Climate Feedback

Are the IPCC scenarios ‘unachievable’?

footprint.jpgThe dizzying economic growth in Asia threatens to disappoint expectations that new technologies will provide an easy fix for our climate problem, warn the authors of a commentary article in Nature this week.

Roger Pielke, Tom Wigley and Christopher Green believe that the Intergovernmental Panel on Change Change, which was awarded the Nobel Peace Prize last year for its work, plays “a risky game” when assuming that “spontaneous advances in technological innovation will carry out most of the burden of achieving future emissions reductions.”

Most of the emissions scenarios that the IPCC considered for its last report include significant ‘built-in’ technological change. In other words, the IPCC assumes that a good deal of climate-friendly innovation will happen spontaneously, in the absence of climate policy measures.

Now, necessity, economic growth and pursuit of profit do generate all kinds of more or less useful new technologies, from atomic bombs to iPods. But assuming that pure market forces will readily come to our aid in matters of climate change might be too optimistic, the commentary authors warn. Worse, they say, the assumption of a lot of spontaneous technological change could be misinterpreted as a license for policymakers not to take aggressive action.

Pielke, Wigley and Green have stirred up a hornets’ nest with their analysis. Some initial reactions to their call to arms are collected in an accompanying news piece. Expert opinions range from “overdue” to “totally misleading”.

So who’s right and who’s wrong, then? Are we dramatically underestimating the challenge of climate change? Or is this just one more twist exercised to unnecessarily dramatize an admittedly serious problem? Or is it all just shadow-boxing in the arcane world of scenario-making?

Economics of climate change are a politicized field. Depending on one’s standpoint (on what market forces can or cannot do, for example), one may find different answers to these questions. Less disputable is the fact that some two billion people in China and India are on the point of adapting to western living standards. Their consumptive power and increasing mobility will add to the global climate and energy problem. Let’s hope that their creativity and engineering skills will also add to its solution.

Quirin Schiermeier

Illustration: B. Mellor


  1. Report this comment

    JMS said:

    I just sat in the dark for an hour the other night praying to the earth goddess feeling superior over the un enlightened. How dare you mess with the IPCC and my feelings of moral superiority. I suggest you go sort some garbage until this TRUTH thing or what ever you call it passes.

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    Tom Fiddaman said:

    Nice commentary. It’s about time someone pointed out the emperor’s lack of clothing. I think reality may even be a little tougher.

    First, many of the models used to generate the IPCC scenarios do not assume significant depletion of conventional oil and gas. Thus they avoid the recarbonization pressure from a shift to coal, tar sands, etc.

    Second, many policymakers appear to regard technology as a substitute for market signals on greenhouse gases. Unless this changes, climate-friendly technologies will either die on the vine or see their gains realized as increases in energy service consumption rather than decreases in carbon emissions.

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    John O'Donnell said:

    We have technologies that have been in commercial deployment for 20 years with 100% reliability whose costs are dramatically dropping that can provide the backbone of the required emissions reductions: solar thermal power stations. See for the European consortium discussion, see for the Mills/Morgan paper studying US energy needs vs solar power output. 1400MW in construction or operation now, over 3000MW under contract in the US alone today. No constraints to rapid scale-up; the US built 25000 MW of power stations in under 10 yrs; these are easier to build, using only commodity steel/glass/concrete. Costs are now matching fossil fired costs. We can do it if we choose to.

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    Paul E Condon said:

    I had not been aware of how muddled is the thinking of AR4 estimate. If one actually intends to do something about atmospheric CO2, one can simplify the reasoning considerably: Disregard carbon intensity and energy intensity entirely. Instead consider the production (i.e. the mining of coal and the pumping of oil). Both production activities lead to release of CO2 into the atmosphere, excepting only for a very small amount that is captured during burning. Burning leads to the same amount of CO2 regardless of the energy or carbon intensity of the process. Improvements in these intensities will change the economic benefit of the burning, but not the size of the CO2 problem to be addressed.

    James Hansen has called for setting a target CO2 concentration of 350ppm (and more recently 320ppm). Since the concentration is now ~385ppm, extracting CO2 from the ambient atmosphere is required. The rate of the required extraction must be comparable, in order of magnitude, to the rate of the CO2 emissions, which rate can be known from world fossil fuel production. In order to actually start reducing CO2 concentration, the rate of extraction must exceed the rate of injection by some non-trivial amount.

    Atmospheric CO2 was 350ppm in 1987 and was 320ppm in 1968. The tonnage of fossil fuel that has been produced since these dates is the tonnage of CO2 that must be removed. This is a large, but not impossibly large amount. In particular, it is large enough that it will be worthwhile to try several techniques of CO2 capture concurrently and emphasize the more successful techniques in later build-out of the system.

    The size of the total build-out can be reduced by limiting the further use of fossil fuel. A balance can be struck between economic cost of limiting fossil fuel use and cost of building and operating CO2 air capture systems.

    When the target CO2 concentration has been reached, there will be a very large stock of captured carbon. If the capture has been done by growing and harvesting plants, there will be a very large stock of biofuel feed stocks. At this time all further use of fossil fuels can be stopped and replaced by biofuels. The feed stock can be replenished by continucd operation of the CO2 capture system, and the whole system made ‘sustainable’.

    I’m sure that a more detailed analysis will lead to slight corrections to this argument. I do think this argument can give a meaningful upper bound to the size of the effort.

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    Arindam Samanta said:

    The analysis by Pielke et al., points to the need for climate mitigation policies at a global level more than ever before. There are two aspects of emission reductions:

    1) Emission reduction by market driven technological advances which, in this case, largely arise from fossil fuel prices.

    2) Emission reduction by policy measures, which primarily consist of policy incentives for cleaner technology development and practices like carbon trade.

