Climate Change 2007: The Physical Science Basis

The Intergovernmental Panel on Climate Change fourth assessment report is the culmination of six year’s work by scientists from more than 130 countries, including 2500 expert reviewers. The Working Group I report, Climate Change 2007: The Physical Science Basis, assesses the latest scientific knowledge on, and reasons behind climate change, looks at how the climate has already altered and how a range of different scenarios may have an impact in the future.

Among other findings, the report strongly emphasizes that warming of the climate system is inevitable, evidenced by observations of increases in average global air and ocean temperatures, widespread melting of snow and rising sea levels. The main difference between this report and the one issued in 2001 is that the IPCC now qualifies human activities as the “very likely” (probability is more than 90%) cause of global warming. “The global increase in carbon dioxide concentrations are due primarily to fossil fuel use and land-use change, while those of methane and nitrous oxide are primarily due to agriculture”, the report stressed.

In addition, the consensus report from IPCC Working Group I, projects that without further action to limit greenhouse gas emission, the average global temperature is likely to rise by a further 1.8-4.0°C this century, after increasing by over 0.7° in the past 100 years.

International reactions

In response to the challenge, the International Energy Agency (IEA) stressed the “urgent need for global coordinated action”, and the Environment Commissioner, Stavros Dimas, has urged the international community to start negotiations on a comprehensive new global climate change agreement. As proposed by the European Commission in January 2007 (EC Communication “Limiting global climate change to 2 degrees Celsius, the way ahead for 2020 and beyond”), Dimas said that EU member states should aim for a 20% cut in greenhouse gas emissions by 2020. Furthermore, “to stabilise global emissions of greenhouse gases, the next step must be for the group of developed countries to cut their emissions to 30% below 1990 levels by 2020”, the Commissioner highlighted.

In the meantime, the publication of the report has also triggered renewed calls for the creation of a single UN environmental body, to replace the multitude of agreements and organisations that currently work in the environmental field.

EWEA believes that the international community should take immediate action and put in place strong greenhouse gas abatement policies. We have a ten year time window to take corrective action. Limiting carbon from fossil fuels and the large scale use of renewable energy sources are major solutions that go hand-in-hand, and should be at the heart of climate change policies. Renewable energies, such as wind power, play a central role in reversing the build up of greenhouse gases in the atmosphere. Wind energy in Europe, in particular, is expected to avoid emissions equal to one third of the EU’s Kyoto obligation. EWEA considers that if the necessary reductions of CO2 and other emissions from electricity generation are to be met and climate change challenges to be tackled, a consistent policy framework for investments and technological innovation in wind power and other renewable electricity sources is essential.

Next Steps

The full IPCC climate science report will be released later this year. In the meantime, three other chapters will be published, which will look at the probable impacts of climate change, options for adapting to these impacts and possible routes to reducing green house gas emissions.