A must-read new study by climatologist Ken Caldeira and tech guru Nathan Myhrvold (!) makes clear the world’s only plausible hope to avert catastrophic temperature rise this century is aggressive deployment of zero-carbon technologies and conservation.
The Institute of Physics news release explains:
… technologies that offer only modest reductions in greenhouse gases, such as the use of natural gas and perhaps carbon capture and storage, cannot substantially reduce climate risk in the next 100 years.Delaying the rollout of the technologies is not an option however; the risks of environmental harm will be much greater in the second half of the century and beyond if we continue to rely on coal-based technologies.
Those are the bombshell conclusions from “Greenhouse gases, climate change and the transition from coal to low-carbon electricity,” in IOP Publishing’s journal Environmental Research Letters.
Many decades may pass before a transition from coal-based electricity to alternative generation technologies yields substantial temperature benefits. Panels above show the temperature increases predicted to occur during a 40-yr transition of 1 TWe of generating capacity. Warming resulting from continued coal use with no alternative technology sets an upper bound (solid black lines), and the temperature increase predicted to occur even if coal were replaced by idealized conservation with zero CO2 emissions (dashed lines) represents a lower bound. The colored bands represent the range of warming outcomes spanned by high and low life-cycle estimates for the energy technologies illustrated: (A) natural gas, (B) coal with carbon capture and storage, (C) hydroelectric, (D) solar thermal, (E) nuclear, (F) solar photovoltaic and (G) wind.
These results are not entirely news to people who follow the recent climate and energy literature, which I’ve written about at length — see “NCAR Study: Switching From Coal to Gas Increases Warming for Decades, Has Minimal Benefit Even in 2100.” The fact that natural gas is a bridge fuel to nowhere was first shown by the International Energy Agency in its big June report on gas — see IEA’s “Golden Age of Gas Scenario” Leads to More Than 6°F Warming and Out-of-Control Climate Change.
But what’s new is the first peer-reviewed analysis that “has predicted the climate effects of energy system transitions” with “a quantitative model … that includes life-cycle emissions and the central physics of greenhouse warming.”
What’s also remarkable about this study is the lead author, Nathan Myhrvold. You may recall Myhrvold, the former CTO of Microsoft, from his anti-clean-energy and pro-geoengineering quotes in”Error-riddled book Superfreakonomics,” which I and many, many others debunked at length in 2009.
Myhrvold was quoted back then about the “carbon debt” of the clean energy build-out: “Eventually, we have a great carbon-free energy infrastructure but only after making emissions and global warming worse every year until we’re done building out the solar plants, which could take 30 to 50 years.“
Caldeira loves to do actual analyses of such hand-waving claims. What he and Caldeira show here is that in fact replacing coal with clean energy starts getting you off the warming path within two decades and sharply off within four decades. But not natural gas.
Myhrvold explained to Climate Central:
The bottom line that emerges from this “life-cycle analysis,” or LCA, said Myhrvold, is that by the time we could switch from coal to gas, there would already be so much more CO2 and methane in the atmosphere that we’d be much deeper in the hole. “It’s like living on a credit card,” he said. “It’s easy to get into a situation where it will take years and years to pay back.”
In fact, he argues, because CO2 stays in the atmosphere for so long once it’s up there, a switch to natural gas would have zero effect on global temperatures by the year 2100. “If you take 40 years to switch over entirely to natural gas,” he said, “you won’t see any substantial decrease in global temperatures for up to 250 years. There’s almost no climate value in doing it.”
It should be obvious that if you are just building new gas plants and not replacing coal power 1 for 1 — which is what we are doing today — then things are even worse for gas. And this doesn’t even count the opportunity cost of all that money spent on gas infrastructure.
UDPATE: Myhrvold explained to me in an email that “We only model ‘conventional’ gas, because we did not have good LCA [life-cycle analysis] studies for shale gas from fracking. However since our paper was accepted several have come out. This area is still controversial but people are coming in with higher emissions from shale gas than conventional gas. That would tend to make any shale gas scenarios worse than the natural gas scenarios we cover.
