Few things have inspired angst among green groups and climate advocates like the question of how to deal with fracking. It's been one of the more important discussions within environmentalism over the last few years.

Here's a very rough breakdown of the debate: Supporters of fracking point out that the US natural-gas boom, driven by hydraulic fracturing, has actually been one of the big environmental success stories of the past decade. Electric utilities are now using more cheap gas and less dirty coal to generate power. Since gas burns more cleanly, that curbs air pollution: US carbon dioxide emissions have plunged roughly 10 percent since 2005.

A big debate: Should fracking be regulated more tightly — or banned?

That, in turn, has given momentum to President Obama's big push to tackle global warming and curtail power plant emissions further via EPA regulations. "You have to ask," Michael Levi of the Council on Foreign Relations told me last fall, "does the emergence of a cheap, reliable option for cutting emissions make regulators more willing to force power plants to cut their emissions? And the answer is yes. We're seeing that play out."

Green-minded supporters of fracking usually concede that there are real problems with the practice — like water pollution — but they often focus more on patching those problems than on banning it altogether. Advocates of this approach include the Environmental Defense Fund, as well as, crucially, the Obama administration.

On the "anti" side, meanwhile, are a large and growing set of environmentalists who now argue that the problems with fracking outweigh the benefits.* It's not just the air and water pollution caused by fracking. They also point out that there's methane leaking out of all those gas wells and pipelines. Methane is a potent greenhouse gas, and depending on how big those leaks are, they could offset the climate benefits of lower CO2 emissions.

Just as significantly, those more skeptical of fracking point out that natural gas is still a fossil fuel and produces carbon dioxide when burned (even if it's only half as much as coal). And if we want to avoid drastic global warming, we'll need to phase out most or all fossil fuels very soon. These groups are less keen on Energy Secretary Ernest Moniz's suggestion that natural gas can be a "bridge" to a cleaner future. They don't see gas as helping us move away from coal. They see cheap gas as hampering the transition to renewable sources like wind and solar.

The conflict around these different viewpoints have also spurred a recent, practical disagreement. Should activists push for tighter regulations around fracking to fix its downsides — or focus on trying to ban fracking altogether?

Green groups split over how to tackle methane leaks

That brings us to a fascinating story today in Inside Climate News, written by Lisa Song and Katherine Bagley, about an environmental rift over how to deal with methane leaks.

The overarching problem here is that no one knows how much methane is actually leaking out of natural gas infrastructure. It might be a lot — in which case natural gas could conceivably be worse for global warming than coal is. Or it might be a little, in which case natural gas would help efforts to tackle climate change. But it's unclear. Right now, the EPA is essentially guessing.

Some groups see methane regulations as legitimizing the industry

So one green group, the Environmental Defense Fund (EDF), decided to work with the oil and gas industry and a variety of scientists to actually measure methane leaks, publish the findings in scientific journals, and then figure out the best ways to plugs those leaks. EDF has raised some $18 million for the project ($12 million from foundations, $6 million from industry groups), and are in the midst of publishing 24 papers on the topic.

As Song and Bagley report, this work has been very controversial with a large number of other environmentalists and anti-fracking activists:

Working with gas companies deepened many environmentalists' longstanding frustration and mistrust of EDF, which has collaborated with industry on green issues for three decades. It further solidified the group's position as an outlier in the environmental movement. Unlike many green groups, EDF generally supports fracking with appropriate regulations, including a ban on the practice in sensitive areas. Critics charge that the methane studies may encourage expansion of a dangerous technology.

To be clear, no one is alleging that the scientific work EDF is overseeing has been tainted by its association with industry. Many of the scientists involved in these studies are highly respected, and they're collaborating with natural gas companies because that's the best way to get data that would otherwise be unavailable. The research appears sound.

Instead, there's a deep-seated strategic disagreement here. EDF seems to view the rise of gas fracking as inevitable (and, in some ways, a decent way to reduce carbon dioxide emissions in the short term). So a crucial next step is to figure out where those methane leaks are coming from and plug them up.

Toward that end, EDF was at the forefront of helping Colorado develop strict new rules in 2014 forcing oil and gas companies to install methane monitoring devices. And EDF has been helping the Obama administration in developing a federal plan to curtail methane leaks from oil and gas wells.

Other green groups, by contrast, see EDF's work as lending legitimacy to the natural gas industry. They want fracking phased out as soon as possible, not made sustainable. And, for their part, anti-fracking activists had some success with a harder approach — last year, after much debate, New York state decided to ban fracking altogether, citing the health risks from local pollution.

As Song and Bagley document, this debate has become quite bitter. Here's one anti-fracking activist attacking EDF:

The [Colorado] regulations "were just another public pacifier," said Shane Davis, a Colorado-based fracking activist. "Grassroots communities have gotten so astute on who the enemy is. It's not just the governor that supports fracking. It's not just the industry. It's these people who come in in sheep's clothing, but are wolves, like EDF. EDF should stand for 'environmental defense fraud.' They're absolute sellouts."

Here, by contrast, is a different take from another green group — it's all well and good to push for bans, but in the meantime, it's still worth working for stricter regulations:**

"Bans and moratoriums are few and far between relative to where oil and gas is being drilled and produced in the United States," said Bruce Baizel, the Colorado-based director of Earthworks' energy program. "What do you do in the meantime while you're trying to work on a ban? Kids are getting sick. Moms can't live in their houses. You've got to try to straddle both sides."

All sides here seem to be genuinely interested in reducing pollution — but they have quite different views on how to get there.

At the same time, these various strategies do seem to complement each other. If energy companies are worried about activists (and voters) pushing for a total ban, they're more likely to turn to groups like EDF that can push for tighter regulation and help ease the backlash. So at least in that respect, this debate already seems to be having an important effect on the industry.

Foot notes

* On Twitter, David Turnbull of Oil Change International says that the "vast majority" of green groups he's seen are now generally anti-fracking. That jibes with my impression, although I haven't done a formal tally. It also might be more precise to see this as a spectrum.

Some anti-fracking activists want to stop all fracking, period. The Sierra Club has called for a moratorium on fracking in states like Pennsylvania, West Virginia, and Michigan, but also calls for stricter regulations. Meanwhile, the Clean Air Task Force tends to focus on regulations but also supports bans in some places (see below). Then there's the Environmental Defense Fund, which has called for tighter regulations, but generally doesn't call for banning the practice.

Update: Clean Air Task Force emailed with a clarification of its position: "Clean Air Task Force takes issue with the premise that organizations can either be for regulations or for bans. Pollution-cutting policies are urgently needed to safeguard the climate and the health of communities impacted by ongoing oil and gas development. Pressing for such policies does not preclude organizations from also supporting bans. While Clean Air Task Force advocates for strong nationwide standards to mitigate methane pollution and other impacts of oil and gas development, the group also supports making some areas totally off limits to this activity."

I've updated their place on the spectrum accordingly.

** I've also clarified Earthworks position — that quote in the piece wasn't intended as a defense of EDF, but rather as a defense of pushing for regulations in places where fracking was already going on.

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