The IPCC: the voice of authority on climate change
In November 2007, the United Nations Intergovernmental Panel on Climate Change (IPCC) finalised its Fourth Assessment Report (AR4), summarising six years of rigorous scientific research and analysis of the way the world’s climate is changing.
This landmark report will certainly not be the last word in the climate change debate, but it establishes beyond all reasonable doubt that greenhouse gas emissions from human activity are generating global warming which could have a devastating impact on people, our economies and our environment.
Together with former US Vice-President Al Gore, the IPCC was awarded the 2007 Nobel Peace Prize – one of the most prestigious awards in the world – for their efforts to improve our knowledge about man-made climate change and lay the foundations for action to combat it. The award of a peace prize underlines the extent to which climate change is being recognised as a threat to global security.
Al Gore has already won an Oscar for his pioneering documentary An Inconvenient Truth, which has alerted millions of people around the world to the dangers of climate change.
The IPCC was set up in 1988 and brings together input from some 2,500 leading experts and scientists all around the world. During 2007 it has published three detailed analyses, focusing on the latest science regarding climate change, its potential impacts, and ways to mitigate it. The final Synthesis Report published in November 2007 brings together all three strands of the AR4. What makes the IPCC influential is the rigour of its scientific approach. The reports’ authors act independently of governments and do not receive payment for their years of dedicated work.
A dangerous truth
So what does the IPCC synthesis report tell us? It confirms that climate change is a reality. For example:
- Eleven of the last 12 years have been the warmest in history.
- The rate of sea level rise has almost doubled from 18 cm per century in 1961-2003 to 31 cm per century in 1993-2003, accelerated by melting glaciers and polar ice.
- Satellite data show that Arctic sea ice has been shrinking by 2.7% per decade since 1978.
- Cold nights and frosts are rarer, and heatwaves more frequent.
- Over the last century, rainfall has increased in northern countries, but declined around the Mediterranean, Africa and southern Asia, extending areas of drought.
Temperatures are rising faster and faster. Over the past 100 years the global average temperature has gone up by 0.74ºC. If global emissions of greenhouse gases carry on growing as they are now, our planet will most likely be between 1.8ºC and 4.0 ºC 6.4ºC warmer than today by the end of this century – and in the worst case up to 6.4°C hotter. Even the lower end of this temperature range would represent an enormously rapid change which many species and ecosystems would have difficulty coping with.
The panel never wants to exaggerate its conclusions, and therefore it works on a carefully calibrated range of certainties. So when the report states with “high confidence” that this warming is due to human activity, that’s close to definite in scientific terms. Emissions of man-made greenhouse gases have risen a massive 70% worldwide since 1970, with the result that concentrations of carbon dioxide (CO2) and methane (CH4) far exceed the natural levels found in the atmosphere over the last 650,000 years.
Facing the worst
The consequences could indeed be devastating. The evidence points to more tropical cyclones and storms in the north. Melting polar ice sheets would raise sea levels and drown low-lying countries. Oceans will become more acidic, destroying corals and sealife. In Africa, up to 250 million people could be short of water by 2020.
The situation will be particularly serious if temperatures rise more than 2ºC above pre-industrial levels. Above that limit, the IPCC warns, the impacts of climate change could become increasingly sudden or irreversible. This is why the European Union is determined to ensure the international community takes action to prevent warming from going beyond 2ºC. t One of the consequences of going beyond 2° is that 20-30% of species are likely to face extinction.
Still time to act
But it’s not all bad news. The IPCC points out that steps can be taken now to slow down or adapt to climate change, and that such measures make economic sense. Doing nothing could cost the Earth, in terms of damage to the natural world and our economies, but harnessing our knowledge will mean savings in all directions. Many technologies and practices to help us reduce emissions – through greater energy efficiency, renewable energy sources or better waste management, for instance – are already available or in the pipeline and likely to become available within the foreseeable future.
The problem is that barriers – such as conflict, poverty and lack of information – often stand in the way of exploiting these technologies. Governments around the world need to prioritise the removal of these obstacles, says the IPCC. Unless climate change is controlled, all humanity’s other goals of progress and sustainable development may be in danger.