Nico Stehr rightly argues that democracy is crucial in the fight against global warming, attributing the inadequate response of most democracies to an overall lack of public engagement (Nature 525, 449–450; 2015). Our findings at the Environmental Voter Project indicate that a contributory factor could be a lamentably low turnout by environmentalist voters. The Environmental Voter Project is a non-partisan, non-profit organization (www.environmentalvoter. org). We estimate that there could be almost 16 million environmentalists in the United States who rarely or never vote — around 7% of the country’s voting-eligible population. To arrive at this figure, we brought in data analysts who used a data-rich voter file to create a national predictive modelling survey to identify people with a very high likelihood of believing that climate change is both humaninduced and a crucial issue. They then used public voter files to determine the number in this group who failed to vote in national mid-term elections. Until many more environmentalists vote, US politicians at least are unlikely to give environmental issues the attention they so badly need.
Nathaniel Stinnett, Environmental Voter Project, Boston, Massachusetts, USA.