Editor’s note: The number used in this blog post to describe the heat-trapping strength of methane compared with carbon dioxide, while accurate, has been updated with one that is more widely used among experts.

Throughout history, maps have played a critical role in shaping our decisions – helping us determine where we are going and how we are going to get there. Now, we’re using them to define a way to address climate change.

Environmental Defense Fund and Google Earth Outreach have worked together to launch a series of maps that show methane leaks from natural gas pipelines under city streets in Boston, Indianapolis and Staten Island.

This new tool has the power to greatly improve cities’ and utilities’ ability to minimize methane emissions that contribute to global warming.

Why care about methane?

A recent tide of scientific studies about losses from the natural gas supply chain has made it clear the critical importance of reducing methane emissions. Methane is the primary ingredient of natural gas.

One of natural gas’s potential benefits over other fossil fuels is that when burned it produces less carbon dioxide emissions, half as much as coal. If used wisely to rapidly displace dirty coal power plants, for example, natural gas could help the country dramatically reduce overall greenhouse gas emissions.

Unburned, however, methane is 84 times more powerful than carbon dioxide for the first 20 years after it is released. That means if too much methane escapes along the supply chain – anywhere between the well and the end user – it could postpone the climate benefits of fuel switching, a delay we can ill afford.

Roughly one-third of methane emissions in the United States come from the oil and gas industry, and one third of the warming we are currently experiencing comes from anthropogenically released methane in the atmosphere, thus addressing methane leakage in the natural gas supply chain is critical.

With great data comes great responsibility

For our analysis of methane emissions from local distribution pipes, Google equipped three Street View cars with methane analyzers and drove large portions of Boston, Staten Island and Indianapolis collecting methane concentration data every half second, GPS data and wind speed and direction.

Our science team, in partnership with Colorado State University researchers, developed a first-of-its-kind algorithm to translate the patterns of concentration data collected by the Street View cars into methane leak rates for individual leaks. This data and the accompanying maps are designed to help the public, utilities and regulators better understand the pattern and scale of urban methane leaks.

For example, we observed one leak per mile of road driven in Boston and Staten Island, a borough of New York City, and depending on the size of that leak the climate impact over the next 20 years ranged from the equivalent of driving a car 100 miles every single day up to driving more than 9,000 miles every day.

This data will allow utilities to better prioritize which leaks to repair or pipes to replace, enabling them to get rid of the larger leaks much faster than was possible before.

Prioritizing repairs and investment

Local utilities, such as National Grid whose service area includes Boston and Staten Island, helped validate the data and now have added insight into where their repair efforts should be targeted. Leaks even larger than those we saw in our surveys are of the greatest public safety concern; but those leaks are usually identified and fixed quickly.

Smaller leaks are monitored by the utilities, but can go unfixed for long periods of time, spewing significant amounts of climate pollutants into the atmosphere. The new methodologies developed to produce the maps hold the potential to benefit both public health and the climate.

In addition to providing a picture of leak rates across our cities, these maps clearly show the value of investing in a modern natural gas infrastructure. Older pipes made of cast iron and unprotected steel can corrode as they age, making them more vulnerable to leaks.

Plastic pipes, which are used in newer systems, are more durable over time and leak much less. The 200-times-lower frequency of leaks in Indianapolis, versus Boston and Staten Island, clearly indicates the value of upgrading to plastic pipes, as was done in Indianapolis. 

Investing in newer infrastructure pays off three fold:

1. It minimizes safety risks;
2. It benefits the climate;
3. It keeps a marketable product out of the air and in the pipeline.

In the early 80s, the utility Citizens in Indianapolis made replacing their aging pipelines a priority. Today, pipes vulnerable to corrosion makes up only one percent of Indianapolis’ local distribution system, and leak rates there were congruently low.

Our efforts found only five leaks in the pipelines examined – one leak for every 200 miles mapped. While Boston, where about half of the pipes are made of materials vulnerable to corrosion and have been in the ground for more than half a century, averaged roughly one leak per mile mapped.

EDF has focused on finding the ways that work for almost 50 years, and this collaborative mapping project is indicative of our commitment to tapping the power of science in pursuit of effective solutions. This project takes a major step toward providing local gas distribution utilities and regulators the scientific tools to better understand methane leaks and should spur meaningful local efforts to reduce emissions of climate pollutants.

