Methane and HFCs: Milestones on the Pathway to Safer Climate

Curbing methane and HFCs is critical to protecting our climate

This is part of a series of blogs on NRDC’s new report, “America’s Clean Energy Frontier: The Pathway to a Safer Climate Future”

NRDC’s new report, America’s Clean Energy Frontier, outlines a cost-effective pathway to a safer climate future.  Based on comprehensive modeling by NRDC and Energy + Environmental Economics (E3), the report shows how we can cut U.S. emissions of climate-changing pollution at least 80 percent from 2010 levels by 2050.

These U.S. emission reductions are a necessary part of global efforts to keep the increase in average global temperatures exceeding 2 degrees C—the target scientists say we must meet to avert the worst effects of climate change.

We can make the necessary reductions in America’s climate pollution using proven clean energy solutions that are available today. Ninety percent of the emissions reductions in our pathways report come from aggressive deployment of known technologies for energy efficiency, renewable energy and electrification of vehicles and most energy uses in buildings.

These measures focus on reducing carbon dioxide (CO2) emissions, and rightly so. Once emitted to the atmosphere, CO2 lingers for centuries, much longer than many other greenhouse gases, and causes more than 80 percent of total climate damage. 

But other heat-trapping pollutants are also important, and NRDC’s report addresses how we can cut their contribution to climate change. NRDC’s analysis shows how we can cut these non-CO2 pollutants by more than 55 percent compared to expected business-as-usual levels in 2050 (or almost 30 percent below 1990 levels).

Here we focus on two of these pollutants—methane and hydrofluorocarbons (HFCs)—that will make a big difference in the global temperatures we experience in our lifetime and the lifetime of our kids.  

Compared to CO2, methane and HFCs are short lived.  On average, they last about a dozen years in the atmosphere.  But during their short lifetime, they pack a mean punch. Pound for pound, methane is 35 times more damaging than CO2 over a century, and 86 times more potent over a 20-year period.  HFC-134a, the most common HFC, is a whopping 1300 times more powerful than CO2 over 100 years. 


Methane leakage from the oil and gas industry is our second largest industrial contributor to climate change. Curbing oil and gas methane leakage is a critical component of our pathways report. As we detail in an earlier report, entitled Waste Not, and developed together with the Clean Air Task Force and Sierra Club, within a decade the oil and gas industry can cut its methane emissions nearly in half from 2012 levels by widely deploying available, low-cost measures that are already in use by many leading companies today. What are those measures?

At the top of the list are leak detection and repair programs to find and fix the multitude of leaking valves and other components throughout the supply chain. In addition, industry can replace existing, leaky devices throughout its production and pipeline system with components that leak little or no methane. 

And companies can cut venting and flaring of methane gas in production fields by capturing and using gas they are currently allowing to escape, either using the gas to power their production operations or keeping it in the pipes and sending it to market.  

These measures reduce methane pollution and cut down on leakage of smog-forming and cancer-causing chemicals at the same time. They can be employed not only at new sites, but also on current operations. They often result in a net savings to companies due to proceeds from gas delivered to market instead of leaked to the air.

Regulations in leading states such as California, Colorado and Wyoming are demonstrating that the oil and gas industry can successfully curb its pollution. 

Unfortunately, President Trump and Environmental Protection Agency Administrator Scott Pruitt are bent on repealing the agency’s 2016 standards that curb methane leakage from new oil and gas operations. NRDC and our partners won a court victory in July, beating back his first attempt, and we are continuing defending those rules. We’ll also soon be in court pushing the EPA to expand the rules to cover methane leakage from current operations. 


Hydrofluorocarbons (HFCs), with thousands of times the heat-trapping power of CO2, are also the world's fastest growing climate pollutants, increasing globally by more than 10% per year. 

HFCs are used as refrigerants in air conditioning and refrigeration systems, as well as in plastic foams, aerosols, and more applications. HFCs leak from these household products when they are used, serviced, and discarded.

In October 2016, along with about 150 other countries, the United States signed the Kigali Amendment to the Montreal Protocol, a global agreement to phase down HFCs. Under the agreement, the U.S. committed to reduce the production and use of HFCs by 85 percent from 2011-2013 levels by 2036, with the first cuts coming in the early 2020s. NRDC’s pathways report models HFC emission reductions in line with that cap.

Here at home, we can cut HFC emissions first by replacing them wherever there are alternatives that are safer for the climate. Congress enacted the Clean Air Act’s Safe Alternatives program to do just that. That program is in jeopardy, however, due to a decision last month by divided panel of the federal court of appeals in Washington.  NRDC is asking the full appeals court to correct that ruling. 

The Clean Air Act also requires industry to stop HFC leaks during use, servicing, and maintenance of air conditioning and refrigeration systems. These rules are also under court challenge, and NRDC is working to assure that they survive.


The pathway to a safer climate includes curbing more than CO2. We can, and must, cut all of the heat-trapping pollutants that are driving dangerous climate change.  

This post co-authored with Meleah Geertsma and Alex Hillbrand