Much of the media coverage of this study has been of the form, “Low-carbon technologies ‘no quick-fix,’ say researchers,” which is understandable since that was the headline of the IOP news release. But anyone who thought that even aggressive action today could substantially change our warming path before, say, 2040, wasn’t paying close attention to the literature (or reading Climate Progress).
Yes, replacing the energy infrastructure can’t be done instantaneously, CO2 lasts a long time in the atmosphere, we have a fair amount of warming in the pipeline, and the “ocean thermal inertia delays the climate benefits of emissions reductions,” as the study notes.
The climate fight is about the post-2040 world. If we act aggressively now, we can keep global warming close to 3.6°F (2C). But if we delay we face the real prospect of 7–9°F (4–5C) global warming in the second half of the century, with substantially higher warming over most of the United States. That is “incompatible with organized global community, is likely to be beyond ‘adaptation’, is devastating to the majority of ecosystems & has a high probability of not being stable (i.e. 4°C [7F] would be an interim temperature on the way to a much higher equilibrium level),” according to Professor Kevin Anderson, director of the Tyndall Centre for Climate Change in Britain (see here).
That’s why the authors conclude that if you want to get “substantial reductions in temperatures relative to the coal-based system” you need to act now to shut down coal plants and replace them with very-low-carbon systems or conservation:
Despite the lengthy time lags involved, delaying rollouts of low-carbon-emission energy technologies risks even greater environmental harm in the second half of this century and beyond….
Technologies that offer only modest reductions in emissions, such as natural gas and — if the highest estimates from the life-cycle analyses are correct — carbon capture storage, cannot yield substantial temperature reductions this century. Achieving substantial reductions in temperatures relative to the coal-based system will take the better part of a century, and will depend on rapid and massive deployment of some mix of conservation, wind, solar, and nuclear, and possibly carbon capture and storage.
And this was a surprise to the lead author:
“The most surprising thing we found,” lead author Nathan Myhrvold told me recently, “is that unless you switch to a form of energy that cuts emissions really drastically” — and he isn’t talking about any piddling 50%, either — “you basically don’t get any real effect.”
Interestingly, methane leakage doesn’t seem to play a major role in these findings — even though recent research suggests it may be substantial (see Study: High Methane Emissions Measured Over Gas Field “May Offset Climate Benefits of Natural Gas”).
What is fascinating, if I am reading supplemental chart S2 correctly, is that there is substantially more radiative forcing from the waste heat in a natural gas plant then from methane leakage in the whole life-cycle of natural gas power.
If, like me, you thought waste heat was not a big factor, you were half right. It isn’t a big factor for coal per se, but when you are trying to replace coal, it turns out to have a moderate impact in the lifecycle analysis of some alternatives (like gas), which matters when you are doing this kind of mass energy transition.
As an aside, I have to comment on a new post by NY Times blogger Andy Revkin, “A Fresh Scientific Defense of the Merits of Moving from Coal to Shale Gas.” Revkin, who doesn’t mention this new peer-reviewed whole-energy-system study, cites a press release (!) to conclude, “But, again, the notion that gas holds no advantage over coal, in weighing the climate implications of energy choices, is fading fast (to my reading of the science and that of many others).”
The notion that “gas holds no advantage over coal in weighing the climate implications of energy choices” is a semantic red herring. We now have 2 major unrebutted peer-reviewed scientific studies that make clear that if your goal is to substantially alter the projected temperature rise on our current emissions path, natural gas isn’t your answer. Indeed, it is a massive diversion of resources that need to go to “rapid and massive deployment of some mix of conservation, wind, solar, and nuclear, and possibly carbon capture and storage.”
And I repeat, if, as is the case today, natural gas isn’t replacing coal 1 for 1, it is even worse.
BOTTOM LINE: If you want to have a serious chance at averting catastrophic global warming, then we need to start phasing out all fossil fuels as soon as possible. Natural gas isn’t a bridge fuel from a climate perspective. Carbon-free power is the bridge fuel until we can figure out how to go carbon negative on a large scale by the end of the century.
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