GUY RAZ, HOST:
It's WEEKENDS on ALL THINGS CONSIDERED from NPR News. I'm Guy Raz.
This past week, the National Oceanic and Atmospheric Administration, or NOAA, released a report linking climate change to some of the extreme weather events of 2011, things like the devastating drought in Texas and record high temperatures in Britain.
Now, none of this bodes well for the future, but there is a possible glimmer of hope. It turns out that U.S. carbon emissions are down nearly 8 percent since 2006. Now, much of that has to do with a weak economy - people are consuming less electricity.
But another part could be related to the decline of coal and the rise of cleaner-burning natural gas. Yesterday on the program, we heard about how natural gas is killing the Appalachian coal industry. Today for our cover story, we're going to take a closer look at its impact on the environment, both the good and the bad.
DAVID VICTOR: The shift from coal to natural gas has reduced U.S. emissions of carbon dioxide by 400 to 500 million tons of carbon dioxide per year. And to put that number in perspective, that number is on the order of twice the total effect of the Kyoto Protocol in the rest of the world.
RAZ: That's UC San Diego professor David Victor. He's an expert on the politics of fossil fuels. We'll hear more from him in a moment, but first to that NOAA report we just mentioned.
Philip Mote was one of its authors. He is the director of climate change research at Oregon State University. He and a team looked at last year's drought in Texas, and they compared what happened there with climate models going back five decades. And they wanted to figure out the odds that the drought was indeed related to climate change.
PHILIP MOTE: It was so far beyond anything that had happened before. It was so much warmer a summer than the next warmest summer, and so much drier, it really was a very extreme event.
RAZ: Should we expect more extreme weather events in the coming years?
MOTE: Well, I think that's a question that science is still answering, but certain types of extreme weather events, it's pretty clear, are increasing and will increase as the climate changes. Extreme heat events being one; in some places, extreme rainfall events. Extreme cold events, there's very little reason to believe those will get more common.
One incorrect conclusion is that global warming is not happening. Another incorrect conclusion is that global warming is making our weather more extreme in every respect. The correct conclusion is probably that that cold event happened despite global warming.
RAZ: What ultimately do you think this report by NOAA that you are a part of - what should we get out of it? I mean, do you want readers to say, well, we need to be prepared for this, or we need to begin to seriously think about carbon emissions, greenhouse gas emissions? What's the hope behind it?
MOTE: Well, I think for the scientists involved, the primary interest really is, can we understand what's happening in the world around us? That's always the motivation of science. In this case, we're talking about events that are part of a larger landscape of how we're changing the climate.
There are certainly preparedness issues. Even without climate change, in some respects, the ever-growing human race is very unprepared for extreme events. But we should certainly be prepared for those events that we now think are extremely unlikely, and they're actually getting much more likely.
RAZ: That's Philip Mote, one of the authors of the new report by NOAA linking climate change to extreme weather events. The question now is whether human behavior can halt the pace of climate change. President Obama has set a goal of reducing U.S. greenhouse gas emissions by 17 percent by the end of the decade.
And a new study suggests that goal may actually be feasible, not because of tough new regulations or legislation, but rather because of the increasing use of natural gas to generate electricity. Gas is now one of the cheapest sources of electricity generation - half the price of coal.
Much of this is a recent development, the result of advances in hydraulic fracturing or fracking, that controversial process by which gas is extracted from deep under rock formations. Fracking now produces a third of all U.S. natural gas.
Lawrence Cathles, a professor at Cornell University who wrote that study, took a close look at natural gas usage, and he found that replacing coal with natural gas would cut about 40 percent of carbon emissions linked to global warming.
LAWRENCE CATHLES: When you burn natural gas, it's a cleaner-burning fuel. It combusts in part to water rather than just CO2. And so there's intrinsically 30 or 40 percent less CO2 produced when you just burn natural gas as opposed to, say, for example, coal. But the more significant thing for natural gas if you use it for electricity generation is natural gas can generate electricity with almost twice the efficiency in terms of conversion of the energy content of the fuel that you actually get converted to electricity. You convert twice as much as you do with coal, more or less.
RAZ: Now, natural gas is made up largely of methane. That is a greenhouse gas. Doesn't fracking - hydraulic fracturing - doesn't the process, you know, by which natural gas is extracted from the earth, doesn't that lead to leaks and higher emissions?
CATHLES: I don't think so, no. Natural gas in areas where you're burying organic material is leaking out all over the place. It's more or less ubiquitous in areas where you're burying carbon. We're burying carbon all the time anyway as we bury plant material and whatnot.