It creates more opportunities for effective action. By continuing our collaborations with Google, CSU, local utilities and the public, we can broaden the scope of what we know, map more pollutants in more cities and spark more change for climate progress. 

Editor’s note: The number used in this blog post to describe the heat-trapping strength of methane compared with carbon dioxide, while accurate, has been updated with one that is more widely used among experts. 

Not all climate pollutants are created equal. That’s the case New York Times reporter Justin Gillis makes in his July 7 column, “Picking the Lesser of Two Climate Evils.”

Gillis quotes a prominent scientist who suggests that when it comes to climate change, controlling methane pollution should take a back seat to addressing carbon dioxide.

I believe that’s a false choice; there’s no reason to pick one or the other. In fact, any effective climate policy must target both.

That is the only way to achieve the maximum potential greenhouse gas reductions, and the maximum possible climate benefit in the near and long term.

We can’t afford to ignore methane…

There is no dispute that the most damaging long-lived climate pollutant is carbon dioxide, and about half of what is emitted will remain in the atmosphere – lasting at least a thousand years. While individual carbon dioxide molecules weakly absorb heat, they become collectively potent as they accumulate in the atmosphere over time.

On the other hand, methane – the most damaging short-lived climate pollutant – traps 84 times more heat than carbon dioxide for the first 20 years after being released, but only lasts for a decade or so in the atmosphere.

Each plays a different, yet critical role in negatively affecting the environment and triggering more intense storms and other extreme weather events.

Climate policy needs to ensure that we are addressing the impacts on people and ecosystems both today and 100 or more years from now. Reducing methane is essential to reducing near-term impacts; reducing carbon dioxide is essential for the long term.

To choose between them would be to trade off impacts among generations – an unacceptable choice.

Each plays a different, yet critical role…affecting the environment and triggering more intense storms and other extreme weather events.

Effective national climate policy can address both – the actions required are largely distinct and complementary.

More than a third of the warming we feel today is caused by short-lived climate pollutants including methane, which accounts for most of that amount. These emissions are intensifying already extreme weather patterns such as long droughts and high temperatures in many parts of the country and the enormous impacts we are witnessing with increasing frequency.

Working to reduce methane emissions is one of the most effective steps we can take to slow near-term climate change. Emissions of short-lived climate pollutants, such as methane, are essential to slow the rate of warming over the next couple of decades.

…nor can we ignore carbon dioxide

The next 20-30 years are also critical to our ability to address long-term climate change by bending the curve of carbon dioxide emissions as quickly as is possible. Without addressing methane and carbon dioxide emissions, we lose the opportunity to maximize the benefits of climate change efforts.

Let’s not waste time arguing about which is most important, because they both matter a great deal.   

And make no mistake: We absolutely need to remain focused on CO2 emissions reductions: A critical piece EDF’s climate agenda focuses on that goal.

Curbing methane costs 1 penny for each $4 earned

Gillis implies that reducing methane emissions could divert resources from CO2 reduction; in reality, cutting methane doesn’t have to be a costly endeavor.

A recent report by independent energy consulting firm ICF International found that 40 percent of methane emissions from the oil and gas industry can be eliminated over the next five years at a cost of less than a penny per a thousand cubic feet of produced natural gas – that’s roughly one penny spent for every $4 earned.

And these emissions reductions can be achieved by using technologies already available and on the market today. That’s an easy ask that packs a huge punch.

Let’s get to work

In the end, Gillis comes down in favor of “a two-pronged attack on climate change … far more aggressive methane control to slow global warming for the benefit of people alive today, along with aggressive CO2 control for the benefit of future generations.”

That is a sensible conclusion. Methane and CO2 are not an either-or option. It’s our ethical responsibility to do everything in our power to limit the impacts of the damaging pollution we’ve created.

To meet that obligation we need to reduce carbon dioxide and methane emissions as quickly as possible. Let’s get on with the work needed to make that a reality. 

Mounting scientific evidence underscores the crucial importance of reducing methane emissions in the U.S. The latest study, published today in the journal Science, reviewed available data from the past 20 years and found that methane emissions from the U.S. natural gas supply chain are almost two times greater than current official estimates – flagging once again that methane emissions are a serious problem. However, the Stanford-led team also concluded that the current levels of methane leakage may — in some cases — negate climate benefit of switching to natural gas. For instance, it may not be advantageous from a climate perspective to move from a diesel-powered commercial vehicle to natural gas, but benefits still exist in switching from coal to natural gas for electric power generation.  

