Potential Effects of Climate Change in the UK
Climate change has potential risks for the UK. Most critical of these risks is the frequency and changes in extreme climatic conditions such as hot spells, drought and storms. It is likely that the occurrence of hot, dry summers will increase, while the chance of extreme cold winters will decrease. Average temperature is expected to increase by between 0.9 and 2.4°C by 2050, whilst precipition is expected to increase in most areas, particularly in winter and in the northwest of Britain. At this stage in the scientific understanding of the effects of climate change, it is difficult to speculate on the effect of climate change for other extremes such as the occurrence of storms.
Higher temperatures, which may result from climate change, would reduce the water holding capacity of soils increasing the likelihood of soil moisture deficits. These changes would have a major effect on the types of crops, trees or other vegetation that the soils can support. The stability of building foundations and other structures, especially in central, eastern and southern England, where clay soils with large shrink-swell potential are abundant, would be affected if summers became drier and winters wetter. The loss of organic matter due to changing climate would affect the stability of soil structure, ecological habitats nationally, and agricultural use in southern England. Currently poorly drained mineral soils could become drier and hence less of a problem, whereas, close to low-lying coastal areas, well-drained soils could become poorly drained. If the water table rose with the rising sea level, a change in soil processes would result. Soils affected by rising sea levels would become saline and unsuitable for the growing of crops.
Flora, Fauna & Landscape
Any sustained rise in mean surface temperature exceeding 1°C, with the associated extreme weather events and soil water deficits, would have marked effects on the UK flora and fauna. There may be significant movements of species northwards and to higher elevations. Predicted rates of climate change may be too great for many species, particularly trees, to adapt genetically. Many native species and communities would be adversely affected and may be lost to the UK, especially endangered species which occur in isolated damp, coastal or cool habitats. It is likely that there would be an increased invasion and spread of alien weeds, pests, diseases and viruses, some of which may be potentially harmful. Increased numbers of foreign species of invertebrates, birds and mammals may out-compete native species.
Climate changes are likely to have a substantial effect on plant growth, and by extension plant productivity. In general, higher temperatures would decrease the yields of cereal crops (such as wheat) although the yield of crops such as potatoes, sugar beet and forest trees would tend to increase. However, pests such as the Colorado beetle on potatoes and rhizomania on sugar beet, currently thought to be limited by temperature, could become more prevalent in the future. The length of the growing season for grasses and trees would increase by about 15 days per °C rise in mean surface temperature, an increase that could improve the viability of grassland, animal production and forestry in the uplands. If temperatures increase, there would be opportunities to introduce into the UK new tree species and crops, such as maize and sunflower, which are currently grown in warmer climes.
Increases in mean sea level, and the frequency and magnitude of storms, storm surges and waves would lead to an enhanced frequency of higher sea levels and coastal flooding. Currently, sea-level around the British coastline is expected to increase form between 12 and 67cm by the 2050s. A number of low-lying areas are particularly vulnerable to sea level rise including the coasts of East Anglia, Lancashire and the Yorkshire/Lincolnshire area, the Essex mudflats, the Thames estuary, parts of the north Wales coast, the Clyde/Forth estuaries and Belfast Lough. Flooding would result in damage to structures and short-term disruption to transport, manufacturing and the domestic sector. In addition, longer term damage to agricultural land, engineering structures such as buildings and coastal power stations, rail and road systems, would occur in some areas due to salt infiltration. Groundwater provides about 30% of the water supply in the UK. A rise in the water table associated with higher sea levels may increase the salination of groundwater over long periods, with consequent effects for water supplies.
Water resources would generally benefit from wetter winters, but warmer summers with longer growing seasons and increased evaporation would lead to greater pressures on water resources, especially in the south-east of the UK. Increased rainfall variability, even in a wetter climate, could lead to more droughts in any region in the UK. Higher temperatures would lead to increased demand for water and higher peak demands, requiring increased investment in water resources and infrastructure. An increase in temperature would increase demand for irrigation and abstraction from agriculture would compete with abstractions for piped water supply by other users.
Higher temperatures would have a pronounced effect on energy demand. Space heating needs would decrease substantially but increased demand for air conditioning may entail greater electricity use.
Manufacturing & Construction
Repeated annual droughts could adversely affect certain manufacturing industries requiring large amounts of process water, such as paper making, brewing, food industries and power generation and chemical industries. Although warmer winters would confer some benefits for construction productivity, increased winter rainfall would adversely affect building operations. However, the greatest negative impacts on construction are likely to arise from the combination of sea level rise and alterations in inland water hydrology.
Sensitivity to weather and climate change is high for all forms of transport. Snow and ice present a very difficult weather related problem for the transport sector. A reduction in the frequency, severity and duration of winter freeze would be likely under conditions associated with climate change and could be beneficial. However, any increase in the frequency of severe gale episodes could increase disruption to all transport sectors.
The insurance industry would be immediately affected by a shift in the risk of damaging weather events arising from climate change. If the risk of flooding increases due to sea level rise, this would expose the financial sector to the greatest potential losses (the value of the property protected by the Thames Barrier is estimated to be in the region of £10 to £20 billion). If climate change and sea level rise affect socio-economic activities, the appraisal of existing and new investment opportunities would also be affected, particularly in agriculture and for coastal regions. The role of insurance in protecting the most vulnerable areas or activities would also change.
Recreation & Tourism
UK tourism has an international dimension which is sensitive to any change in climate which alters the competitive balance of holiday destinations world-wide. If any changes to warmer, drier summer conditions occur, this could stimulate an overall increase in tourism in the UK. However, any significant increase in rainfall, wind speed or cloud cover could offset some of the general advantages expected from higher temperatures.