CLIMATE target ‘will be missed’. It may already be too late bring climate change under control, scientists warned. New research show that without an early and steep cut in greenhouse gas emissions, global temperatures are not ‘likely’ to remain below the target - 2°C (3.6F) higher than pre-industrial levels. Emission levels will have to drop to 44 billion tonnes by 2020. The report in journal Nature Climate Change states: “There are significant risks that the 2°C target, endorsed by so many nations, is already slipping out of reach”.
Scientists warn of ‘catastrophe’ if there is no deal at climate talks in Copenhagen and Durban as the publishers a new emergency ‘red’ list. The officials around the world raised the political stakes on climate change when it published new issues of the world that details the likely effects of failure to cut greenhouse gas emissions. The environmental impact of an average 4°C rise in global temperature, which the government’s scientists, said would be “disastrous”. A study such a 4°C rise could come as soon as 2060 unless urgent and serious action taken to reduce emission.
Rich countries have deep carbon footprints. Retailers have announced plans to cut its carbon footprint by one-third by 2030, by changing its fridge technology. Also Europeans want assistance for poorer countries to come from existing cash pot. If the scientists are right, then the international community cannot afford a decade of delay in concluding a deal on climate change. Four-fifth of the growth in emissions between now and 2030 will come from those developing nations.
Amazon could shrink by 85% due to climate change, scientists say. With high levels of climate change, large areas of the Amazon forest could be lost through either drought stress on vegetation or the uncontrolled spread of fire. This depends largely on whether rainfall will decrease in Amazonia. While some climate models suggest rainfall may increase, some of the more realistic models project severe drying in the Amazon, increasing the risk of major droughts.
Agriculture is highly exposed to climate change, as farming activities directly depend on climatic conditions. Climate change directly affects crop productivity and food production. Changes in the regional differences in climate patterns may widen production and consumption gaps between the developed and developing world. Current assessments are mainly limited to alterations in mean climate, but extreme weather or glacial retreat would potentially accelerate declines in productivity further.
Agricultural yields are expected to decrease for all major cereal crops in all major regions of production, once the global average temperature increases beyond 3 ºC. For some crops the yield could decrease by over 20% at low latitudes, where the impact will be greatest. This could result in tens to hundreds of millions of additional people (roughly a 10-20% increase), at risk from hunger. Most of this increase is expected in Sub-Saharan Africa, and in some parts of south Asia and Central America, particularly for child malnutrition. For the population at 2050 the increase in the number of malnourished children could be as high as 24 million.
In particular, changes to water quality, quantity and availability will be an impact of ongoing climate change in many areas. A rise in global average temperature of 4 ºC (7 ºF) would have a substantial effect on river flows and the availability of water. For the population rise at 2080, without climate change, just over 3 billion people, out of a global population of 7.5 billion, could be living in areas with limited per capita water availability (less than 1000m3/person/year).
By reducing river run-off, climate change could mean that significantly less water was available to approximately 1 billion of these people (range 0.4 to 2 billion), substantially increasing the pressure of managing water supplies. In addition, as glaciers retreat, communities relying on glacier melt-water will also come under further threat.
Sea levels are predicted to rise twice as fast as was forecast by the United Nations only two years ago. Sea-level rise is an inevitable consequence of increasing global temperatures. Low-lying coastal areas will become more vulnerable to flooding and land loss. As these areas often have dense populations, important infrastructure and high value agricultural and bio-diverse land, significant impacts are expected. At the beginning of the 21st Century, an estimated 600 million people live no more than 10 metres above present sea level.
South and East Asia have the highest populations living in low-lying deltas, but small islands are also vulnerable from sea-level rise and storm surges. Flooding from sea-water would cause loss of land, crops and freshwater supplies, posing a risk to stability and security. For some, forced migration will be inevitable.
The largest temperature increases are in the Arctic and the Antarctic Peninsula. An average global temperature rise of 4 ºC (7 ºF) is not uniform as oceans heat more slowly than the land, and high latitudes, particularly the Arctic, will have larger temperature increases. The temperature of the very hottest days will also increase and many areas of high population density will see a larger change in extreme high temperatures. This will have a significant impact on health. Temperature rises will impact water availability, agricultural productivity, the risk of fire, the melting of ice sheets and the thawing of permafrost. Commercial activity will also be affected by loss of productivity in hotter conditions or the cost of maintaining cooler working environments.
Heat-related mortality and other adverse health impacts are likely to increase considerably, even when acclimatisation, adaptation and fewer cold-related deaths are taken into account. In 2003 for instance, the European heat wave was responsible for around 35,000 additional deaths.
Acceleration of global warming due to carbon-cycle feedbacks in a coupled climate model. The 20th Century rise in CO2 concentration was only 40-50% of the actual rate of emissions, because the rest was absorbed by the world's ecosystems and oceans. This process may be damaged by climate change, so that the impact of emissions on atmospheric concentrations could be greater in the future. At 4 ºC (7 ºF) increase in global average temperature, the proportion of CO2 emissions remaining in the atmosphere could rise to as much as 70%. The longer emission cuts are delayed, the less effective they will be in stabilising CO2 in the atmosphere.
