Human footprint in Antarctic warming

This new research comes to no surprise – but for those who are still skeptical it provides another evidence that we humans are changing our global climate to an extent that is not advisable. MW

The rise in Arctic and Antarctic temperatures in recent decades can be attributed directly to human activities, according to a new study online in Nature Geoscience. Patterns of temperature change in Antarctica are much less clear than the Arctic warming signal; however, the authors show that temperature is rising in those regions of Antarctica where data is available and that this warming is caused by human-induced emissions of greenhouse gases and other pollutants.

Nathan Gillett and colleagues compiled records of air temperature across the Arctic and Antarctic regions since 1900. They then compared the observed temperature patterns with those produced by numerical simulations with and without emissions from human activities. The team finds that only the models that included human influences, such as emissions of carbon dioxide and chlorofluorocarbons, are able to reproduce the observed temperature trends. This model-observation comparison enables the group to conclude that human activities are causing warming at both poles.

In an accompanying News and Views article, Andrew Monaghan writes that: “Their work demonstrates convincingly what previous studies have suggested – that humans have indeed contributed to warming in both the Arctic and Antarctic regions.”

Source: Nature Geoscience

Desertec: Der Traum vom Wüstenstrom

Ein neuer Markt zieht immer Abenteurer, Goldwäscher und Phantasten an. Und so verwundert es nicht, wenn auch im Feld der erneuerbaren Energien immer wieder Geschichte an die Oberfläche sprudeln, die so klingen, als seien sie frech aus einem Jules-Verne-Roman herauskopiert. Eine solche Geschichte ist das Projekt Desertec: der kühne Traum nämlich, "grünen" Strom über tausende von Kilometern hinweg vom mittleren Osten und Nordafrika nach Europa zu transportieren.

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Trip Report from Dr. James Hansen

This report describes the insights of the American climatologist James Hansen from his trips to England, Germany, and Japan where he called for a moratorium on coal-fired power plants – unfortunately without success.

Germany

My “Dear Chancellor” letter was translated to German and about to be published in a German paper, but, upon advice of John Schellnhuber, science adviser to the German government, I removed the letter from my web site and withheld it from publication in Germany, instead accepting an invitation to speak with the Minister of the Environment, Sigmar Gabriel. That meeting occurred in June, with Schellnhuber and Stefan Rahmstorf in attendance.

I am grateful for Minister Gabriel’s generosity with his time, and I have no doubt about his sincerity in dealing with climate change. However, we did not come to a common understanding about the implications of geophysical boundary conditions on fossil fuels. The stark policy implication of the data, I assert, is urgency for a moratorium on coal-fired power plants.

Recognition of these boundary conditions is of paramount importance. The Kyoto Protocol was doomed to failure because fossil fuel boundary conditions were not appreciated (see “Japan” below). Post-Kyoto approaches presently being considered are doomed for the same reason.

 

Fig. 1. (a) carbon sources, and (b) CO2 scenarios if coal emissions are phased out linearly over 2010-2030 period; return below 350 ppm can be hastened via reforestation and carbon sequestration in soil, and further via capture of CO2 at gas-fired power plants. For details see References 1 and 2.

In the discussion with Minister Gabriel, I returned several times to Fig. 1. We did not disagree about anything in that chart per se. Purple areas in Fig. 1a are emissions to date; reserves (blue) are uncertain. Expert opinion suggests that we are now close to “peak oil”, i.e., remaining oil is about as much as has been used already. Thus reserve estimates labeled IPCC probably are more realistic than those of EIA, the latter including large estimates for undiscovered reserves.

Regardless of actual reserves, Fig. 1b shows that if CO2 emissions from coal were phased out over the period 2010-2030, and if use of unconventional fossil fuels (tar shale, tar sands) remained negligible, atmospheric CO2 would peak at 400-425 ppm. In that case improved forestry and agricultural practices, especially reforestation, could get atmospheric CO2 back beneath 350 ppm within a century or less. During the overshoot phase we might hope that ocean and ice sheet inertia may keep climate impacts tolerable, avoiding the most disastrous effects.
However, if coal use continues or expands (as it is now, see below), CO2 will be headed to the 500-600 ppm range, or even higher if unconventional fossil fuels such as tar shale are developed. In this “Damn the consequences! Full speed ahead with all fossil fuels!” case (a.k.a., business-as-usual), we will hand our children a planet that has entered a long chaotic transient period with climate changes out of their control, as the planet heads inexorably toward an ice-free state.

A critical fact is the long lifetime of CO2 emitted by fossil fuel burning. Half of a fossil fuel CO2 pulse disappears within 20-30 years, mostly into the ocean. However, much of the CO2, about one-fifth, is still in the air after 1000 years. Because of this long CO2 lifetime, we cannot solve the climate problem by slowing down emissions by 20% or 50% or even 80%. It does not matter much whether the CO2 is emitted this year, next year, or several years from now. Therefore, instead of a percent reduction in the rate of emissions, we must identify a portion of the fossil fuels that will be left in the ground, or captured upon emission and put back into the ground.