RAZ: How is that it wouldn't leak into the atmosphere when you fracture these rocks and you extract this gas? I mean, it would seem self-evident that it would leak.
CATHLES: Some does, and the question is how much. And the numbers for the leakage of gas from the well site to the customer through the pipes and compressors and so on and so forth is about one and a half percent of the total production of the gas. So we are losing a bit of gas in bringing it to the customer, but it's not significant from a climate point of view.
RAZ: You argue even with that methane that's released into the atmosphere, if natural gas replaces coal, U.S. carbon emissions will be reduced by 40 percent.
CATHLES: In the short term, in the period over which you make this transition, if the leakage is about one and a half percent or 2 percent or even 3 percent, which, I think, is way too high, the U.S. will decrease its greenhouse gas emissions by, you know, something up to 40 percent depending upon exactly how much leakage there is.
RAZ: The argument you often hear is, well, coal is bad for the air and the atmosphere and - but natural gas, fracking, is a disaster for water supplies.
CATHLES: No, I don't think so there either. I think what's happening is people don't like the idea of natural gas being tapped in their backyard, and there's methane in water in a lot of these areas today. I'm quite sure I could've lit my faucet on fire, and this is where I live. We moved out of that house.
RAZ: This is in upstate New York we're talking about.
CATHLES: It's in upstate New York, yeah.
RAZ: But why would you want to drink that water?
CATHLES: Methane, you can't smell, you can't taste, you really don't even know it's there. It's not harmful to you unless you, you know, in a shower accumulate enough of it that it becomes an explosion hazard.
RAZ: But is it worth it? Is that risk, in your view, worth it? I mean, essentially what you're saying is there is evidence that suggests that fracking can damage water or actually...
CATHLES: I don't think there is, no. I disagree with that. I think that the risk from a methane escape point of view is in the shallow part of the drilling before you've got the casing in place properly. And the risk is tapping out one of these shallow gas pockets that you would tap out if you drilled a water well, for example. And we can get 40 percent of the way we - distance we need to by accepting the new availability of natural gas, and I think it makes just good sense to do it.
RAZ: That's Lawrence Cathles from Cornell University. But even with the reduction in U.S. carbon emissions in recent years, is it enough to slow down climate change? And are the potential environmental costs of fracking worth it? On that question, says David Victor, a fossil fuel expert at UC San Diego, the jury is still out.
VICTOR: While there's been a big reduction in U.S. emissions of carbon dioxide because of this shift to natural gas, it hasn't led to the kind of reductions that you need to stop global warming, which is a 50 percent to 80 percent reduction. So natural gas at best is a bridge to some kind of future where we have even lower emissions. But it's better to have a bridge than nothing.
RAZ: This gas revolution, you have also argued, is not all roses. We're talking about some potentially serious consequences.
VICTOR: Yeah. I think we need to watch out for the environmental side effects of the gas revolution. There have been some wells that have led to small earthquakes. I'm frankly much more concerned about the local water pollution from fracking operations. And if the best practices aren't used in the well, then some of that water could leak into the groundwater, be spilled on the surface and so on.
There are air pollution concerns associated with fracking as well, and so we need to find ways to address those. And I guess it's important to underscore that we don't right now know whether shale gas itself produces other kinds of emissions. So some people are worried that the process of fracking and producing gas and moving it around the country might cause leakage of methane. So, that could offset some or maybe all of the benefits of natural gas.
I think the best science in this area doesn't find that to be a big problem, but we need to keep monitoring natural gas production methods to make sure that we aren't accidentally making the problem worse by shifting to fracking and natural gas.
RAZ: Does it also take our eye off renewables? I mean, does it - if we're so focused on cheap natural gas, what does that mean for wind power, for solar power?
VICTOR: Well, I think the initial impact for wind and solar - wind much more than solar because wind is the largest share of renewable energy and is the part of renewable energy that's most competitive right now. The biggest impact on wind is to make wind less competitive because wind is now competing against alternative sources of electricity that are much less expensive than they were a decade ago.
I think the wind industry needs to also learn how to compete toe to toe with its rivals without federal subsidies and without mandates. And so I suspect that over the long haul, this is going to result in a renewable power industry that's more competitive, and that's good news.
It's one thing to spend a lot of money on supporting renewable energy as a new technology. But now that it's scaling up, that technology has to grow up as well and be able to compete. Cheap natural gas is a formidable competitor, and I hope it leads to a more competitive wind and solar industry.
RAZ: That's UCSD's David Victor. For now, natural gas is on a rapid ascent. Last month for the first time in U.S. history, gas generated as much electricity as coal, now one-third of all our power.