First Assessment Report – 1990 After 18 months work, the chairman of the IPCC working group looking at the impacts of climate change wrote the issue was potentially the greatest global environmental challenge facing humankind. That first report was based on findings that if CO2 levels in the atmosphere were to double, this would deliver a global temperature rise of between 1.5C and 5C, with sea levels rising by about one metre by the end of the 21st century. The worlds polar regions would warm at double the rate. Natural ecosystems would face significant consequences from climate change. Major health impacts were possible because of changes to the availability of water and food and from heat stress and increased spread of disease. Poorer countries were the most vulnerable. The working group thought then that some of the greatest impacts for developed countries may be determined by policy responses such as regulations on fuel and emission fees. The report also warned: Global warming will accelerate sea-level rise, modify ocean circulation and change marine ecosystems with considerable socioeconomic circumstances. One major uncertainty was the risk climate change might pose to food supplies. The report said that on balance global food production could be maintained at the same level, even if the costs of doing that remained unclear. Second Assessment Report – 1995 Some of the worlds ecological systems could take centuries to reach a new equilibrium, warned the IPCCs second major assessment report (SAR) into the impacts of climate change, building on the report from five years earlier. Coastal systems are at risk, said the SAR, having major negative effects on tourism, freshwater supplies, fisheries, and biodiversity. One third to a half of the mass of mountain glaciers could disappear within 100 years. In the oceans, SAR concluded that sea levels would rise, ocean circulation could be altered and the amount of sea ice would drop. Serious concerns were raised about water supplies for everything from power generation to domestic supplies. The panel was still uncertain about the affects of climate change on food supplies, but there were concerns the risk of hunger and famine could increase among the worlds poorest. Climate change is likely to have wide-ranging and mostly adverse impacts on human health, with significant loss of life, said the report. Exposure to extreme weather events could raise the risk of increased death, injury [and] psychological disorders. In other news, a company called eBay is created, former American Football hero O.J Simpson is found not guilty of double murder and Forrest Gump wins the Oscar for best picture. Third Assessment Report – 2001 Projected climate changes during the 21st century have the potential to lead to future large-scale and possibly irreversible changes in Earth systems resulting in impacts at continental and global scales. So goes the third major IPCC report into the impacts of climate change, which repeats previous warnings and then adds lots more. Most sub-tropical and tropical areas will see a fall in crop yields as temperatures go up. In mid latitudes, yields might improve if temperature rises are only low, says the report. Urban populations are likely to be impacted by rises in temperature extremes affecting particularly the elderly, sick, and those without access to air-conditioning. In some temperate countries, the number of people dying in the winter from cold could outnumber the increased summer deaths, but the evidence for this is limited. In other news, the world gets Wikipedia, iPods and lots of people go and watch movies about bespectacled young wizards and hobbits. Assessment Report Four – 2007 Its all of the above, again, with the release of the fourth assessment report (AR4) in 2007. Many millions more people are projected to be flooded every year due to sea-level rise by the 2080s, the report says. If global average temperatures rise between 1.5C and 2.5C, then approximately 20 to 30 per cent of plant and animal species assessed so far are likely to be at increased risk of extinction. The message on global food production is still mixed, but the panel concludes that if temperatures get above a range of between one and 3C, then food production drops. For the fourth time, the report is clear that poorer communities are the most vulnerable with small island nations especially vulnerable. Climate change will affect the health status of millions of people with increases in malnutrition and impacts for child development. Heatwaves, floods, storms, fires and droughts will increase deaths and injury. The IPCC still says that in some temperate countries there might be fewer deaths from cold exposure, but overall, the report says, it is expected that these benefits will be outweighed by the negative health effects of rising temperatures worldwide, especially in developing countries. For Africa, the year 2020 will see between 75 and 250 million people exposed to increased water stress due to climate change. The Asian mega deltas are warned again about the increased risk of flooding from storm surges and sea level rise. In Australia and New Zealand, some ecologically rich sites including the Great Barrier Reef, the Queensland Wet Tropics, the Kakadu wetlands, sub-Antarctic islands and alpine areas are deemed to be at risk of significant biodiversity loss. Some of these areas will see impacts as early as 2020. Increased drought and fire will cut production in agriculture and forestry by 2030 over much of southern and eastern Australia, and over parts of eastern New Zealand. Negative impacts for Europe will include increased risk of inland flash floods, and more frequent coastal flooding and increased erosion. If emissions remain high, then parts of Europe will see 60 per cent of all species will be gone by the year 2080. Latin America is warned some of its most important crops and livestock will be impacted with adverse consequences for food security. In other news, mortgage defaults in the US spark a global credit crunch, people queue for a seventh book about a teenage wizard and bands perform at Live Earth climate change concerts around the world. Assessment Report Five - 2014 You can find the latest cheerful IPCC report here. More than 300 authors and editors from 70 countries put it together, with more than 400 contributors and over 50,000 comments. But if we go back to brass tacks, its worth asking how the world has reacted to these repeated warnings. Since 1990, annual global greenhouse gas emissions from burning fossil fuels have gone up 60 per cent.
Posted on: Tue, 01 Apr 2014 04:02:13 +0000
Trending Topics
Recently Viewed Topics
© 2015