Posted by: JohnnyRook | December 18, 2008

Coal IS the Enemy, But There May Be a Lot Less of It Than We Think

James Hansen has been saying for a while that we will inevitably use up all our oil, and that what we really need to be worried about is our coal use, which he says must cease by 2030 if we are to avoid catastrophe. Dr. Hansen is justly famous for his accurate predictions regarding global warming. Jeff Goodell writes of him:

Maybe Justin Timberlake or Barry Manilow draws a more adoring crowd, but I doubt it. Hansen is not just a rock start here at AGU, [American Geophysical Union] but the one true prophet, the Man Who Saw It All Before Anyone Else.

We Must Stop Using Coal

Thus, it should come as no surprise that new research confirms his position on the coal question.

New climate change scenarios quantify the idea that oil is only a small component of the total global warming problem — the real problem is coal.

If the world replaced all of its oil usage with carbon-neutral energy sources, ecologist Kenneth Caldeira of Stanford University calculated that it would only buy us about 10 years before coal emissions warmed the planet to what many scientists consider dangerous levels.

“There’s an order of magnitude more coal than oil. So, whether there is a little more oil or a little less oil will change the details in, say, when we reach two degrees warming, but it doesn’t change the overall picture,” Caldeira said Wednesday at the American Geophysical Union annual meeting.

Many of the efforts to “green” our world’s infrastructure have focused on the importance of changing the world’s transportation systems. Indeed, one of the images of environmental destruction is the car-choked freeways of Los Angeles — and hybrid vehicles like the Toyota Prius have become a badge of environmental pride.

But as the latest projections show, when it comes to global warming, oil is a bit player on a stage dominated by the massive amounts of coal burning, particularly in the United States and China.

“If we want to change the overall shape of the global warming curve and instead of having it go up, stabilize and eventually go down, we need to deal with coal,” Caldeira said.

The BBC reports that Dr. Caldeira’s view is

… shared by Pushker Kharecha from Nasa’s Goddard Institute for Space Studies (Giss).

“We cannot move into things like coal-to-liquids and unconventional fossil fuels such as methane hydrates, tar sands, oil shale and so forth,” he said.

“If they become large-scale substitutes for oil and gas, that would worsen things because they are much dirtier than oil and gas because they produce more emissions per unit energy delivered.”

Dr. Kharecha, as Al Gore did recently, also endorsed Dr. Hansen’s goal of a target of 350ppm of CO2 (currently we are at 387ppm).

Dr Kharecha presented details of recent research from the US, UK and France looking at the feasibility of not only constraining the growth of CO2 emissions but actually reducing its concentration in the atmosphere to 350 parts per million by volume (it is currently up at about 385ppmv).

The group found it was possible, but only with a prompt moratorium on new coal use that does not capture CO2, and a phase out of existing coal emissions by 2030.

Reforestation together with improved agricultural practices could help draw down CO2.

“Efficiency and conservation have huge potential to offset emissions in the near term,” Dr Kharecha told BBC News.

“And then in the mid-term and long-term we can focus on moving to alternatives such as renewable energies, and possibly a balanced look at nuclear because it does provide many benefits in addition to the numerous problems that it poses.”

How Much Coal Do We Really Have?

Another paper presented at the AGU meeting suggests that the eventual damage from coal may be less than previously thought for the simple reason that there may be less coal than previously estimated. Jeff Goodell has detailed in his book Big Coal: The Dirty Secret Behind America’s Energy Future (pp 12-15) how estimates of recoverable American coal have fallen from over 2 trillion tons in 1909 to 243 billion tons in 1974. More recent research indicates that the reality may actually be a mere fraction of that 1974 figure.

Now, Dave Rutledge, chair of Caltech’s engineering and applied sciences division is arguing that world coal supplies are far less than previously estimated.

A new calculation of the world’s coal reserves is much lower than previous estimates. If validated, the new info could have a massive impact on the fate of the planet’s climate.

That’s because coal is responsible for most of the CO2 emissions that drive climate change. If there were actually less coal available for burning, climate modelers would have to rethink their estimates of the level of emissions that humans will produce.

The new model… suggests that humans will only pull up a total — including all past mining — of 662 billion tons of coal out of the Earth. The best previous estimate, from the World Energy Council, says that the world has almost 850 billion tons of coal still left to be mined.

“Every estimate of the ultimate coal resource has been larger,” said ecologist Ken Caldeira of Stanford University, who was not involved with the new study. “But if there’s much less coal than we think, that’s good news for climate.”

Rutledge argues that governments are terrible at estimating their own fossil fuel reserves. He developed his new model by looking back at historical examples of fossil fuel exhaustion. For example, British coal production fell precipitously form its 1913 peak. American oil production famously peaked in 1970, as controversially predicted by King Hubbert. Both countries had heartily overestimated their reserves.

It was from manipulating the data from the previous peaks that Rutledge developed his new model, based on fitting curves to the cumulative production of a region. He says that they provide much more stable estimates than other techniques and are much more accurate than those made by individual countries.

“The record of geological estimates made by governments for their fossil fuel estimates is really horrible,” Rutledge said during a press conference at the American Geological Union annual meeting. “And the estimates tend to be quite high. They over-predict future coal production.”

You can find more detailed information including video and a power point presentation with lots of charts and graphs here on Professor Rutledge’s home page.

With Rutledge’s new numbers, the world could burn all the coal (and other fossil fuels) it can get to, and the atmospheric concentration of CO2 would only end up around 460 parts per million, which is predicted to cause a 2-degree-Celsius rise in global temperatures.

For many scientists, that’s too much warming. A growing coalition is calling for limiting the CO2 in the atmosphere to 350 parts per million, down from the 380 ppm of today, but it’s a far cry from some of the more devastating scenarios devised by the Intergovernmental Panel on Climate Change.

“Coal emissions really need to be phased out proactively — we can’t just wait for them to run out — by the year 2030,” said Pushker Kharecha, a scientist at NASA’s Goddard Institute for Space Studies. “There is more than enough coal to keep CO2 well above 350 ppm well beyond this century.”

The urgency of ceasing to use coal is even greater than Kharecha describes. Even if Rutledge is correct and we could burn all our coal and still only have CO2 levels of 460ppm, those levels are high enough to produce rapid sea level rise that would continue for centuries.

More than that, the 460ppm being discussed here is probably based simply on the burning of the coal itself. Yet some climate scientists think that if we reach 460ppm there will be no way to stop there. Feedbacks from reduced albedo due to ice melt and changes in vegetation patterns and methane release from permafrost, peat bogs and the ocean bottom could be enough to push us to 720 or a 1000ppm from which there would be no salvation on any time scale meaningful to human beings.

Related post:

Dr. James Hansen: <a href=”“>”How do we make them understand how serious this is?”

Crossposted at Daily Kos



  1. Winston Churchill said:
    “You can always count on Americans to do the right thing – after they’ve tried everything else.”

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