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A Project of The Annenberg Public Policy Center

FactChecking Science in 2016

SciCheck likely will have no dearth of false and misleading claims to cover next year, when a new Congress convenes and takes up the agenda of President-elect Donald Trump. The incoming president has vowed to reverse eight years of Democratic policies, and he has a Republican majority in Congress to help him accomplish his goals. 

But, for now, here are some of the more questionable science-related claims from 2016 on topics such as climate change, Zika, GMOs, marijuana and the human mind.

Climate Change

Scientific Consensus: Both the president-elect and his nominee for the head of the EPA, Scott Pruitt, made two of the most common false claims about climate change — that scientists disagree about both the connection and extent of climate change that’s due to human activity. Trump made his claims in November and Pruitt back in May. Numerous surveys of thousands of climate scientists have found that about 97 percent of them believe global warming is real and human activity is the main cause. The United Nations’ Intergovernmental Panel on Climate Change also concluded in its fifth assessment report, published in 2013, that it’s “extremely likely” that more than half of the global temperature rise since 1950 is due to human activities.

Trump on Climate Change, Nov. 23

The Facts on Trump’s EPA Nominee, Dec. 14

Climate Science, Not Pseudoscience: Ted Cruz said in January that “climate change is the perfect pseudoscientific theory because it can never, ever, ever be disproven.” That’s false. For example, if researchers found strong evidence to suggest gases like carbon dioxide don’t trap the sun’s heat (the greenhouse effect), then climate change would be disproven. But the likelihood of this occurring is minute because the greenhouse effect has been verified time and again since it was first proposed in 1824. In fact, part of that verification includes the design of heat-seeking missiles, which relies on an understanding of the greenhouse effect.

Cruz’s ‘Pseudoscientific’ Climate Claims, Feb. 1

No Warming ‘Halt’: Rep. Lamar Smith, the chairman of the House Committee on Science, Space, and Technology, claimed in March that a study published in Nature Climate Change “confirms the halt in global warming.” That’s false. The authors of the paper write, “We do not believe that warming has ceased.” Scientists disagree over the extent of a potential slowdown in the rate of global warming, but there is no evidence for a full-on warming halt. Smith also made a similar claim last year.

Smith Still Wrong About Warming ‘Halt,’ March 30

The Zika Epidemic

Blinded by Zika: Senate Minority Leader Harry Reid falsely claimed that Zika “affects everyone” because recent research found that it “causes people to go blind.” Temporary vision impairment is a symptom of Zika, a virus primarily spread by mosquito bite, but no adult has gone blind because of the virus. In fact, many people who contract Zika have little to no symptoms. However, it’s important to note that studies have shown that women who contracted Zika while pregnant have given birth to babies with severe vision impairment. Reid made his claim, and other similar claims, during a partisan battle over funding to combat the Zika epidemic.

Does Zika Cause Blindness?, Sept. 20

No U.S. Epidemic: In April, also during the debate over Zika funding, North Dakota Sen. Heidi Heitkamp warned about traveling in the U.S., claiming that the Zika virus will be transmitted “everywhere in the United States.” At the time, the Centers for Disease Control and Prevention projected local clusters of Zika transmission on U.S. soil via mosquito bite, but not a widespread epidemic. As of Dec. 7, the CDC’s projections have held true. Puerto Rico primarily, but also the U.S. Virgin Islands, Florida, American Samoa and Texas have seen locally acquired cases, the CDC reports. Every state in the continental U.S. has seen travel-associated cases, however, which means those residents contracted the virus in areas of local transmission out-of-state.

What Zika Means for Americans, May 6


Legalization: Libertarian presidential candidate Gary Johnson said in August that “marijuana-related” traffic deaths, hospital visits and school suspensions in Colorado have “not significantly” increased since the state legalized the drug. Reports do show substantial increases, but data limitations make it impossible to know how many cases were directly caused by marijuana. On traffic accidents — unlike alcohol, a positive test for marijuana doesn’t entail intoxication at the time of an accident. The drug can stay in a person’s system longer than its effects. On hospital visits — medical billing codes for marijuana signify a “marijuana-related” hospital visit in reports. But these codes don’t prove the drug was the reason for the visit, and one Colorado doctor said they are often assigned arbitrarily. On school suspensions — the Colorado Department of Education collects data on drug-related suspensions in general, so it’s not clear that the increase was due solely to marijuana.

Unpacking Pot’s Impact in Colorado, Aug. 19

Medical Research: In April, Democratic presidential candidate Hillary Clinton said that “you can’t do any research about” marijuana because it’s a Schedule I drug. That’s false. Schedule I classification makes it difficult to conduct research on a substance, but not impossible. For example, the Center for Medicinal Cannabis Research, based out of the University of California, San Diego, says its mission is to coordinate “rigorous scientific studies to assess the safety and efficacy of cannabis and cannabis compounds for treating medical conditions.”

Clinton on Marijuana Research, April 22

Water Issues

California’s Very Real Drought: Trump falsely suggested in May that “there is no drought” in California because the state has “plenty of water.” The state is in its fifth year of a severe “hot” drought, the type that’s expected to become more common with global warming. Trump also said water is being shoved “out to sea” to protect a “three-inch fish” at the detriment to farmers. But the state’s officials release fresh water from reservoirs primarily to avoid salt water contamination to agricultural and urban water supplies.

