经济学人下载: 加州:危机未平,野火又起(2)

On August 16th a monitoring station in Death Valley measured a temperature of 54.4°C (130°F). If confirmed, that would be the highest reliably recorded anywhere on Earth. It may reflect a broader trend of global warming hitting Californians harder than most places. According to the National Oceanic and Atmospheric Administration, temperatures in many parts of the state, including Santa Clara County, which is being scorched by the largest of the fires, rose by 2°C between 1895 and 2018, roughly twice the global average.
8月16日，死亡谷的一个监测站测量温度为54.4摄氏度（合130华氏度）。如果该检测温度得到证实，这将是地球上最可靠的记录。这可能反映出全球变暖趋势给世界各地带来了严重打击，其中加州人受创尤为严重。根据美国海洋及大气管理局的数据，包括正在遭受最严重的野火灾害的圣克拉拉县在内，加州许多地区的温度，在1895年至2018年期间上升了2摄氏度，大约是全球平均上升气温的两倍。

The state is drier as well as hotter. California has experienced droughts throughout history, but the one between 2011 and 2019 was the longest and driest recorded. According to a study in Nature Geosciences in 2019, that drought killed almost 150m trees, leading to a state of emergency in 2019 intended to help reduce the huge build-up of flammable dead wood. Too late. Drought returned this year, when the state had its driest February on record (matters improved a bit later). A recent study in Environmental Research Letters by Michael Goss of Stanford University and others found that climate change had doubled the number of days of extreme risk for wildfires in the state during autumn.
加州气候干旱且炎热。加州在历史上经历过干旱，但2011年至2019年间的干旱是有史以来历时最长、最干燥的一次。根据《自然地球科学》2019年的一项研究，那场干旱导致近1.5亿树木死亡，也致使加州在2019年进入紧急状态，意图帮助减缓易燃枯木的大量增长。但是太晚了。今年旱灾复发，加州经历了有史以来最干旱的2月（后来情况有所好转）。斯坦福大学的迈克尔·戈斯等人最近在《环境研究快报》上发表的一项研究发现，气候变化使加州秋季发生极端野火灾害的天数增加了一倍。

There is some evidence that climate change is also increasing the danger of lightning strikes, which (rather than burst tyres) lit the inferno this season. Northern California’s fires began after a massive electrical storm passed over the Bay Area in mid-August, producing, said CAL FIRE, 11,000 strikes in three days. According to a study published in 2014 in Science by David Romps of the University of California, Berkeley, climate models suggest the number of lightning strikes across the continental United States could rise by about 12% for every degree of global warming (though another study, in Nature, questions the link with climate change).
有证据表明，气候变化也会增加雷击的危险，闪电（而非爆胎）引发了不息的野火季。八月中旬，一场大雷暴席卷了海湾地区，此后加州北部的野火灾害拉开序幕，加州消防局表示，这场雷暴在三天内发生了1.1万次雷击。根据加州大学伯克利分校的大卫·罗姆斯2014年在《科学》杂志上发表的一项研究，气候模型表明，全球变暖每加剧一级，美洲大陆的雷击次数可能上升约12%（尽管《自然》杂志的另一项研究质疑雷击与气候变化的联系）。