世界气候归因研究组织近日发布研究表明，人为气候变化使加拿大西北地区和安大略西北部引发大规模野火的条件可能性增加了一倍[1]。研究对比了当前气候与工业革命前的情景，发现安大略省的极端火灾天气在工业前气候下可能一生难遇一次，而在现今气候条件下约每六年就会发生一次[1]。加拿大森林局火灾科学家Jonathan Boucher指出，"在工业前气候下这种情况发生的可能性要小得多，也许一生都遇不到一次。所以气候变化使得这些事件更容易发生"[1]。
加拿大西北地区野火已烧毁超过5000平方英里（12950平方公里）[1]。虽然加拿大野火中约一半由人为引起，但闪电引发的火灾占加拿大烧毁土地面积的90%以上[1]。这一发现与特朗普近期的表态形成对比。特朗普7月21日表示，加拿大"没有妥善管理森林"[1]，将火灾归咎于管理不善。然而科学家指出，根本原因是气候变暖导致的更干旱炎热条件。
过去30年间，加拿大年均被野火烧毁的土地面积增加约50%，美国则增加超过一倍[1]。加拿大的变暖速度比美国快65%[1]，这进一步加剧了野火风险。
A new study by the World Weather Attribution research organization has determined that human-caused climate change doubled the likelihood of the extreme weather conditions that fueled Canada's massive summer wildfires [1]. Researchers compared current conditions to a pre-industrial climate scenario without 2.5°C (1.4°C) of warming, finding that the shift has made such catastrophic fire conditions far more probable [1]. In Ontario's northwestern region, extreme weather that would have been virtually impossible before industrialization—occurring perhaps once in a lifetime—now strikes approximately every six years [1].
The wildfires scorched more than 5,000 square miles (12,950 square kilometers) across Canada's northwest territories [1]. While roughly half of Canadian wildfires are human-caused, lightning-sparked fires account for over 90 percent of the total burned land area [1]. Jonathan Boucher, a fire scientist with the Canadian Forest Service, stated: "In a pre-industrial climate this would have been much less likely to occur, maybe once in a lifespan. So climate change has made those events more likely" [1].
Climate trends underscore the accelerating danger. Over the past three decades, the annual land area burned by wildfires in Canada has increased by approximately 50 percent, while the United States has experienced more than a doubling [1]. Canada is warming 65 percent faster than the United States [1]. Despite these scientific findings, former U.S. President Donald Trump blamed mismanagement on July 21, stating: "They're not managing their forests properly" [1].