Impacts of Climate Change
Anthropogenic activities are bringing about changes in temperature, precipitation, sea level, wind patterns and other climatic variables; these, in turn, will have impacts in many areas, including human health, ecosystems, forests, agriculture, coastal and low-lying areas, water resources and economies
Impacts of climate change currently involves the use of numerical models to investigate the effect of system changes. Uncertainty is inherent in all the various different steps in the modelling chain, from greenhouse gas emissions right through to climate projections. The same is true of the impacts modelling step. Models will need to be run many times with a range of different temperature and rainfall inputs from different climate models, to explore the effect of uncertainty in the climate modelling; this step will then need to be repeated with different formulations.
We would ideally do all our modelling on the very finest of spatial and temporal scales, in practice we can often learn a great deal about the behaviour of the climate system by using models of relatively coarse resolution. Once we reach the impacts end of the modelling chain, however, and wish to find out the ultimate impact of global climate system changes, our need for information on the very smallest of spatial scales and the shortest of timescales becomes more pressing. Crops, for example, will be affected by short-lived weather events which bring extreme amounts of rainfall as well as more systematic changes in temperature and rainfall. The most comprehensive studies will require results from an ensemble of regional climate models to explore the full range of possible uncertainties.
Effects of Climate Change
Human effects - Extremes of heat and cold effect humans in direct terms through increased fires, droughts,storms and floods events. But less directly through climate changes through infectious diseases, malnutriton, diarheol and cardio -respiratory diseases. Other beneficial effects include an estimated reduction in malaria and dengue fever. Also fewer cold related diseases.
Agriculture - Drought. floods and extreme heat could destroy crops and heat-resistent crops need to be developed as a policy outcome. Pressure on prices could lead to further hunger. On the beneficial side there should be less frost-related destruction of crops.
Ecosystems, forests and coastal regions - Death of corals due to bleaching caused by rising temperatures and acidification of the seas. Coastal wetlands, mangroves and salt marches will be negatively impacted becuase of the rising sea levels and increased coastal erosion. 33% to 44% is likely to be lost with an increase of less than one meter in sea levels. These regions include, the Maldives, Mozembique and Bangladesh.
The earth's Cryosphere (ice and snow) will be affects due to snow melt. The melting of Greenland and West Antartic glaciers would add 5 and 7 meters to the world's oceans. On the otherhand it should reduce freighter costs as they can now pass through previously frozen seas.
Loss of unique vegetarian systems will endanger species. More species are likely to go extinct with as little as 2.5c increase Globally, a modest increase in the productivity of forests is projected in the short to medium term, with large regional variations around this trend.
Water sources - Although there could be an increase in precipitation it is likely to reflected in wetter areas getter wetter where it is not needed and dry areas getting drier where they do. Also more frequent floods means that the water will cause damage rather than helping the regions it effects. And overall the availability of clean water will reduce.
Regions dependent on meltwater (a sixth of the population) will see a siginificant reduction to access to water.
Economics - Increase in insurance claims and premiums or withrawls of coverage. Energy prices will increase. For instance additional demand for air-conditioning which will have a postive forcing effect as it will require the burning of fossil fuels. Foods is likely to get scarcer and food prices increasing. One policy outcome might be the building of environmentally friendly Nuclear Power Stations, which will require the production cardon dioxide releasing concrete.
Conclusion
There are many effects both negative and beneficial. It is difficut to determine how these variables will interplay but we should take the presumption that the overall impact will be negative. However, will the increasing negative impacts Governments will be making policies that mitigate their impacts as and when the occur. What is not known is whether they will have the political support form the worlds populations to make sufficient progress to halt the impact of the Anthropogenic impacts of climate change