Trump’s Dubious Drought Claims, June 9

Fracking Fray: Sen. Jim Inhofe, chairman of the Senate environment committee, falsely claimed in November that a new report “confirms” that fracking “has not impacted drinking water” in Wyoming. The industry-funded report couldn’t reach “firm conclusions” due to a lack of water quality data before oil and gas exploration. The U.S. Environmental Protection Agency also found numerous issues with the draft report, some of which weren’t resolved in the final version. For example, the report didn’t conclusively determine whether the sources of water contamination were naturally occurring or caused by humans in some cases. 

More False Claims About Fracking, Dec. 2


Trump and His Hairspray: In May, Trump falsely said that using hairspray in his apartment, “which is all sealed,” would prevent banned ozone layer-depleting chemicals from escaping into the environment. But these chemicals, chlorofluorocarbons, would still make their way out, multiple experts said. Trump made his claim while also arguing that “hairspray’s not like it used to be” due to the CFC ban. Experts also said these global bans didn’t effect the quality of hairspray. These global bans appear to be reversing damage done to the ozone layer. The ozone layer protects the Earth’s inhabitants from the sun’s ultraviolet radiation, which is linked to skin cancer and other problems. Located between 6 to 30 miles above the planet’s surface, the ozone layer differs from ground-level ozone.

Trump on Hairspray and Ozone, May 17

Ozone and Asthma: Louisiana Rep. Ralph Abraham claimed in June that “thousands of studies” refute the U.S. Environmental Protection Agency’s conclusion that ground-level ozone exacerbates asthma attacks. That’s false. A link between ground-level ozone and asthma exacerbation is well-documented in the scientific literature, which both the American Lung Association and the World Health Organization acknowledge. Ground-level ozone is a component of photochemical smog, which is produced when sunlight reacts with various air pollutants. The sources of these pollutants include coal power plants, paint and cleaning products, and car exhaust.

Distorting the Ozone-Asthma Link, July 6

The Human Mind

Ineffective Torture: Trump said both in February and July that enhanced interrogation, or torture, “works.” But scientists have shown that the stress and pain induced by techniques like waterboarding can impair memory, and, therefore, inhibit a person from recalling information. Stress causes the release of hormones like cortisol, which impair the function of brain regions vital to memory formation and recall, sometimes even resulting in tissue loss. Scientists also point out that it’s difficult to know whether the information provided is true. It is not clear what policy on torture Trump will support as president. His choice for defense secretary is James N. Mattis, a retired Marine Corps general. Trump said that Mattis told him he has never found torture to be useful, the New York Times reported in November.

Trump on Torture, July 28

Implicit Bias for All: Vice President-elect Mike Pence implied in October that Hillary Clinton was wrong when she cited the fatal shooting of a black man by a black cop as a case of implicit, or unconscious, bias. But research shows African Americans are not immune to implicit bias against members of their own racial group. Implicit bias refers to unconscious and automatic features of judgment, while explicit bias entails conscious judgments. Thus, a person could explicitly believe that white and black Americans should be treated equally, but implicitly judge situations counter to that explicit belief. A group of Harvard scientists found “even numbers of Black respondents showing a pro-White bias as show a pro-Black bias.”

FactChecking the VP Debate, Oct. 5

Other Notable Claims

Ninth Month, Final Day: Trump claimed during the final presidential debate in October that under Clinton’s position on abortion, “you can take the baby and rip the baby out of the womb in the ninth month on the final day.” First off, Clinton had said she was open to restrictions on late-term abortions, with exceptions for cases involving the mother’s health issues. Second, abortions on the “final day” don’t occur. Daniel Grossman, a professor of obstetrics and gynecology at the University of California, San Francisco told Politifact, “Nobody would talk about abortion on the woman’s due date. If the mother’s life was at risk, the treatment for that is delivery, and the baby survives.” Third, late-term abortions in general are rare, as only 1.2 percent of all the abortions in the United States occur after 20 weeks gestation, according to the Guttmacher Institute.

FactChecking the Final Presidential Debate, Oct. 20

Birds and Wind Farms: Trump said in May that wind farms in the U.S. “kill more than 1 million birds a year.” Reliable data are scarce, but current mean estimates range from 20,000 to 573,000 bird deaths per year. In his claim, Trump also misleadingly compared bird deaths at oil drilling operations with those at wind farms. But a 2012 Bureau of Land Management memo states that oil field production kills an estimated 500,000 to 1,000,000 birds a year. This suggests oil production alone (i.e. not including the production of coal or gas) can kill the same, if not more, birds per year than wind farms in the U.S. Even still, there are greater threats to birds than energy production, including cats and buildings.

Trump’s Hot Air on Wind Energy, June 2

Frankenfish: Alaska Sen. Lisa Murkowski said in March that she opposes federal approval of genetically engineered salmon “for the health of both consumers and fisheries.” But no scientific evidence suggests GE salmon will pose a significant risk to either. Scientists engineered GE salmon to grow faster than non-GE farm-raised salmon by inserting genes from two other fish into the genome of an Atlantic salmon. With these changes, the GE salmon remained nutritionally and physiologically comparable to non-GE salmon, so the Food and Drug Administration deemed GE salmon “safe to eat.” GE salmon have also been rendered sterile — meaning they can’t interbreed with wild salmon stocks. Geographical and physical confinement measures also limit the likelihood that the GE fish will escape, survive and impact wild fisheries.

False Claims About Frankenfish, March 23

Editor’s Note: SciCheck is made possible by a grant from the Stanton Foundation.