impact of climate change on soil /land management?

Answer 1

Depending on the biome being studied CO2 can add carbon to the soil (particularly grasslands). This is not true in all biomes though. Present understanding has far northern soils losing carbon due to increased respiration. The total global impact of warming on the soil carbon pool is not well understood (1,2) (despite what some may state). But there was a net loss of carbon from soils during the European heatwave of the summer of 2003 (3).

Another issue that can limit how much more carbon is absorbed by soils in a warming world is nitrogen availability. Recent findings show that plant uptake of added CO2 is limited by the amount of nitrogen avaialable (4).

Answer 2

Shifting weather patterns mean some areas receive less rainfall; the ground becomes barren and unable to sustain crops. In many parts of the world the layer of topsoil is both very thin and very poor. The dry, dusty soil is readily blown away and the area becomes desert. African and Asian countries are particularly hard hit

For the reasons mentioned above there will be a major impact on agriculture. Rising sea levels will also impact resulting in the loss of large areas of agricultural land, the consequences of which will be population migration, famine and / or the need to import food from elsewhere. Again, it will be the African and Asian countries that are hardest hit with crop production falling by up to a third

Global warming can be a doubled edged sword. It has already resulted in the melting of a million square kilometres of Siberian permafrost, an area four times the size of the UK and covering the world’s largest peat bog. The melting has created land suitable for crops but at the same time has causing billions of tons of methane gas to be released from the peat, which in turn contributes to further global warming. A further consequence is the loss of over 1,000 lakes but the creation of many new ones.

We may one day see crops being grown in Antarctica. Grass is now becoming established there for the first time in 10,000 years.

Desertification is another problem, millions of people have already lost their lands as millions of square kilometres of agricultural land become desert. A further 50 million people are expected to be displaced within the next 10 years.

One very interesting area, about which I know very little so won't comment, is permaculture. Have a look at some of the links that Belladonna included in her question http://answers.yahoo.com/question/index;_ylt=ArjoFY0J6dBACq9PixdKGg7ty6IX?qid=20070620061231AA6HJ7k and also have a look at some of Byderule's answers http://answers.yahoo.com/my/qa/index;_ylt=ArrRNoePu.SomeZxh0teaozsy6IX?link=answer&more=y&show=AA10740247


The Times - Grass flourishes in warmer Antarctic
http://www.timesonline.co.uk/tol/news/uk/article405824.ece
Wikipedia - Desertification
http://en.wikipedia.org/wiki/Desertification
BBC News - Desertification
http://news.bbc.co.uk/1/hi/world/africa/6247802.stm
Related articles from The Guardian
http://www.guardian.co.uk/climatechange/story/0,12374,1517935,00.html
http://www.guardian.co.uk/climatechange/story/0,12374,1546824,00.html
http://www.guardian.co.uk/international/story/0,,1503170,00.html

Answer 3

Needs and problems will vary from place to place. Certainly there will be more wind-borne erosion in many places as lands become drier. As irrigation increases in marginal agricultural lands, the accumulation of salts and other toxins in the soil will reduce productivity and render some lands unfit for agriculture. Ranges for wild plants and crops will shift as temperatures rise and rainfall patterns change. Increased groundwater depletion will lead to subsidence and loss of some arable lands. On a larger scale, the melting of glaciers and ice caps will lead to seasonal drying up of some major perennial rivers, causing increased soil drying and dust storms in those river basins, especially in Africa and South Asia. Loss of ice on the Tibetan plateau will weaken regional temperature differentials, leading to disruptions in the monsoon and major crop losses in East and South Asia.

Answer 4

CO2 and warm air help the plants to become better at sequestering CO2 from the air and converting it to oxygen. It has been discovered that the plants actually are more efficient at it and work longer hours due to the increase in CO2. They store the extra carbon in their tissue and the ground and then release the oxygen.

Answer 5

As our planet warms up ,( as well as those in our solar system
as has been observed of late by the shrinkage of ice caps)
we will increasingly see more drought conditions and severe
weather excesses globally as well as regionally. ..
There can be little doubt that the western states will have
a BIG problem on their agenda regarding water usage and
availability.....