Extreme heatwave days already hitting poorer nations more than rich: the percentage of hot days each year in low-income countries rose from 37 days during the 1961-90 base period to 80 days by 2010. By contrast, rich nations had the percentage of hot days rise much slower from 37 to 55 days

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Extreme heatwave days already hitting poorer nations more than rich: the percentage of hot days each year in low-income countries rose from 37 days during the 1961-90 base period to 80 days by 2010. By contrast, rich nations had the percentage of hot days rise much slower from 37 to 55 days