Many will long remember the summer of 2003. ‘Long’ means until about 2040. In fact it is said such summers will be the norm by then. In 2060 senior citizens will recall nostalgically the cool temperatures of 2003. This is forecast for Europe’s climate by the IPCC’s Fourth Assessment Report if CO2 emissions are not cut back quickly. Four scientists announced this and other uncomfortable insights at the Climate Symposium at ETH Zurich on Friday 28 September 2007, which was followed by a podium discussion with Federal Council member Doris Leuthard.

Much more greenhouse gases

As the Fourth IPCC Report outlines, the climate prospects up to 2100 really are unpleasant. Thomas Stocker, Professor of Climate and Environmental Physics, University of Bern, said that in the past 20,000 years the concentration of all the greenhouse gases in the atmosphere had never been as high as it is today. This is shown by measurements of the various gases trapped in ice bubbles. At a concentration of 386 ppm, carbon dioxide is now more than a quarter above the average value in the past 650,000 years.

CO2 and other greenhouse gases are closely linked to temperature. When the concentration of these gases is taken into account in models, the predicted feverish temperature curves point upwards, as observed. However, if the calculation in the models is carried out without the greenhouse gases, the temperature curve continues to run more or less in a straight line. Stocker concludes that “The warming in the past 50 years cannot be explained without human factors.”

Water equilibrium turned upside down

Increasing temperatures change the Earth’s water balance. This means dry regions like the Iberian Peninsula or South Africa become even dryer while wetter areas nearer the North Pole will receive more precipitation, which will occur as heavy downpours. Temperatures will also rise faster and higher in the high latitudes than in the low ones, and so the researchers foresee increases of up to 7 degrees for regions above the Arctic Circle by 2100.

The living environment, i.e. plants and animals, will also suffer. Pack-ice, coral reefs and other marine habitats as well as wetlands, flowing watercourses, tundra and savannah: the list of ecosystems affected by climate change is almost endless.

About 20 to 30 percent of the higher animals and plants have a greater risk of extinction if average global temperatures rise by 1.5 to 2.5 degrees compared to the present day. However, ETH Zurich researcher Andreas Fischlin says there are regional differences in the extinction risk. In an extreme case four out of five plant or animal species could disappear. For example a threat of death hangs over almost three quarters of all the higher plants in South Africa’s unique Fynbos vegetation with its 5,600 or more endemic plants.

Soils become CO2 sources

Climate change also affects habitat functions. At present the ground absorbs large amounts of CO2 which thus disappears from the atmosphere for the time being. If current emissions and changes in land use continue, this system might overturn. Habitats on land will become a net source of CO2. Terrestrial ecosystems might act as sinks until 2030 as a maximum, but from 2050 onwards they start to emit CO2. According to Fischlin: “That will probably accelerate climate change even more.” The researcher is visibly worried in particular that the resilience of ecosystems may become exhausted during the present century. Resilience is the term ecologists use to describe an ecosystem’s ability to bounce back to its normal state after an extreme event.

Lucky for wine-growing

However, the researchers’ report was not all bad news. Climate physicist Manfred Stock from the Potsdam Institute for Climate Impact Research said the production conditions for wine-growing will shift northwards. He said it was already possible to produce good wine in Potsdam now, and the wines of the Austrian province of Burgenland would excel those from the Bordeaux region in terms of quality.

However, by and large he was also sceptical. He warned that the Amazon rain forest region might collapse and that the monsoon system was endangered. He also said researchers had discovered that very powerful typhoons are more frequent, are now originating in the South Atlantic and are following new tracks.

Stock said “Adaptive actions are promising if the warming is no more than two degrees.” More than two degrees was probably unmanageable. However, the German physicist thinks this target is achievable. He said what must now happen is the third industrial revolution based on renewable energies.

Little happening in the political arena

However it is uncertain whether this two degree target will be achieved. Renate Schubert, ETH Zurich Professor of Economics, sees no changing trend in energy consumption. She says “Little is happening individually and politically.” 80 percent of the world’s energy sources are fossil fuels. These are also being used inefficiently.

