Probable effects of climate change
Greenhouse effect brings more precipitation and windstorms...
One of the most likely effects of global warming is the higher frequency of weather extremes, such as violent precipitation, windstorms and extreme temperatures, which will lead to a rise in both the number of loss occurrences and their impact. Global warming in general increases the air's capacity to absorb water vapour and hence the precipitation potential (torrential downpours). Milder winters also bring less snow and frost and more precipitation, thus aggravating the risk of floods due to increased discharges and ground saturation. Moreover, mild winter temperatures reduce the snow areas over which stable, cold high-pressure previously formed a barrier to the low-pressure systems coming in from the Atlantic, allowing gales to sweep across unchecked. There is as yet no conclusive proof of an actual increase in the frequency of storms, but such an outcome is considered probable. That winter precipitation amounts will increase is held to be inevitable, so that winter storms will become wetter and cause more losses.
...and warmer summers
Warmer, drier summers will bring more heatwaves and droughts. This will result in damage caused by wildland fires, and losses in sectors such as agriculture, inland shipping, and energy supply. Very high temperatures may also lead to structural damage caused by subsidence in areas with clay soils, a phenomenon already encountered in the UK. We will also increasingly have to expect the heat to have a negative effect on human health and cause a higher mortality rate among the elderly. The record temperatures of summer 2003, when there were some 35,000 deaths in Europe due to the heat, can be regarded as the pattern of things to come. At the same time, summer precipitation is also undergoing long-term changes. Whilst precipitation amounts overall are tending to diminish, events of a highly convective character — namely storms, which may be accompanied by hail and tornadoes — are expected to increase in intensity. Apart from the massive human and social impact, extreme weather events also cause particularly heavy financial losses, for which neither we ourselves nor the systems (e.g. the infrastructure) being geared to cope.
Other global consequences of the greenhouse effect
A further likely consequence is that the desert regions will expand. Drought conditions and the global water shortage are likely to escalate. Intensive cultivation of the land will shift away from the regions where it is practised today to new areas (e.g. from parts of the US to Canada). As the waters of the oceans warm up, the sea level will rise, contributing further to coastal erosion and corresponding property damage. We must also expect to see tropical cyclones of greater intensity.
Forest belts still intact at the present time are likely to suffer damage, reducing their capacity to store CO2 and further reinforcing the greenhouse effect. Essentially, we can expect to see ecosystems change, with unforeseeable consequences for food supply. We will also have to be ready to deal with new diseases and epidemics. However, it is also conceivable that positive effects will result from a higher CO2 content, one of which may be improvements in plant growth.
It does not look as if we will be able to halt the anthropogenic greenhouse effects in the next few decades. Even if all emissions were to cease immediately, the lifetimes of most greenhouse gases are such that their effects would continue to spread throughout the atmosphere for many years to come. In future, science and society will face the new challenges of exploiting opportunities for adjusting to the changes in our living conditions brought about by the greenhouse effect and avoiding a further increase in the anthropogenic greenhouse effect.