The percentage of Americans saying there is solid evidence of global warming has steadily increased over the past few years. Currently, 67% say there is solid evidence that the earth’s average temperature has been getting warmer over the past few decades, up four points since last year and 10 points since 2009.
Similarly, an increasing proportion say that the rise in the earth’s temperature has mostly been caused by human activity. Currently, 42% say the warming is mostly caused by human activity, such as burning fossil fuels, while 19% say it is mostly caused by natural patterns in the earth’s environment. Last year, 38% mostly attributed global warming to human activity and in 2010 34% did so.