Climate change: the Readers' Choice winner

Climate change was in the news this year, starting with the polar vortex at the beginning of 2014 and continuing with the Keystone XL pipeline and proposed carbon-cutting regulations on power plants.

But what stuck with readers were the claims that flat-out denied climate change science. The statement "Climate change is a hoax" won PolitiFact’s annual Readers' Poll for Lie of the Year with 31.8 percent of the vote.

That claim was the title of a five-minute video released by congressional hopeful Lenar Whitney, a Republican from Louisiana. Several climate scientists told PolitiFact that Whitney’s claim was "laughable," "deeply misguided," "uninformed," "disgusting" and "absurd." We called it Pants on Fire. Whitney, meanwhile, didn’t even make the run-off.

Here, then, are other highlights from our fact-checks about climate change in 2014.

The hoax

Politicians with much higher profiles than Whitney also have argued with basic climate change science, such as Sen. Marco Rubio, R-Fla., a potential 2016 presidential contender. He said in May that human activity is not "causing these dramatic changes to our climate." We rated that claim False.

How do we know climate change isn’t a mass conspiracy to pull the wool over the world’s eyes, as Whitney and others claim?

Such a scenario seems near impossible, considering the overwhelming consensus among respected climate scientists that anthropogenic (human-caused) global warming is indisputable.

Research also shows that climate change denial is concentrated among those who have less expertise in the subject or no scientific training at all.

Additionally, much of climate change deniers’ back-up evidence is cherry-picked or too simplistic to be meaningful.

For example, Rubio said Earth’s surface temperatures "have stabilized," a claim we rated Mostly False. He has a point that there has been a pause in temperature growth over the past 15 years. But scientists say it’s far too early to say temperature has stabilized, and most believe growth will pick back up again. Additionally, the past 15 years have been some of the hottest years on record, despite the pause in temperature growth.

Some deniers turn the tables and say it’s the government and its scientists that are spinning the data. In June, Fox News pundit Steve Doocy said, "NASA scientists fudged the numbers to make 1998 the hottest year to overstate the extent of global warming."

First of all, Doocy distorted the blog post where he took the claim from. Second, scientists found fundamental flaws in the raw data used to make this claim. We rated Doocy’s claim Pants on Fire.

Climate science acceptance 

Compared to the consensus among scientists, the percentage of Americans who believe in human-caused climate change is quite low. The latest Gallup polls for 2014 show that 25 percent of Americans are skeptical of global warming, while 40 percent are "concerned believers" in global warming.

Among skeptics, according to the poll, 80 percent of skeptics are Republicans, and 11 percent are Democrats. This partisan split carries over into Washington, said California Gov. Jerry Brown, who claimed "virtually no Republican" in Washington accepts climate change science. After finding fewer than 10 current Republican politicians who accept the science, we rated Brown’s claim Mostly True.

This will eventually cause problems for Republicans trying to court young people, said Sen. Chris Murphy, D-Conn. He said "only 3 percent of voters 18 to 34 don't believe that climate change is really happening." Murphy’s claim matched up with polling data, and we rated his claim True.

Conservative radio talk show host Rush Limbaugh took pride in the fact that so many Americans share his skepticism of climate change science -- saying the United States leads "with the highest amount of doubt about the conventional wisdom of climate change" in the world. Taking into account some caveats about the research, which polled people in 20 countries, we found Limbaugh’s claim to be Mostly True.

But in some ways, the United States leads the world in its efforts to stop climate change, said President Barack Obama in his 2014 State of the Union. He said the United States is No. 1 in the world for reducing its carbon emissions, which would lower the level of greenhouse gases that scientists say cause global warming. That’s true in raw numbers. However, the United States is not at the head of the pack when considering the scale of the cuts proportionally -- how much carbon a country cuts relative to how much it emits. For that, we gave Obama’s claim Half True.

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