Scientific findings—and a lack of them—played a starring role in a controversial decision earlier this week by Democratic New York Governor Andrew Cuomo to essentially ban the natural gas extraction technique known as fracking in the Empire State.

The 17 December decision rested heavily on a state health department report that reviewed dozens of studies of the potential human health impacts of oil and gas development and found cause for concern. “I looked at this process with the same critical eye I always use in medicine,” said Howard Zucker, a physician and New York’s acting health commissioner, at a Cabinet meeting that covered the issue. During the discussions, Zucker displayed numerous scientific papers that he said highlighted how multiple facets of shale gas production, including drilling, trucking, and wastewater disposal, could potentially harm human health. He also lamented a lack of data on some risks. Precaution was the best course, Zucker suggested in recommending a hydraulic fracturing, or fracking, ban.

Cuomo said he was only heeding expert advice in making the move, which makes permanent a temporary fracking moratorium the state has had in place since 2008. “I’m not a doctor, I’m not an environmentalist, I’m not a scientist,” he said. “So let’s bring the emotion down, and let’s ask the qualified experts what their opinion is.”

Not surprisingly, the decision is drawing divided reaction.

It is “a great example of science trumping politics,” Gretchen Goldman, lead analyst for the Center for Science and Democracy at the Union of Concerned Scientists in Washington, D.C., told ScienceInsider. Cuomo “took the right step in looking at the evidence and making a decision based on scientific information that was presented to him.” (The group doesn’t have an official stance on fracking, although it has raised concerns about the potential risks.)

Industry groups see things differently. “When discussing just about every one of these dubious studies, [the New York State Department of Health] admits that they actually didn’t have any evidence to link hydraulic fracturing to health impacts,” wrote Katie Brown, a blogger for the Independent Petroleum Association of America outreach group Energy In Depth. (Industry groups have seized on some recent findings that leaky wells, and not the fracturing process itself, might be responsible for tainted ground water in certain places.)

Fracking is a technique that has been used in various forms for decades. Drillers pump a mixture of water, sand, and chemicals underground at high pressure to break up hydrocarbon-bearing rock, releasing trapped oil and gas. In recent years, technological advancements have enabled firms to use horizontal, and not just vertical, drilling to exploit rock formations once out of reach, including the gas-rich Marcellus Shale formation across New York and Pennsylvania. Although fracking has boomed in Pennsylvania, officials across the state line in New York have been leery and taken a go-slow approach.

Technically, Cuomo’s ban doesn’t apply to all fracking. It targets so-called high-volume hydraulic fracturing (HVHF), which uses large quantities of fluids to crack the horizontal rock layers in shale beds. In practice, however, the ban—which applies to wells using more than a certain amount of fluid—will eliminate the most attractive sites because drillers now won’t “have enough water” to operate effectively, says Robert Jackson, a professor of environmental earth system science at Stanford University in Palo Alto, California.

The health department’s full case for the ban is laid out in a report that summarizes existing information on HVHF-related oil and gas operations’ impacts to water, air, soil, and communities. It cites scores of scientific papers, government documents, anecdotal reports, and environmental assessments.

The report highlights a range of impacts that extend well beyond the fracking process itself. It notes “[a]ir impacts that could affect respiratory health,” for example, and “[c]limate change impacts due to methane and other volatile organic chemical releases.” Drinking water could be contaminated by “underground migration of methane and/or fracking chemicals associated with faulty well construction.” Surface spills could taint soil and water, and “inadequate wastewater treatment” could leave water supplies polluted. The report also mentions “[e]arthquakes induced during fracturing" and “[c]ommunity impacts” such as increased trucking traffic, more accidents, and noise.

At the same time, “it is apparent that the science surrounding HVHF activity is limited, only just beginning to emerge, and largely suggests only hypotheses about potential public health impacts that need further evaluation,” the report says.

Amid that uncertainty, the debate over fracking impacts is likely to continue. The ban amounts to “a politically motivated and equally misinformed ban on a proven technology,” said Karen Moreau, executive director of the American Petroleum Institute’s New York State Petroleum Council, in a statement. But Kate Sinding, director of the Community Fracking Defense Project at the Natural Resources Defense Council, an environmental group based in New York City, said in a statement that “[m]ounting scientific evidence points to serious health risks from fracking operations. … New Yorkers have made it loud and clear that we want to keep this reckless industry at bay.”

Although HVHF is banned in New York for now, that doesn’t mean that all hope is lost for the oil and gas industry in the state, says Stanford’s Jackson. “The oil and gas aren’t going anywhere,” he says, should the ban ever be reversed. “I think it’s a cautious approach. I’m surprised … but it’s a fascinating decision,” because of the ripple effect it could have domestically and abroad.

Susan Christopherson, an economic geographer at Cornell University, agrees. “I think the governor weighed the politics and economics as well as the science,” she said in a statement. “I think he weighed the pros and cons and determined that fracking is not a good deal for New York. Now, New York’s deliberative process and citizen action are a model for addressing fracking internationally.”