Schubert put forward a whole sheaf of measures against climate change. These have a national or international approach. Nations can enact compulsory measures or create incentives appealing for a voluntary response by business and individuals. For example at an international level compensation payments for preserving forests or a certification requirement can achieve the aim. However, the professor also said all measures had advantages and disadvantages. For example voluntary actions were ecologically inefficient but were better accepted.

However, she said there was still no easy solution to climate change. According to Schubert, “The choice of measures depends on how the aims and guiding principles – such as global justice – are weighted, and that depends on the players in the individual countries.” She says another problem is the relatively low perceptibility of climate change. “The future is so far away and the remoteness of the scenarios is too great.” This is why the willingness to get involved in changes is weak. Schubert said “The importance of taking action for the future is not being appreciated properly.”

Even if the sheer size of the problem is disheartening: Renate Schubert also showed how nations or every individual person can act sensibly. At a national level, for example, she thought a CO2 tax was appropriate; consumers should drive cars with low CO2 emissions or buy energy-efficient household appliances. Science could make a contribution by spreading science more widely among the public and by the individual disciplines, especially engineering or the natural sciences, collaborating more closely with social sciences and the humanities.

A CO₂-neutral Switzerland thanks to emissions trading

The second part of the evening comprised a lecture by Federal Councillor Doris Leuthard together with a podium discussion introduced by ETH Zurich President Ralph Eichler. He said science’s task was to identify problems, analyse them and indicate possible ways to solve them. Industry implemented the knowledge and it was for politicians to define the framework conditions.

The Minister of the Economy formulated ambitious CO2 emission reduction targets for Switzerland: “I suggest we aim for a reduction target of 100 percent.” Leuthard plans to achieve this target mainly via international trading in emissions certificates. She said that was an appropriate solution though not a cheap one because Switzerland had the world’s smallest CO2 intensity. Compared to other industrialised nations, the potential for reduction was small and costly. The Swiss public would also hardly accept drastic measures as a solo effort.

Criticism from a Nobel prize-winner

By spending the same amount abroad, Switzerland could reduce more CO2 than it could on actions taken at home, and could make a maximum contribution with a 100 percent reduction target. In addition the technology transfer would help bring about the cleaner industrialisation of developing and threshold countries. This would allow what are known as “grey emissions” to be reduced, i.e. CO2 production on imported goods. Finally Switzerland would be able to prepare a world-wide emissions trading system.

During the discussion, Nobel prize-winner Richard Ernst warned against viewing emissions certificates trading as a panacea. The system reminded him of the unholy trade in indulgences which the Catholic Church had also abandoned. It was untenable for Switzerland to continue producing exactly the same amount of CO2 and simply buy a good conscience with money.

Backing from the Professor of Economics

On the other hand Renate Schubert agreed with the proposed reduction target. She said the “100% CO2-free” label had symbolic power. Public knowledge about climate change needed to increase. A lack of knowledge was one reason why too little was happening. Another lay in the instruments leading to a reduction. She said it was difficult to assemble a set of measures that fulfilled all the four guiding principles of “ecological efficiency”, “economic efficiency”, “the precautionary principle” and “global justice”.

Thomas Stocker did not oppose environment certificates in principle, but feared buyers would dominate the global market with the passage of time if many countries joined in. Plan B would then be needed. However, Federal Councillor Leuthard assumed that the novel system would not be valid forever, but the new instrument could be implemented quickly without political wrangling – in contrast to a CO2 penalty tax in Switzerland.

Dramatic situation scarcely recognised

Andreas Fischlin stressed emphatically that action was needed. It was justifiable to take all measures that contributed to limiting global climate warming to two degrees Celsius, as the IPCC Report demands. This target was achievable only through the greatest sacrifices. Overall emissions would need to start falling from 2015 onwards and the industrialised nations would have to reduce their CO2 emissions by up to 95 percent by 2050.