Americans agree climate change is real. But made by humans? Not so much.

A large majority of Americans now say there is strong evidence for global warming, according to the 2015 National Survey on Energy and the Environment (NSEE): 70 percent, just two points short of the record-setting number in 2008.

But is this the beginning of the end for climate-change denial? The start of sweeping environmental protection reforms? Support for upcoming global climate talks in Paris? 

Not so fast.

Like most of their senators, US voters are convinced that something’s happening to the Earth, but can’t agree who, or what, is to blame.

It is nearly 27 years now since a NASA scientist testified before the US Senate that the agency was 99 percent certain that rising global temperatures were caused by the burning of fossil fuels.

And the Senate still has not got it,

the British newspaper The Guardian lamented last January, when the Senate near-unanimously voted that global warming was indeed real, but refused to link it to human activity. Researchers at Yale University estimate that 48 percent of Americans share their refusal to pin blame on our own behavior, even if, as the NSEE found, just 16 percent reject that the climate is changing, period, the lowest percent ever. 

‘Belief’ in global warming was split along party lines, with 79 percent of Democrats finding it highly plausible while only 56 percent of Republicans agreed. The number of Republicans who flat-out deny evidence that the Earth's surface is heating up fell dramatically from just last year, from 41 percent to 26 percent.

Republican candidates’ timidity about the topic seems to reflect this uncertainty. While several acknowledge the phenomenon, and many are willing to venture that human activity plays some role, most shy away from pointing fingers. It’s “arrogant” to say we understand the causes, Jeb Bush believes, while Ted Cruz maintains “it ain’t happening.”

Feeling chilly, and annoyed, in Los Angeles in 2013, Donald Trump tweeted

His 140 characters reflect two puzzles about Americans’ views on the issue.

First, many of us rely on first-hand experience – what the thermometer says at home – to inform our opinion on a global phenomenon. Cold winter? Climate change starts to sound less convincing.

But NSEE researchers noted that just one third of those who deny climate change reported being heavily influenced by the weather in their region, a record low down from previous majorities.

So what else is shaping our views? In addition to ongoing stories like glacial melt, 61 percent of respondents said that California’s $2.74 billion drought is a major influence – a problem scientists say is due, in part, to rising temperatures around the globe. 

But a bigger puzzle remains.

Global warming opinions are often framed as a matter of education and scientific literacy: the reasoning that perhaps the data is just too difficult.

But it turns out that it’s not so unusual for Ivy League grads like Mr. Trump to question scientists’ consensus that human activity is driving global warming, and presents a major dilemma.

A team headed by Yale professor Dan M. Kahan found little correlation between people’s scientific knowledge and their belief that climate change is a “serious threat.” 

Intelligent people are “even better at picking out the confirming data to support your beliefs,” science writer Michael Shermer said in discussion with Dr. Kahan during a Freakonomics interview. 

And the motive to do so? Fitting in.

Most folks want to “maintain a view that’s consistent with the one that’s dominant within their cultural group,” Dr. Kahan said.