Gas or coal? The quandary, the indecision!

coal protest

It’s hard to know what to say about Tom Wigley’s new paper on the climatic repercussions of replacing coal with natural gas: he says gas and coal are both good, and they’re both bad, but the truly remarkable thing is that, where for years the greens have been telling us to hate coal and everyone who uses it, now it’s hard to choose between coal and gas.

It doesn’t matter whether you believe mankind is warming the planet dangerously or not, Wigley tells us that it makes hardly any difference to the warming whether you use gas or coal. So why switch to gas? There’s no advantage in it.

In 150 years the advantage of gas in reducing global temperature would have grown to about 0.2°C — still minuscule; in the environment, undetectable — and even that change will be purchased at huge expense.

It slashes the greens’ arguments to ribbons. We need no longer listen as they praise natural gas and excoriate coal for its dangerously warming emissions, because the difference between them is indistinguishable — staying with coal makes the world by 2050 only 0.02°C warmer. If we make the expensive change to gas, after one hundred years, it’s still only 0.1°C cooler than coal. Completely undetectable.

(Those figures are approximate, derived by running a ruler over Wigley’s graph of the net effect of a 5% leakage of methane. Try it yourself here — link further down.)

coal to gas influence on global temp

The global warming effects of the two methods of obtaining energy are very similar. There are more real pollutants from coal, so we need modern installations to keep the air clean, but we don’t need to quit coal with the religious zeal of the greens. Or the expense or the haste.

In fact, Hansen can go hang; his “coal trains of death” are the exaggerated product of an imagination gone beyond reality.

coal protest

The paper, Coal to gas: the influence of methane leakage, published in August in Climatic Change Letters, re-examines the effects of changing from coal to natural gas to produce energy.

It’s been done before by Hayhoe et al. (2002) but since then we’ve invented fracking to get at the gas in shale beds. Fracking will tend to allow a little more methane leakage than conventional gas production. The scientists wanted to investigate that because of the relatively enormous global warming potential (GWP) of methane over carbon dioxide.

The GWP of methane is a matter of some dispute elsewhere on this blog.

The paper uses models more than measurements and of necessity makes assumptions about the future so there must be sizeable uncertainties but there is an interesting discussion at the end (emphasis added).

In our analyses, the temperature differences between the baseline and coal-to-gas scenarios are small (less than 0.1°C) out to at least 2100. The most important result, however, in accord with the above authors, is that, unless leakage rates for new methane can be kept below 2%, substituting gas for coal is not an effective means for reducing the magnitude of future climate change. This is contrary to claims such as that by Ridley (2011) who states (p. 5), with regard to the exploitation of shale gas, that it will “accelerate the decarbonisation of the world economy”. The key point here is that it is not decarbonisation per se that is the goal, but the attendant reduction of climate change. Indeed, the shorter-term effects are in the opposite direction. Given the small climate differences between the baseline and the coal-to-gas scenarios, decisions regarding further exploitation of gas reserves should be based on resource availability (both gas and water), the economics of extraction, and environmental impacts unrelated to climate change.

What a turnaround.

I expect the Hockey Team will turn on Professor Wigley with a vengeance, and I don’t expect Greenpeace to endorse the study quickly.

PS: I’ve just refreshed my memory of Prof Wigley’s track record. Is this story the more remarkable because of his history of ultra-warmism? Do these findings change your perception of him?

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4 Thoughts on “Gas or coal? The quandary, the indecision!

  1. Andy on 24/09/2011 at 8:01 pm said:

    Shale gas is an interesting one. Recent data from the UK suggests that they have enough shale gas deposits for at least the next 100 years.

    My understanding was that gas was relatively low co2 emissions compared to coal.

    However, this seems of little concern to those of the warmist creed, whose only True Path is to sacrifice the land to Gaia with their bird-chopping eco-crucifixes.

  2. Nick on 24/09/2011 at 11:22 pm said:

    Did you read the wikipedia entry on shale gas? It’s worth a look

  3. Doug Proctor on 25/09/2011 at 5:36 am said:

    The non-impact of their proposed, unilateral regulation and fossil fuel reduction/switch is beginning to hit them. Only a radical few are prepared to de-industrialize the world, are prepared to accept a global government with coersive powers over member nations for CO2 reduction purposes. Only a radical few are willing to crush their own economies, emfebble their own nations, bring energy-poverty to their own families and friends, just to show their moral heart.

    The ineffectiveness of fossil fuel attacks must make many despair, but also come to grips with the distance between what they thought they could accomplish and what they can accomplish, and with the true cost and true benefit of their dreams. Which creates more of a splash of cold water in the face than anything.

  4. Australis on 25/09/2011 at 3:00 pm said:

    The biggest aspect of the Wigley paper is that he says a switch from coal power to wind or solar will also speed up climate change during the next 40-50 years!

    Although the MSM have carefully focussed on the contribution to AGW from fugitive methane, Wigley’s main effect arises from the loss of cooling aerosols when a coal plant is closed.

    This means that shifting from coal to windmills will bring on warming, sea level rise, malaria, extreme weather, etc for the next two generations.

    In response to an inquiry from Steve Macintyre, Tom Wigley said he had included the problem in a paper he published in 1991.

    If it wasn’t for China, we’d all be doomed!

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