Reucing the impacts on soil

It is generally thought that it is now too late to significantly stop the proposed changes to the climate, certainly those predicted for the next 40-50 years. With the greenhouse gases already in the atmosphere and the difficulty of putting brakes on continuing emissions, particularly in the United States and many of the developing countries, it seems likely that the changes forecast for the next half a decade will occur. There is now some evidence of government appreciation of the scale of the problem developing with its associated widespread repercussions. The need for preventative measures is urgent, and some governments are beginning to drive industry to take measures to reduce the outputs of greenhouse gases. But the population continues to increase, requiring more industry, more vehicles, and more demands on the environment. For example, there has been, and is still planned to be, a huge increase in air traffic and movement, and as the population increases so will the need for vehicles. Both of these will be increasing contributors to greenhouse gases and climate change unless much cleaner technologies can be developed and put into practice swiftly.

What of the soil? What part can soil play? We have already seen how soils store more carbon than the whole of the atmosphere and all plant life combined. The importance of this, long appreciated by soil scientists, is now slowly being recognised more widely. Even so organic matter levels in soils have decreased worldwide as more and more land is taken into agriculture, particularly under arable forms of agriculture. Generally the more intensively that land has been used for agriculture, the more risk there has been of loss of organic matter. That loss of organic matter means that more carbon dioxide has been released to the atmosphere. Agriculture has been a significant contributor of carbon dioxide to the atmosphere as well as of nitrous oxides via the huge increase in fertiliser use in the developed world. Now there is a pressing need to practice forms of agriculture which retain as much of the organic matter in soils as possible and wherever possible actually increase the soil organic matter content. Throughout the developed world, many techniques are now being evaluated and tried in order to retain and increase amounts of the organic matter held in the soil. It is important that this is successful for the welfare of future generations

To look after soil quality and ensure that soils play an important role in addressing climate change, it will be important to adopt many of the recommended methods for organic carbon 'sequestration' (the capture and retention of carbon in the soil system). Some of these methods include: minimising the amount of tillage in crop preparation, managing nutrients carefully so as to avoid excesses, use of cover crops, agroforestry practices, regenerating forests where possible, careful management of organic soils so as to avoid shrinkage and oxidation, and more extensive use of energy crops to provide natural energy with the benefit also of needing less reliance on more polluting sources of energy. These methods will also increase the health and productivity of soils, making them more able to feed the growing world population while at the same time diminishing some of the risks of the widespread problems that climate change will cause if it is unchecked. These potential problems include migration of peoples, food insecurity, major losses of habitats. Set against this there will be some areas that will benefit from climate change but current predictions are that the negatives will far outweigh the positives.