Climate change is transforming the character of the West's hottest periods — making them more frequent, more persistent and more lethal. For almost all of human history, heat waves have been driven by natural variability — or the tendency of weather patterns to veer occasionally from their typical patterns. Now, however, the accumulation of greenhouse gases due to the burning of fossil fuels is increasing the likelihood and severity of such extreme heat events.
'If we look globally, the number of days with heatwaves has nearly doubled since the 1980s. During that time, heat waves have also increased in duration.' Extreme heat is one of the deadliest effects of climate change. Each year, extreme heat kills more Americans than any other climate-fueled hazard, including hurricanes, floods and wildfires, but it gets far less attention because it kills so quietly.