    Thus, in order to achieve a viable and healthy CO2 stabilization target of about 500 ppmv, both these major fronts need to work favorably. This means that on one hand, rising fossil fuel prices should drive the development of clean technologies. And, on the other hand, large policy incentives should also favor such developments.

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    G.R.L. Cowan said:

    My prescription: removal special consumption taxes from oil and gas, and disperse pulverized magnesium silicates in the troposphere. The energy cost of this pulverization and dispersal is small compared to the energy previously gained by putting up the CO2 the dustmotes take down. Without a special interest in continued fossil fuel burning, governments will no longer footdrag on conservation and substitutes.

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    satyam said:

    we are in from

    in weather modification technology in humidity 65 to 85 we trial

    in India which once we succeed at part of andhra pradesh , we need

    develop this technology

    this technology entirely different than any country from ground , it as

    been warm seeding g not only seed , it fertilized cloud , weather

    modification &climate control once at trial movement , technical data

    what ever u required in front of u some more data i send u thanks for

    reply , our aim is people don’t suffer from water in earth ,

    – satyam yam wrote:

    > thanx sir


    > we ready which ever our technoloy devloped we.give the demo tryal

    > which every area your choice, we hope that 100/ expeting result , we

    > waiting for reply

    indigenous technology as developing material which we use from plants &trees process for 3 years it very cheap

    taking from enverloment it no harm full

    we can trial to control globle warning climate change our mail

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    Viktoras Didziulis said:

    Sustainable development and economic growth seldom go hand-in-hand. They rather oppose each other and in most cases the winner is economic growth (money talks, trees don’t). Everyone needs energy and directly or indirectly consumes fuels in all economic activities from transportation services to software development and daily life. The only way to get the idea of “sustainable economies” working is to modify ALL nodes of existing networks of energy production, accumulation and consumption so that no part of the network is based on burning any fuels anymore. Replacing fuels with biofuels won’t help, because increasing energy consumption will inevitably cause expansion of agriculture further causing destruction of large natural ecosystems, forests, jungles that are natural sinks of carbon diokside. All this will end with impacts even higher then they are now. Oil drilling at least does not require clearing so many hectares of land as agriculture does. Another alternative – burning hydrogen – produces water, burning large amounts of hydrogen will produce large amounts of water. Water vapor is also blacklisted among the greenhouse gases. Just notice how much cloudy nights are warmer than bright ones… So are there any other possible solutions? The first (and the second, and the third, etc…) thought that comes to mind is replacing or modifying consumer systems (internal combustion engines, heaters) that require burning process, to run on something else. Well, I am an ecologist, so, engineers, please forgive me my naive assumptions, but I guess the replacement might be compressed air, liquid nitrogen, low differential stirling engines, heat pumps, yet something else… All of the above except for the “something else” are already existing technologies. Energy production and storage can be based entirely on solar, wind, geothermal energy and on existing or emerging technologies to “scavenge” energy of low temperature differences and environmental gradients (air/ground, exposed to sun/shadow, day/night, etc…). Energy could be produced and stored in forms of electricity, heat, compressed air or liquidized nitrogen. If consumer engines and other nodes of the energy accumulation-consumption network all run on electricity, compressed air or liquid nitrogen, then they in fact emit no harmful gases (in case of nitrogen you should know that it is a major compound of the air) and many problems would be gone forever. Again, excuse me for my naive assumptions,- just trying to share a little brighter vision of a “new brave world” of the future without stinks, flames, ashes and possibly (although my personal opinion is that it is already too late) without melting glaciers and submerged atoll countries. Can we manage such a transformation of technology within 50, 100, 200, 500 years? But will we be brave enough and willing to start it?

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    Jonathan Vigh said:

    Do the SRES accurately account for price sensitivity to conventional energy sources and the market-driven displacement and substitution to alternative energy sources that will occur if peak oil comes sooner rather than later? Already it seems that oil is running well ahead of cost projections from just a few years ago (although this may soon be demonstrated to be a temporary speculative ‘bubble’). What if Goldman Sach’s prediction of $200 oil comes true this year or next? There will be a very rapid push away from oil (although the push could be towards carbon intensive coal-based synfuels). I’d be curious to know how SRES accounts for peak oil – when is peak oil estimated to occur in the various scenarios? How have their economic model assumptions verified for the last few years given in the rapid runup in energy prices?

    Also, how much of a role does simple extrapolation play in the SRES, both in projections of economic activity and in development pathways? Is it possible that the global growth spurt of the 90’s and 00’s were due mainly to structural changes (i.e. fall of Communism, globalization, market reforms) that have now run their course? The U.S. adventure with novel financing (subprime mortgages, leveraging, CDOs, SIVs, etc.) may soon prove that the growth rates during this era were ultimately not sustainable.

    Is it correct to think that the rest of the undeveloped world will rapidly develop in a carbon-intensive manner like China? I think not, especially if the resource and price constraints continue emerging as they have been the past year or two. Resource limitations should place strong constraints on future global growth rates, and therefore future emissions. I’m guessing that these factors could be underestimated in the SRES. Regarding alternative development pathways, remember that many parts of Africa have experienced the telecommunications boom in the past decade, but instead of following the traditional pathway followed in the more developed nations (landlines), they leapfrogged straight to wireless. As new energy alternative technologies come online, newly developing nations may skip the carbon-intensive devlopment patterns entirely and go straight to more cost effective technologies. How much of this is accounted for in the SRES?

    I’d guess that the SRES has a) overestimated global economic growth rates and b) assumed too much business as usual in regards to development pathways. I haven’t studied the SRES in depth (maybe they already account for everything I’ve mentioned), but I hope the new scenarios will account for these economic feedbacks in a robust way.

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