Earlier this month, the Democratic Platform Committee rejected attempts to add a “ban fracking” plank. The plan’s final draft will be presented for approval this week at the Democratic National Convention. Bernie Sanders, in an e-mail to supporters after his convention speech, promised to continue fighting for a “national fracking ban.”

The tussle over the “ban fracking” plank misses the point. It is shale, not “fracking,” which burst onto the U.S. landscape at the turn of the century, first in Texas, then quickly spreading to Arkansas, Louisiana, and Pennsylvania, under the names Barnett, Fayetteville, Haynesville, and Marcellus. It is oil and natural gas from shale that have prolonged the fossil fuel era at a time when we should have been managing its inevitable end, and it is the production of shale hydrocarbons—using a combination of some new and some old technologies—that now pollutes our drinking water, causes local air pollution, and exacerbates climate change through emissions of carbon dioxide and methane.

Fred Krupp of the Environmental Defense Fund calls natural gas “an exit ramp, not a bridge.” And during the April Democratic debate, Hillary Clinton quickly declared, “So we did say natural gas is a bridge. We want to cross that bridge as soon possible, because in order to deal with climate change, we have got to move as rapidly as we can.” They’re both right: that bridge is a bridge too far, and we need to move rapidly on climate.

Platforms, planks, exit ramps and bridges. As a civil engineer, I can easily design them all. But political platforms and planks are not so easily designed, and exit ramps and bridges are shorthand metaphors for complex ideas. Like “fracking,” these words are buzzwords; the sound-bite political jargon of industry insiders, environmentalists, commentators, journalists, and private citizens alike.

As a fracture mechanician, I can, and have, taken both gas industry spinmeisters and environmental activists to task for their unscientific use of the word “fracking.” Words matter. So do specificity, science, math and evidence. It is the height of cynicism to play semantic games with the word “fracking” in order to sidestep the many related problems—local, regional, national and worldwide—that must be seriously addressed by our political leaders. No, it is not the short-lived “fracking” technique itself that concerns me and banning “fracking” itself would have been a half-measure. Rather, we must address the effect of ancillary activities surrounding shale gas and oil exploration, development, and transport on the environment and our communities, particularly within the localities from which these hydrocarbons are extracted, and on our planet.

The harmful effects of what comes before and after fracking are indeed both local and global. In Pennsylvania alone, the Public Herald has uncovered over 1,200 formal complaints filed about water well contamination, and at least 280 positive determinations of such contamination by the state regulatory agency; more than 500 complaints remain unresolved. These ancillary activities also exacerbate climate change through emissions of carbon dioxide and methane.

It’s in the financial and political interest of shale gas boosters to extend the gas bridge out as far as possible and delay transition to renewable energy. Those who deny climate change outright or who want to wait for a cooler political climate in which to meaningfully act are happy to let them have their way. Unfortunately, however, all of us are out of time.

I can analyze data and come to conclusions based on hard numbers, and I can offer insight as to what the data suggest, but I can’t make policy. A thousand scientists can send a thousand letters to denialist Senators, but as the saying goes, it is only “when the student is ready that the teacher appears.”

Extreme weather is a hard teacher. And like climate deniers, those who support shale-gas exports through LNG terminals (thereby advocating natural gas as a decades-long bridge) are engaged in an exercise in magical thinking, willful ignorance or cognitive dissonance with regards to the emerging data on natural gas’s effect on climate change. We can exploit natural gas or we can truly address climate change, but we can’t do both, not in the decade or two we have left to act decisively.

In February, climate expert Joe Romm of Climate Progress wrote: “natural gas plants don’t replace only high-carbon coal plants. They often replace very low carbon power sources like solar, wind, nuclear, and even energy efficiency. That means even a very low leakage rate wipes out the climate benefit of fracking.”

Is natural gas, mostly methane, the cleanest fossil fuel with respect to climate change? No, it is not. For that to be true, the rate at which shale methane leaks into the atmosphere without being burned would have to be less than about 2.7 percent of total shale gas production. Before 2011, nobody had ever performed an objective, national scale, life-cycle measurement of leakage from well pads, fracking flowback, processing units, compressor stations, storage facilities, pipelines, and end-uses. In the five years since, many such measurements suggest that the current best estimate is that the leak rate is between 3.6-7.1 percent—close to what my colleagues and I at Cornell predicted in 2011.

Thus we have now learned not only that way too much methane is being leaked from the shale hydrocarbon production life-cycle, but that its climate-change impact has been underestimated. For decades, methane’s impact on climate change was estimated to be about 21 times that of carbon dioxide, if measured over a century. But recent new atmospheric chemistry research shows that the relative impact is greater than 30 times that of carbon dioxide. And it gets worse. The latest IPCC report says we no longer have a century to worry about climate tipping points: We have about 20 years, so we should be assessing the relative impact of methane over the next few decades. When we do that, the relative impact factor is over 80 times that of carbon dioxide. That few percent leak rate has a big impact on climate change over the crucial next two decades.

So far, science has had minimal influence on the climate-energy policy nexus. However, the atmosphere does not obey ham-handed international agreements; it obeys physical law. It does not postpone its complex chemical reactions to conform to a 100-years outlook or hopeful thinking, nor does it stop those reactions to make methane only 21 times worse than CO2. And instead of carefully managing the increase in the supply of, and demand for, renewable energy over the past 20 years, we have lost more than a decade to overblown hype claiming shale hydrocarbons boost “energy security” and “energy independence.”

If not a “ban fracking” plank, then what should be in the Democratic platform for energy policy and its inter-related environmental, human health, social justice, and climate change issues? Some of what was accepted in the platform in compromise to the defeated “fracking ban” addresses several of the points I have made in this commentary (italics are mine):

Democrats are committed to closing the Halliburton loophole that stripped the Environmental Protection Agency of its ability to regulate hydraulic fracturing, and ensuring tough safeguards are in place, including Safe Drinking Water provisions, to protect local water supplies. We believe hydraulic fracturing should not take place where states and local communities oppose it. We will reduce methane emissions from all oil and gas production and transportation by at least 40-45% below 2005 levels by 2025 through common-sense standards for both new and existing sources and by repairing and replacing thousands of miles of leaky pipes. This will both protect our climate and create thousands of good-paying jobs…During the clean energy transition, we will insure landowners, communities of color and tribal nations are at the table…We will streamline federal permitting to accelerate the construction of new transmission lines to get low-cost renewable energy to market, and incentivize wind, solar and other renewable energy over the development of new natural gas power plants.

What is missing from the platform is a plank that directly addresses the root cause, and a stronger plank addressing hydrocarbon extraction from public lands: Almost all new oil and gas wells are fracked, and many legacy wells are being re-stimulated by fracking. An immediate ban on all fracking would shut down almost all new oil/gas production, but we will need a predictable but decreasing supply of oil/gas over the next eight years. The best practical strategy is to phase out new shale gas/oil production from private lands, and let the legacy shale wells run dry. We should call for an immediate ban on all new leasing of public lands for shale oil and gas production, onshore and offshore, and especially the Arctic region.

Even without a “ban fracking” plank, the Democratic Party platform has been amended in response to shale hydrocarbon development in ways that are necessary from the perspectives of energy policy, public health, social justice, and climate change.

The renewable energy revolution already underway has us on the natural gas “exit ramp,” and we need to speed down that ramp “as rapidly as we can.” Incentivizing renewables and weaning from natural gas is the way to go. Let’s get to work.