Mr. Gabriel and I did not disagree about the fact that the dangerous level of CO2 is very low, indeed, at today’s 385 ppm CO2 is almost surely already into the dangerous zone. The issue concerns how to keep maximum CO2 close to 400 ppm, thus retaining the possibility to get CO2 back below 350 ppm in a reasonable time. I contend that readily available oil (the big pools, being tapped already) inevitably will be used, and this oil-CO2 will end up in the air, because it is used in vehicles, where CO2 cannot be captured. Arguing otherwise requires an assertion that Russia, Middle East countries, and others will be willing to leave their oil in the ground.

Mr. Gabriel’s contention (echoed by Prime Minister Brown, see below) is that CO2 emission goals and a carbon cap-and-trade program will solve the problem, that a carbon cap can be tightened to yield the desired maximum atmospheric CO2. I reiterated several times that such contention implies that oil-producing countries can be convinced to leave their oil in the ground. We did not resolve this difference. In effect we agreed to disagree, as we were both trying to be cordial. As we left, Mr. Gabriel asked whether I was going to see Chancellor Merkel. I had no such appointment, but I believe it is important that she look at this matter analytically.

The fundamental issue is not widely appreciated, as shown by the fact that governments continue to talk about goals to reduce emission by 20%, 50%, 80% etc. No matter what number is chosen, this approach guarantees failure. It allows coal emissions to continue, new coal plants to be built and unconventional fossil fuels to be developed. “Success” in reaching a carbon emissions goal would not prevent readily available oil from being used – an emissions cap only slows the rate of oil use, with almost no impact on eventual climate change because of the long CO2 lifetime.

We cannot pretend that a goal for future CO2 emission reductions will solve the climate problem. If we continue to ignore obvious geophysical facts about the magnitude of fossil fuel reservoirs, our children and grandchildren will have little reason to forgive our obtuseness. The only practical way to keep climate change within tolerable limits is to cut off coal emissions and to have a price on carbon emissions that discourages unconventional fossil fuel (UFF) use.

Note that I am not arguing against a carbon cap. A carbon cap is useful, but insufficient. The danger of carbon caps and percent reduction goals is that they allow self-deception, a pretense that the climate problem is being solved. Unless they are accompanied by phase-out of coal emissions, they have practically no impact on climate change. By the way, a carbon tax (http://www.columbia.edu/~jeh1/mailings/20080604_TaxAndDividend.pdf) is more direct and effective, in my opinion, but either a cap or tax should be accompanied by 100% dividend, so that people have the resources to buy energy-efficient and carbon-free technologies and will recognize an honest way of dealing with the energy/climate problem.

Coal use with carbon capture should be allowed to compete with other energies, but coal should not be subsidized. Also utilities should not be allowed to use the “capture-ready” subterfuge, which is employed without any real intent of capturing the CO2. Given other damage caused by coal (http://www.burningthefuture.org/), to public health and the environment, and the inescapable fact that fossil fuels are finite and nonrenewable, it is likely that the best path is to move beyond fossil fuels sooner and leave much of the coal in the ground.

United Kingdom

The approach in the UK involved a number of people. At a dinner for VIPs organized by George Polk, I made the case re coal, that a moratorium on new coal-fired power plants is the essential first action. Lots of work by Matt Philips, more dinners, media coverage of my letter to the Prime Minister, and now a response of the UK government (http://www.columbia.edu/~jeh1/mailings/20080730_UKResponse.pdf):

Key phrases in this response: “For the UK, the starting point…is to recognize the central role of the EU Emissions Trading Scheme (EU ETS), particularly given the EU’s ambition that ‘cap and trade’ should form an integral part of a global climate change deal.” “A key priority for us is therefore to see this scheme strengthened…” The letter continues with sobering self-deception about how mandating ‘carbon-capture-ready’ will solve the coal problem.

This rationalization is almost identical to that of German Minister Gabriel. Any hope that implications of geophysical boundary conditions, when pointed out, would have a quick effect on policy-makers has proven to be unrealistic.

The case of Japan (below) makes the matter even clearer. Any follow-on to the Kyoto Protocol, to have any chance of success, must be dramatically different and account for geophysical facts.

An encouraging footnote: the opposition leader in the UK (Cameron) states that he would impose a moratorium on new coal-fired power plants.

Japan, the Kyoto Protocol, and Beyond

My letter to Prime Minister Fukuda was finished on the plane on the way to 4 July pre-G8 talk at UN University ; the final two paragraphs (suggesting that the G8 leaders write a letter to their grandchildren) were added on the bus ride from Narita Airport. When the letter was hand-delivered to the Prime Minister’s office they first declined to accept it, but relented upon learning that the letter was already discussed in major Japanese newspapers. Thanks to UN University for arranging the media interviews.

