Sixty-eight percent of Americans believe human activity is causing global warming and 45 percent report “worrying a great deal” about it. Just two years ago, 55 percent believed humans were causing it and only 32 percent worried a great deal.
The survey, conducted by Gallup, has tracked Americans’ perceptions of global warming every March. The previous high of people saying they worry about global warming was 41 percent, recorded in 2007. The low point was 25 percent, recorded as recently as 2011.