As for what contributes to the higher than expected emissions, the study authors cited differing measurement techniques—including “bottom-up” direct measurement at the source, “top-down” readings from aircraft, and others—as well as the presence of “super-emitters” (a small number of sites or pieces of equipment producing a large share of emissions). Super-emitters are not easily sampled using most bottom-up direct measurement approaches. The team also spotlighted challenges associated with an increasingly ambiguous distinction between emissions from natural gas and oil production, both of which contribute methane to the atmosphere.

Other recent studies

This sobering assessment joins a growing list of recent studies that point to higher than expected levels of methane emissions from the oil and gas industry.

Just a few months ago, a Harvard led team published a paper in the Proceedings of National Academy of Sciences (PNAS) that found total methane emissions from all sources (e.g. livestock, landfills, oil and gas, etc.) were roughly 50 percent higher than U.S. Environmental Protection Agency estimates for the same time period, 2007 -2008.

This followed on the heels of the September 2013 PNAS paper, in which a University of Texas team looked at emissions from some activities associated with hydraulically fractured wells for the first time. The UT led bottom-up study was the first study released in EDF’s methane research series. Though it found total emissions for the production segment of the natural gas system to be similar to EPA estimates, it also found that emissions from some sources were much higher than EPA estimated – valves, compressors, and pipes located at the well pad, for example, all showed higher than estimated emissions. The study also found that emissions from well completions – at the end of the hydraulic fracturing process – were dramatically lower than EPA estimates where new emission controls were used. This is likely because in 2012, when the measurements were made, drillers were beginning to deploy the reduced emissions completions (REC) equipment required by EPA. RECs will be required for all new natural gas wells beginning in January 2015, but are not required for associated oil-and-gas wells. One clear policy implication was that REC equipment should be required across the board.

In August 2013, yet another study was released, this time by scientists with the National Oceanic and Atmospheric Administration and the University of Colorado at Boulder who are known for their expertise with top-down measurements. Published in Geophysical Research Letters, the paper reported alarmingly high levels of methane emissions from airplane readings gathered over an area of the Uintah Basin, Utah’s most active oil-and-gas region that includes production, gathering systems, processing and transmission stations.

These insights, combined with what we’re learning from the bottom-up studies highlighted in the Science paper, demonstrate that no single measurement method is sufficient to provide all the data required to understand emissions rates and sources. That’s why the diverse scientific teams EDF is working with across our 16 studies are using a wide range of techniques in tandem. (The Stanford study is not a part of EDF’s methane series, though EDF’s senior scientist Robert Harriss is a co-author.)

The Stanford paper is insightful work and we welcome the new perspectives it provides. Their survey of over 20 years of scientific literature makes an important contribution, and raises important issues about all measurement techniques in use. For example, self-selection bias may be a factor in bottom-up direct measurement studies, and top-down techniques have challenges in assigning attribution among sources. None of this takes away from the fact that these studies, despite their methodological differences, clearly indicate that methane emissions pose a serious threat to the climate. And while we work to deepen our understanding of the sources of methane emissions, there’s no question about the need for regulation to reduce these emissions.

Why methane matters

I know some are still not convinced that methane matters. A concern I hear is that reducing methane emissions is a distraction from the important work of reducing emissions of carbon dioxide (CO2). I agree that we need to remain focused on CO2 reductions, but by also reducing harmful emissions of short-lived climate pollutants such as methane, we can slow the rate of warming over the next couple of decades – something that CO2 reductions are unlikely to accomplish alone. And as I said, the threat is real. Over 40 percent of the warming experts expect to see in the next 20 years, as a result of today’s greenhouse gas emissions, will come from short-lived climate pollution that includes methane.

It is absolutely necessary for us to continue pushing as hard as we can to meet our obligation to future generations to leave a cleaner and safer world. But we also need to ensure that the shorter-term impacts of climate change – extreme weather patterns, long droughts and high temperatures seen across the country – are not intensified.

What EDF and a growing number of scientists are saying is that when it comes to emissions reductions, no one should choose between methane and carbon dioxide. It’s not an either/or scenario. Science has shown us that we need to reduce both if we want to protect the climate. We cannot afford to even consider a trade-off between current generations and future generations, which is what this comes down to. We need to protect both – and the only way to do that is to bring together our best ideas for reducing carbon dioxide AND methane emissions.