The letter to PM Fukuda presents geophysical facts within the letter per se, not in an attachment as in the letters to the UK Prime Minister and German Chancellor. This change was made because the attachments to the earlier letters were either not read or not understood. The geophysical data make it clear that the EU Emissions Trading Scheme would not be effective nor would the broad emissions reduction approach (a la Kyoto Protocol and suggested successors).

Figure 2. CO2 emissions by fossil fuel type in four countries. Note the different scales, emissions from the United States being several times larger than those of the other countries.

Figure 2, from the letter to PM Fukuda, shows the importance of coal for CO2 emissions, even in developed countries. Japan was an ardent proponent of the Kyoto Protocol, accepting a larger emissions reduction requirement than most other countries. But Figure 2 shows that Japan’s CO2 emissions actually increased rapidly, with the increase entirely due to increased coal use.

Japan’s total CO2 emissions are increasing despite the fact that Japan is held up as a role model for energy efficiency. Japan escapes attention in part by buying the right to pollute via the Clean Development Mechanism (CDM) of the Kyoto Protocol. The CDM, however, is a subterfuge and a disaster; it allows emissions of the worst pollutant, coal CO2, to increase, while supposedly reducing emissions in China and other developing countries. In fact, there is no effective constraint on CO2 emissions from China.

Germany and the UK reduced their CO2 emissions in the past quarter century (Figure 2), in both cases via reduced coal use (Germany halted dirty inefficient coal use in East Germany, the UK replaced coal with North Sea gas). If the UK, US and Germany, the countries most responsible on a per capita basis for excess CO2 in the air today1, , were to phase out coal emissions, their CO2 emissions would plummet as peak oil also takes effect. Of course major efforts to develop alternative energies and energy efficiency would be needed, but that approach would have many other merits. And by showing that this approach works, yielding clean air and water, and good jobs, it would become feasible to bring the rest of the world along. But instead, these governments are choosing to build new coal-fired power plants with 50-75 year lifetimes.

Figure 3. CO2 emissions by fossil fuel type for the globe and several countries. Note the four different scales.

The global impact of the failure of these countries to provide leadership is revealed in Figure 3. The surge in global CO2 emissions is mainly a surge in coal use. The surge is mainly in the East, especially China, but the West cannot make a peep about that, because the West is building coal plants itself, has many more on the books, and presents no effective alternatives. In addition, the West is responsible for most of the excess CO2 in the air today1,3.

Figure 3 also shows that coal use in Russia is modest and not increasing. Thus the common assertion that Russia is a wild card that would prevent successful control of global warming is diminished by realization that the primary requirement is phase-out of coal emissions.

In summary, policy implications of the geophysical boundary conditions include:

(1) Annual CO2 emissions, and thus percent reduction of annual emissions, is not an appropriate metric for controlling climate change. Lifetime of CO2 is so long that slowing CO2 emissions has little effect on climate change. Instead, we must limit the total fossil fuel CO2 emission.

(2) Phase-out of coal emissions is the sine qua non for climate stabilization. Oil and gas, the most convenient portable fossil fuels, are sufficiently abundant to carry the world well into the dangerous CO2 zone, but not irretrievably so. If coal emissions (not necessarily coal use) were phased out promptly (within ~2 decades, which probably would require phase-out in the West within ~1 decade), it would be practical to get back to CO2 levels lower than the present day amount. Coal is by far the dirtiest of the conventional fossil fuels, providing additional reason to target it for phase-out. Conclusion that the largest pools of oil and gas will be used, and that oil and gas reserves are smaller than coal reserves, does not imply that it makes sense to extract every last drop of oil and gas. Given the need to move beyond fossil fuels in any case, and the need to get back to a safe level of atmospheric CO2, policy-makers should consider actions that move beyond fossil fuels as rapidly as possible, preferably leaving in the ground the oil and gas that is more difficult to extract or located in environmentally sensitive regions.

(3) Countries cannot be allowed to “buy out” of coal phase-out via supposed reforestation or reduction of non-CO2 forcings. Sequestration of CO2 via improved forestry and agricultural practices is needed to reduce atmospheric levels below current levels. If reforestation CO2 reductions are used up as a trade-off for coal emissions it will be difficult, if not impossible, to get CO2 levels back below current levels. Similarly, the limited potential for reduction of non-CO2 forcings is needed to balance the positive (warming) climate forcing due to other non-CO2 effects, especially expected reduction of reflective aerosols.

(4) Unconventional fossil fuels, including tar shale, tar sands, and methane hydrates, which contain more carbon than coal and other conventional reserves, must not be widely developed.

Source: Dr. James Hansen’s trip report, reposted permission