"As evidence accumulates that we may already be witnessing the early signs of global climate change, the ability to explain this issue to both policymakers and the general public becomes ever more urgent," said UNEP Executive Director Klaus Toepfer.
"The challenge facing generalists is that the subject is so complex and often highly specialized. Much of our understanding of climate change comes from sophisticated computer-based models, data sets, and theoretical insights. Decision-makers need insight into such scientific information if they are to craft and implement effective solutions," he said.
The visual information contained in the Vital Climate Graphics folder makes it possible to grasp complex facts more quickly and fully than would be possible through simple text. The graphical impact is supported by additional written details that help to fill in the picture. The graphics are available as overhead slides and can be obtained via CD ROMs, booklets or the Internet. They are available on the web at http://www.grida.no/publications/vg/climate.
The Graphics are based on the reports of the Intergovernmental Panel on Climate Change (www.ipcc.ch), which was established in 1998 by the United Nations Environment Programme (www.unep.org) and the World Meteorological Organization (www.wmo.ch). The IPCC's 1995 Second Assessment Report is widely respected as the most authoritative source of climate change information available. The Graphics will be updated after the forthcoming Third Assessment Report, scheduled for publication in 2001, becomes available. The first set of graphics to be released focuses on climate change impacts.
A brief introduction to climate change science
Human activities are releasing greenhouse gases into the atmosphere. Carbon dioxide is produced when fossil fuels are used to generate energy and when forests are cut down and burned. Methane and nitrous oxide are emitted from agricultural activities, changes in land use, and other sources. Artificial chemicals called halocarbons (CFCs, HFCs, PFCs) and other long-lived gases such as sulphur hexafluoride (SF6) are released by industrial processes.
Rising levels of greenhouse gases are expected to cause climate change. By absorbing infrared radiation, these gases control the way natural energy flows through the climate system. In response to humanity's emissions, the climate will somehow have to adjust to a "thicker blanket" of greenhouse gases in order to maintain the balance between energy arriving from the sun and energy escaping back into space.
Climate models predict that the global temperature will rise by about 1-3.5°C by the year 2100. This projected change is larger than any climate change experienced over the last 10,000 years. It is based on current emissions trends and assumes that no efforts are made to limit greenhouse gas emissions. There are many uncertainties about the scale and impacts of climate change, particularly at the regional level. Because of the delaying effect of the oceans, surface temperatures do not respond immediately to greenhouse gas emissions, so climate change will continue for many decades after atmospheric concentrations have stabilized. Meanwhile, the balance of the evidence suggests that the climate may have already started responding to past emissions.
Climate change is likely to have a significant impact on the global environment. In general, the faster the climate changes, the greater will be the risk of damage. The mean sea level is expected to rise 15-95 cm by the year 2100, causing flooding of low-lying areas and other damage. Climatic zones (and thus ecosystems and agricultural zones) could shift towards the poles by 150-550 km in the mid-latitude regions. Forests, deserts, rangelands, and other unmanaged ecosystems would face new climatic stresses. As a result, many will decline or fragment, and individual species will become extinct.
Human society will face new risks and pressures. Food security is unlikely to be threatened at the global level, but some regions are likely to experience food shortages and hunger. Water resources will be affected as precipitation and evaporation patterns change around the world. Physical infrastructure will be damaged, particularly by sea-level rise and by extreme weather events. Economic activities, human settlements, and human health will experience many direct and indirect effects. The poor and disadvantaged are the most vulnerable to the negative consequences of climate change.
People and ecosystems will need to adapt to future climatic regimes. Past and current emissions have already committed the earth to some degree of climate change in the 21st century. Adapting to these effects will require a good understanding of socio-economic and natural systems, their sensitivity to climate change, and their inherent ability to adapt. Many strategies are available for adapting to the expected effects of climate change.