Reason for hope

There’s reason to hope that if we do this – taking the steps now to create parallel strategies to cut methane emissions from the oil and gas industry (the largest industrial source of U.S. methane emissions) and continue to cut carbon pollution from power plants – it can have a sizeable impact. And the good news is that we have affordable technologies to get started. An economic analysis in the International Energy Agency’s 2013 World Energy Outlook 2013 indicates oil and gas companies could reduce methane leaks in production fields by 50 percent at a cost of less than 1 percent of the cost of the well. This is a powerful message about the feasibility of addressing methane emissions, with an enormous upside for the climate.

The community of researchers EDF is working with will be releasing many studies over the coming year. These studies will provide ever more detailed information about sources and magnitudes of methane emissions from which it will be possible to craft ever more effective mitigation strategies. In the meantime, we need to get on with the work of reducing methane emissions and reaping the climate and air quality benefits immediately. We have everything we need to get started. And our future depends on it.

 

Duncan Hull /http://www.flickr.com/photos/dullhunk/7378166158/in/photostream/">Flickr

House Committee on Science, Space and Technology Chairman Lamar Smith recently wrote an op-ed in the Washington Post that dangerously distorted the science behind man-made global warming.

It is patently false to suggest, as Chairman Smith did, that there is a “great amount of uncertainty” regarding the fundamental science underlying our understanding of the drivers of climate change. Man-made warming has been confirmed repeatedly by the vast majority of scientific organizations including NASA, the National Academies of Science and the American Meteorological Society. A recent review also reaffirmed that 97% of peer-reviewed scientific publications that address the causes of climate change endorse the consensus that climate change is real and man-made.

Chairman Smith argues that since the U.S. decreased its greenhouse gas emissions between 2005 and 2012 we cannot be responsible for global greenhouse gas emissions. However, carbon dioxide remains in the atmosphere so long the U.S. is responsible for more of the warming we are currently experiencing than any other nation. In 2011, the United States’ emissions remained the second highest behind only China, a country with more than four times the population of the U.S. 

The U.S. continues to emit significantly more greenhouse gas per person than does any of the larger nations of the world, the few smaller exceptions are major fossil fuel producing countries. The fact that the U.S. is not currently the single largest emitter is no excuse not to lead on addressing climate change.  The logic used by Chairman Smith implies that we should only ask the very largest emitters to clean up criteria air pollution or water pollution across the U.S. If we utilized that strategy our water and air would not have seen the improvements of the past 40 years, which have reduced death rates and restored the places we cherish.

He also discusses recent findings that temperatures have not warmed significantly in the past 15 years, which is not actually the case – rather several cooler years has reduced the rate of warming, as it has several times over the past decades of rapid warming. As EDF Vice President Nat Keohane recently wrote in response to this finding, this “underscores the fundamental nature of climate change — that we are creating dangerous uncertainties” and there are various explanations for this finding, notably that an unusual amount of heat has been stored in the deep ocean, rather than at the surface.

Chairman Smith also claimed that Hurricane Sandy was not caused by climate change. Scientists, including Kevin Trenberth of the National Center for Atmospheric Research, Bob Corell from the American Meteorological Society and Jeff Masters of Weather Underground and formerly of NOAA, confirm that Sandy’s damage was increased by rising seas, warming oceans, and was consistent with scientists’ climate predictions based on a warming artic. Just as we can’t say that steroids caused any one home run by Barry Bonds, steroids sure helped him hit more and hit them farther, and now climate change is increasing the likelihood of extreme of weather events, giving us weather on steroids.

Lastly Chairman Smith says that greenhouse gas regulations would hurt our economy. He does not account for the economic costs of inaction on climate change that many studies say outweigh the cost of action. Three of the most costly weather disasters in the U.S., Hurricanes Katrina and Sandy, and the 2012 Midwest drought, have happened in the past 6 years, costing $128 billion, $62 billion and $35 billion respectively. American taxpayers are footing a large portion of this cost including $12 billion from Sandy and $16 billion from Katrina under the National Flood Insurance Program, and $11 billion in crop insurance claims from the 2012 drought. These costs will only continue to increase as the effects of climate change become more apparent.

I appreciate that Chairman Smith is writing about climate change because it is a critical national debate. As chairman of the House Science Committee, however, he should start that discussion by acknowledging the most important and sound scientific facts: Climate change is real, it is caused by pollution from human activity, and it will become increasingly expensive for the U.S. and the world.

This post first appeared on our Climate 411 blog.