Our 5 most-read fact-checks from November

Here’s an early gift for you this holiday season: Our five most popular articles from November.

5. Fact-checking Bernie Sanders' comments on climate change and terrorism

Sen. Bernie Sanders doubled down on his belief that climate change poses the greatest threat to national security at the Nov. 14 Democratic presidential debate in Iowa.  

"In fact, climate change is directly related to the growth of terrorism," Sanders said.

Because the link between climate change and terrorism is more indirect than Sanders described, we rated his claim Mostly False.

While there is a body of literature backing his broader point that climate change contributes to the growth of terrorism, Sanders overstated the "direct" connection. And there are, of course, many other factors that contribute to terrorism, including religious and ethnic tensions and political repression.

Experts and the Pentagon prefer to say that climate change is a "threat multiplier." Climate change can lead to food and water scarcity, which may in turn increase poverty, the spread of disease, and mass migration — in short, instability. In places with already weakened governments, this breeds the conditions for terrorism to thrive.

4. PolitiFact Sheet: 5 questions about Syrian refugees  

The terror attacks in Paris spurred intense debate over Syrian refugees and whether admitting them poses a threat to national security.

Thousands of civilians have fled Syria to escape the conflict that has killed more than 200,000 people. Some experts say the migration represents the largest humanitarian crisis since World War II.

After the attacks, more than 30 U.S. governors said they were against admitting refugees into their states out of concern that some civilians seeking asylum might actually be terrorists.

In this article, we answered five questions about Syrian refugees coming to the United States, including how many Syrian refugees are already in the United States, how many President Barack Obama has said we would accept, the background check system, and whether governors can halt refugee admissions.

3. What Barack Obama said about ISIS being contained

Obama’s critics went after him for using the word "contained" in talking about the Islamic State after the terrorist attacks in Paris.

Lost amid the uproar was context.

White House deputy national security adviser Ben Rhodes defended Obama’s remarks by saying, "The president was responding very specifically to the geographic expansion of ISIL in Iraq and Syria."

Rhodes’ statement rates True.

Rhodes has a point: In the context of Obama’s Nov. 12 interview with ABC’s George Stephanopoulos, it’s quite clear that Obama was narrowly talking about ISIS’ territorial expansion in Iraq and Syria. He did not rule out the potential for a terrorist attack, and he also made it clear that the United States’ anti-ISIS efforts are a work in progress.

"What is true is that from the start, our goal has been first to contain, and we have contained them," Obama said. "They have not gained ground in Iraq. And in Syria they'll come in, they'll leave. But you don't see this systematic march by ISIL across the terrain."

The idea that Obama claimed ISIS no longer presents an active threat is incorrect.

2. Ben Carson’s Pants on Fire claim that no signer of the Declaration of Independence held office

Republican presidential candidate Ben Carson posted a note on Facebook to rebut critics who say his lack of experience in elected office would be a serious obstacle to his serving as an effective president.

To bolster his point, the retired neurosurgeon wrote, "Every signer of the Declaration of Independence had no elected office experience."

Carson soon changed the post to read, "Every signer of the Declaration of Independence had no federal elected office experience" (emphasis added).

Both the initial and the revised versions of Carson's claim are far off base. We rated Carson's claim Pants on Fire.

About half or more of the declaration's signers had held elective office previously, including well-known figures such as Thomas Jefferson, Benjamin Franklin, John Adams, Samuel Adams and John Hancock. This reality severely undercuts Carson's overall point that the drafting of the Declaration of Independence showed how a lack of political experience can produce landmark political achievements.

Adding the word "federal" makes the claim nonsensical, as there was no federal government prior to the signing of the declaration.

1. Fact-checking Trump's claim that thousands in New Jersey cheered when World Trade Center tumbled

Arguing that there are terrorist sympathizers in the United States, Donald Trump says he saw "thousands" of New Jerseyans celebrating after the attacks on Sept. 11, 2001.

"I watched when the World Trade Center came tumbling down," the Republican presidential candidate said at a Nov. 21 rally in Birmingham, Ala. "And I watched in Jersey City, N.J., where thousands and thousands of people were cheering as that building was coming down. Thousands of people were cheering."

"It was on television. I saw it," Trump said the next day.

We conducted an exhaustive search of newspaper and television transcripts from the months after 9/11. While we found widely broadcast video of people in Palestine celebrating, we found nothing to corroborate Trump’s version of events on American soil.

Instead, all we could find is a couple of news articles that describe rumors of celebrations that were debunked or unproven.

There isn’t a shred of truth in Trump’s provocative claim, so we said Pants on Fire!