Fracking and global warming
Ginny - Now, Bob Howarth from Cornell University has been studying the methane emissions from fracking. Hi there, Bob.
Bob - Hello. How are you?
Ginny - I'm alright, thanks. So, why is methane such bad news for the environment?
Bob - Well, methane is the second largest contributor to global warming after carbon dioxide at the present and it's equivalent in terms of its current role in warming the planet, it's equivalent to about almost 40% of what carbon dioxide is doing. So, it's a major threat and the critical thing to realise is that climate system responds in different timescales to carbon dioxide and to methane. The response to methane is much shorter, which means that over the next 2 decades, any methane that is released is very damaging to the climate. The most recent models for instance show where it warms the surface of the earth on average by 7/10 of a degree over the last 40 years or so, we're on target to up to 1 ½ degrees, doubling that within the next 15 years and going to 2 degrees within 35 years or so from now. And those sort of temperatures are very potentially dangerous, we have the potential to hit a tipping point in the climate system and get into runaway global warming. If we want to avoid that, clearly, we need to reduce carbon dioxide emissions, but the methane emissions are even more critical. The only way to avoid those dangerous tipping point temperature changes at this point in time, given the carbon dioxide we've already released is to start immediately to reduce methane. If we look at where methane is coming from, it's coming from many sources, but the natural gas industry is one of the top two in the world. It's the number one here in the United States. So, we need to wean ourselves from natural gas, even more quickly than other fossil fuels. It's the most dangerous fossil fuel at this point in time, given where we are with climate change.
Ginny - So, how likely is it that some of this gas will actually escape during the fracking process?
Bob - Well, it's definitely escaping. We published a paper on this back in the spring of 2011 which is the first published analysis on how methane leakage might contribute to the greenhouse gas of shale gas. We said it could be in the neighbourhood of 3% up to perhaps 8% of the light farm production of a well. It's emitted either at the time of fracturing or if the gas is used, transmitted to final consumers. The data behind that were not well-documented. We used the best available data, but they were not well-documented data. But what has happened is that we spurned a lot of interest and there's been a lot of scientific groups about measuring things now. The most recent studies are now 4 or 5 published studies, showing that in these shale gas and tight sand fibre frack fields that the emission level seem to be more in the 6 to 9, maybe 12%. So, there's a huge amount of methane that's leaking from these fields as it's currently being produced in the United States.
Ginny - So, we've been talking about how economically important gas is. If so much of it is escaping, wouldn't the companies want to somehow capture that so that they weren't losing 12% of their profit?
Bob - Well, it's not 12% of their profits because as they're doing a cost-benefit analysis. They could be more stringent in the technologies they're using, but they need to invest money and they need to invest more time in willing to do that. They have made a decision to drill more wells more quickly and use technology which is not as tight, if you will, to the emissions. It's an economic decision and it's clearly decision they've made. Could we regulate that to reduce the emissions? The answer is, yes. To date in the United States, we haven't been very effective at doing that, but gases are inherently slippery. They easily leak. It's very, very difficult to get every little last bit. Methane leakage at a rate of even 1% or 2% is damaging from a standpoint of climate change, quick damaging. I don't think we can possibly get down there even with the best available technology.
Ginny - So, we've got a comment that's come in here from Jo from Cambridge who says that he hears that people who live in the US fracking zones can set fire to the water that comes through their taps. How is that possible?
Bob - There is indeed evidence of that, just south of where I live, about 60 miles, you're under the Pennsylvania Marcellus Field and there's a very strong research coming out of Duke University that's shown that if you live within about a kilometre of a gas fracking operation, you have a much higher probability of having elevated level of methane in your drinking water. Well, it's high enough that indeed it is flammable. The reason for that is still subject to some debate but my colleague here at Cornell, Tony Ingraffea who's the engineer who's been working on fracking technologies since the 1970s. Tony has combed over the records for the state of Pennsylvania and what he finds is that at least 6% and perhaps as much as 30% of the fracked wells in Pennsylvania have problems with how they were drilled, how the cement casing was put in within the first year. So, there's clearly a mechanism for this gas to leak out and get into the aquifers and clearly, some of that gas is getting out.