Climate change impact on soils

There can be many potential impacts of climate change on soils which can affect greatly their functions and their potential use. One of the likely effects of a warmer climate will be to change some of the habitats of the numerous organisms that live in the soil. The rate at which organisms can change to adjust to relatively rapid changes in soil conditions, particularly those of temperature and soil moisture, is not well known. Whereas humans and many animals may be able to adapt by moving location or making adjustments to lifestyles, in the case of soil biota too little is known about them to be able to answer this question. Yet they are vital in many aspects of agriculture and the biosphere in general.There are significant economic impacts of climate change on soils such as changes in land-use capability and changes in productivity.

The drier conditions, coupled with increasing frequency of torrential storms in some areas, will put more land at risk from erosion, desertification and salinisation. Many of the countries of Africa south of the Sahara and also Australia are predicted to become drier, and these already have major problems with soil erosion, desertification and salinisation. There will be an increased need for irrigation to grow crops in these areas, where already water supply is a problem. There is also more risk of loss of organic matter from the surface horizons of soils under a warmer climate. Since organic matter is such as important factor in nutrient provision to crops and other plants, to soil structure and drainage, and to waterholding capacity it can make crop production more difficult and can decrease the range of plants that can grow in a particular soil.

Farming will have to change in many parts of the world in response to the new climatic environment that develops. Generally it is likely to become more difficult to achieve reliable yields of crops as the temperature increases and certainly in cases where this is coupled with more droughty conditions then it is almost certain that we shall see a movement in the distribution areas of crops in line with the changing climatic environment. In Britain there is already talk of the areas of vineyards being extended as the temperature regime becomes more akin to that of Southern France and Spain. So there could be benefits as well as losses but the losses are likely to have a greater effect. It is much easier for agriculture to adjust to a new climate because humans can adjust to new conditions provided the conditions of the soil do not become too severe.There are, however, other risks to contend with. Low-lying land such as coastal plains will be faced with major risk from rising sea levels. Sea-level is predicted to rise by almost a metre globally in the next 100 years. This will put considerable amounts of land under water, leaving the land unavailable for agricultural use. Such coastal land is often fertile and important land economically. In the case of natural and semi-natural habitats nature will have to try to re-adjust. The important question is 'Will the rate of climate change be too rapid for these latter habitats to do so in some cases?'