Joe Romm who does important work about climate change and who runs climateprogress.org recently posted that natural gas is a bridge to nowhere. See http://www.thinkprogress.org/romm/2012/01/24/407765/natural-gas-is-a-bridge-to-nowhere-price-for-global-warming-pollution.
Let's be clear that Romm's beef with natural gas concerns carbon emissions. Romm likely would agree that, if the world switched completely from coal to gas and from oil to gas, that global mercury, lead, arsenic, smog-causing pollution, acid rain, and deadly soot all would be slashed. This hypothetical complete transition to gas would literally save every year hundreds of thousands of lives and possibly millions.
Even the air in Beijing would be safe to breathe, if China ran on gas. Fish would not be contaminated with mercury around the world, if the world ran on gas. The one-in-six women in the USA that do have elevated levels of mercury in their blood, as a result of global coal burning, would be free of mercury, if the world ran on gas.
Gas emits zero or close to zero of major pollutants that cause havoc to the world's environment and public health. It causes minor damage to water compared to the massive harm done by oil leaks and spills and coal mining. Gas is orders of magnitude less dirty than coal or oil.
But gas is not perfectly clean. It does emit carbon emissions when combusted. And Romm's beef with natural gas is about carbon emissions.
Yet, carbon emissions from coal are twice those of gas, according to a slew of studies, including the Sierra Club financed Carnegie Mellon University, Worldwatch Institute, National Energy Technology Laboratory reports as well as others. Thankfully, in his post, Romm does not cite the Howarth lifecycle gas study that has been debunked by as many as 6 other studies, including another group of Cornell University professors, all of which confirm that coal emits two times more carbon than gas on a life cycle basis.
In his Bridge To Nowhere post, Romm appropriately notes that the methane leakage rate of the natural gas industry impacts what role gas can play in solving climate change. He, in fact, says that gas could play a significant, positive role if the methane leakage rate of the gas industry was below 2% but expresses skepticism that the rate is at level.
Some research underway may shed light on whether the gas industry is or is not already at the 2% level. But if the industry is not, it can clearly get there and must. Indeed, even Professor Howarth concedes so. Howarth says in his January 2012 paper: "Can shale-gas methane emissions be reduced? Clearly yes, and proposed EPA regulations to require capture of gas at the time of well completions are an important step." Those are the words of the most extreme, anti-gas academic and his position on the current status of gas's carbon footprint is overwhelmingly rejected by an avalanche of expert studies.
The United Nations and the world's climate experts state that the world must reduce carbon emissions 50% by 2050 to stabilize heat trapping pollution at levels that would avoid truly dangerous change and risks. To achieve such reductions in effectively 39 years, all tools that can reduce emissions must be deployed and as early as possible. There is no time left to wait for a magical energy breakthrough.
Gas is ready now. It is a low-cost way to cut carbon emissions 50% today every time it displaces a kilowatt-hour of electricity generated by coal. In the US, gas is displacing coal. Coal's share of the electricity market has fallen from 52% in 2000 to 43% in 2011 and will likely be 41% by 2013. Gas's share has risen from 16% in 2000 to 25% now.
And as gas displaces coal, where are the US's fossil fuel carbon emissions? They are back to below 2000 levels, even though America today has 30 million more people and that our GDP is considerably bigger.
To be clear once more, the progress that America is making on carbon is not just because of gas. Energy efficiency as well as the boom in renewable fuels are central too.
No one tool or even three or four tools will get done the daunting job of reducing global emissions 50%. Yet the "perfectionist caucus" often stands in the way of each and every possible action in the real world of project development, for its true that some find offshore and onshore wind ugly, that wind does kill birds and bats, that six nuclear reactors have melted down in the last 35 years, that burning wood emits soot and carbon, and that gas is not perfect. No matter the inevitable attacks on anything and everything, energy efficiency, nuclear, renewables, carbon capture storage, electric vehicles, gas displacing coal and oil and much more will be needed.
Moreover, even if it were possible, switching the entire world to gas would not achieve by itself the 50% carbon reduction needed by 2050, since gas does emit carbon. But that does not mean gas has no role to play in solving the climate problem, even without carbon capture and storage technology.
Gas can cut 50% of the carbon emissions of coal and do so cheaply, lowering hugely the cost of carbon reductions, thereby making more and earlier carbon reductions economically and politically possible.
Romm himself does state that replacing existing coal generation with gas is a good thing for the climate. It literally cuts by 50% the carbon emissions from the plant. It does so today, right now, and produces electricity at a lower price than coal in the US. That is consistent with the goal of a 50% reduction of carbon by 2050.
For these reasons, it is hyperbolic to say gas is a bridge to nowhere. Nobody that I know, and I certainly am not saying that gas alone solves the climate problem. It does not. But just as clearly gas can help cool our planet.
What about the Wigley study that Romm and others cite? The study uses modeling based upon a number of assumptions and scenarios to look at climate impacts this century or the short term in climatic terms at this point. It points out that gas replacing coal reduces sulfate aerosols--a cooling forcing--and thereby perversely marginally raises temperatures for short periods. Renewables or nuclear energy replacing coal would also reduce the sulfates--the cooling forcing--and have the same effect as gas doing so.
The Wigley study assumes that gas replaces just 50% of coal. Since this is a modeling exercise, why not assume gas replaces 100% of coal? Not enough renewable energy also will do little to change global temperatures over the next 90 years. Indeed, the climate has already changed, and many scientists say a lot more warming is already baked into the climate system, even at current levels of global warming pollution.
The Wigley study assumes that 83% of the sulfur dioxide from coal is eliminated over 50 years. The reductions may well be much quicker and will be in the USA. The study's results change for the better if the reductions happen much sooner.
But most importantly the Wigley study itself, despite removing the cooling forcing of sulfate aerosols, finds in 3 of 4 scenarios that gas makes a positive contribution this century and a substantial contribution if the methane leakage rate is 2% or less. Many believe the leakage rate at least in the US is there now, and more data is on the way.
Whether the leakage rate is at 2% or not, it can and must go lower from current levels. Importantly and perhaps encouragingly, there is broad agreement that the July 2011 EPA proposed rule would reduce further methane leakage rates. The rule is vital for air quality and our climate.
Gas alone cannot solve the climate problem. That is true. Yet, the climate will not be stabilized, without gas playing a major role right now in lowering carbon pollution, until perhaps someday the world captures carbon or transitions from carbon to hydrogen.