GreenPrices Weekly, 17 July 2007 – Everyone seems to agree that global warning should not exceed 2 degrees Celsius. But what is actually needed to achieve this goal by 2050 and are we on the right track? Researchers from the German Aerospace Centre (DLR), Ecofys, Greenpeace and EREC show in the Energy Policy journal how it can be done. They recommend their work should be adopted as a future benchmark in stead of the Business-as-Usual scenario.
Iceberg near Baffin island - Ansgar Walk (WikiCommons)
The 2 degrees C target is based on the IPCC results. On the same grounds, the European Council reached a political consensus that 2 oC is the maximum allowable global temperature rise, and the EU energy targets are a first step in that direction. If global warming is to be limited to 2oC, the concentration of CO2 equivalent in the atmosphere should not exceed 450 ppm, which in turn means that global emissions should be reduced to10 gigatonnes/year by 2050, 60% of the current levels. Assuming that the world population reaches 9 billion by 2050, the per capita emissions should not exceed 1 tonne CO2 per year. To put it in perspective, that is the current per capita emissions for Africa. Europeans emit 10 tonnes CO2 per capita per year and Americans emit double that. Does that mean that by 2050, we will all have to live like Africans? No, say the researchers, there will be no need to freeze in the dark.
The problem is that even the most far-fetched energy scenario falls significantly short of the 2 degree climate target. For 2050, the most extreme IEA scenario for example forecasts the same CO2 emissions as today, even though a global relative reduction of 40% is needed. To solve this shortcoming, the authors of the new report take the 2 degree limit as their starting point to then backcast what would be necessary to achieve that goal. That approach is very reminiscent of the Energy Revolution scenario published by Greenpeace last year and written by Sven Teske, one of the co-authors of the 2 degree scenario.
The task to radically reduce CO2 emissions gets even more difficult because of two principal choices in the 2 degree scenario put forward in the new report: no new nuclear power plants combined with a gradual phasing out of nuclear energy towards 2040, and no use of carbon capture and storage technology, because of the current technical and economical uncertainties. Most of the CO2 reduction results from improved energy efficiency; from energy not used. Most of these Œnegawatts¹ come from more efficient (hybrid) passenger cars, improved energy efficiency in industry, improved heat insulation, efficient freight vehicles up to more efficient lighting and the increase of the use of secondary aluminium. In all, improved efficiency should halve the global energy use, but because global energy use will double under the business as usual scenario, global energy use by 2050 will thanks to all the efficiency efforts – roughly stay the same as now: 420,000 Petajoule/year (thousand million million Joules per year).
The amount of energy may stay the same; but the energy mix changes dramatically. The share of renewable energy will increase from the current 13% to 50% by 2050. The largest part will come from biomass, followed by solar energy, wind, geothermal and ocean energy.
According to the study, the availability of renewable sources is abundant and largely covers the global energy need, even in the case of biomass. By 2050 the demand for biomass is estimated to reach 105 Exajoule (million million million Joule), while the global potential for biomass is estimated to be 3 to 6 times higher.
Also, the renewable energy industry (co-author Arthourous Zervos is President of the European Renewable Energy Council) says it can definitely deliver even more energy than projected in the 2 degree scenario if demand is higher.
Developing economies should choose renewable energy and apply energy efficiency to make their economic growth practically carbon-neutral. The OECD countries should reduce their emissions by 80% by 2050 by increasing energy efficiency and by switching to renewable sources.
Sound as this may be, the gap between policies and the 2 degree climate target remains. ²It is obvious that strong action policy is required to close the gap between the well-known climate protection policy commitments and the actual development of the world system,² say the authors. “We strongly suggest to use a target-orientated scenario like the 2 degree scenario rather than a business as usual based Œreference¹ as a benchmark to assess future policy options.”
More information: Krewitt, W. et al., The 2 degrees scenario A sustainable world energy perspective. Energy Policy (2007), doi:10.1016/j.enpol.2007.04.034
copyright © Het Inzicht / Jos Wassink, 2007
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