or August, or this early in the calendar year. San Francisco soars to 100 degrees as record heat wave torches California and the West Coast Heat spread unusually far north, even up into the northern reaches of Scandinavia. Mika Rantanen, a meteorologist at the University of Helsinki, tweeted last Friday that there are no known cases in Finlands climate history when it has been hotter than now so early in the summer. Temperatures above 86 degrees (30 Celsius) penetrated inside the Arctic Circle, he noted . Historical chart. There are no known cases in Finland's climate history when it has been hotter than now so early in the summer. pic.twitter.com/CrJAEKw49D A heat wave in Japan at the end of the May set scores of records , including the countrys highest temperature ever recorded in the month (103.1 degrees, or 39.5 Celsius). The oppressive conditions were blamed for five deaths and nearly 600 hospitalizations . While some scientists hesitate to attribute individual heat spells to climate change, Daniel Swain, a climate scientist at the University of California at Los Angeles, tweeted that his research suggests that weve reached the point where a majority (perhaps a vast majority) of unprecedented extreme heat events globally have a detectable human influence. It was 84 degrees near the Arctic Ocean as carbon dioxide hit its highest level in human history Last summer, exceptional heat affected 22 percent of the populated and agricultural areas of the Northern Hemisphere between the months of May and July, the Earths Future study said. The contiguous United States witnessed its hottest May on record, California endured its hottest July and numerous European cities notched their highest temperatures ever recorded, while cities in Asia, the Middle East and Africa also established new heat milestones. Red hot planet: Last summers punishing and historic heat in 7 maps and charts It remains to be seen whether heat waves this summer become as pervasive and intense as last summer. That said, the Earths Future study concluded weve entered a new climate regime, featuring extraordinary heat waves on a scale and ferocity not seen before. The studys modeling analysis, conducted by researchers in Switzerland and the United Kingdom, found heat events like last summers do not occur in historical simulations and were unprecedented prior to 2010. As the climate warms, the study projects that the area affected by heat waves like last summers will increase 16 percent for every 1.8 degrees (1 Celsius) of warming. Heat waves will likely reach highly dangerous levels for ecosystems and societies over the coming decades, the study said. Heat events like those last summer are predicted to occur two every three years for global warming of 2.7 degrees (1.5 Celsius) and every year for warming of 3.6 degrees (2 Celsius). So far, Earth has warmed by approximately 1.9 degrees (1.05 Celsius) since 1880. The goal of the Paris agreement on climate change is keep the global temperature rise to 3.6 degrees (2 Celsius) or less. Last week, a study in the journal Science Advances found that keeping warming to 2.7 degrees (1.5 Celsius), compared with 5.4 degrees (3 Celsius), could avoid between 110 and 2,720 heat-related deaths annually in 15 different U.S. cities. A strong reduction in fossil fuel emissions is paramount to reduce the risks of unprecedented global-scale heat-wave impacts, the Earths Future study concluded.