Why does deforestation cause desertification

Social and Environmental Dimensions of Health. Desertification is generally viewed as an advanced stage of land degradation. In addition, human activities often contribute to the process. While people have managed fragile drylands successfully for millennia in many parts of the world, pressure upon the land is much greater today as roughly 2 billion people inhabit drylands around the world.

Human activities that contribute to desertification include the expansion and intensive use of agricultural lands, poor irrigation practices, deforestation, and overgrazing. Ecosystems start to look different as more drought tolerant shrubs invade what used to be grasslands and more bare soil is exposed.

Examples are many countries in East Africa — especially Somalia, Kenya and Ethiopia — where over half of the population are pastoralists relying on healthy grazing lands for their livelihoods. The UNCCD estimates that around 12m hectares of productive land are lost to desertification and drought each year. This is an area that could produce 20m tonnes of grain annually.

This has a considerable financial impact. Loss of livestock, reduced crop yields and declining food security are very visible human impacts of desertification, says Stringer:.

Another impact of desertification is an increase in sand and dust storms. Dust storms can have a huge impact on human health, contributing to respiratory disorders such as asthma and pneumonia, cardiovascular issues and skin irritations, as well as polluting open water sources. They can also play havoc with infrastructure, reducing the effectiveness of solar panels and wind turbines by covering them in dust, and causing disruption to roads, railways and airports.

Adding dust and sand into the atmosphere is also one of the ways that desertification itself can affect the climate, says Kimutai. Dust particles in the atmosphere can scatter incoming radiation from the sun, reducing warming locally at the surface, but increasing it in the air above. They can also affect the formation and lifetimes of clouds, potentially making rainfall less likely and thus reducing moisture in an already dry area. Soils are a very important store of carbon.

This process also makes nutrients in the soil available for plants to use as they grow. Soil erosion in Kenya. And typically, respiration declines with decreasing soil moisture to a point where microbial activity effectively stops. While this reduces the CO2 the microbes release, it also inhibits plant growth, which means the vegetation is taking up less CO2 from the atmosphere through photosynthesis.

Overall, dry soils are more likely to be net emitters of CO2. So as soils become more arid, they will tend to be less able to sequester carbon from the atmosphere, and thus will contribute to climate change. Other forms of degradation also generally release CO2 into the atmosphere, such as deforestation , overgrazing — by stripping the land of vegetation — and wildfires. But coming up with a robust global estimate for desertification is not straightforward, explains Kimutai:.

The multiplicity and complexity of the processes of desertification make its quantification even more difficult. Studies have used different methods based on different definitions. And identifying desertification is made harder because it tends to emerge relatively slowly, adds Michaelides:. By the time it is detected, it may be hard to halt or reverse. Status of desertification in arid regions of the world. Taken from Dregne, H. The GLASOD project was itself based on expert judgement, with more than soil and environmental scientists contributing to regional assessments that fed into its global map, which it published in It categorised the degradation into chemical red shading , wind yellow , physical purple or water blue.

Shading indicates type of degradation: chemical red , wind yellow , physical purple and water blue , with darker shading showing higher levels of degradation. Source: Oldeman, L.

As the report puts it:. A single global map of land degradation cannot satisfy all views or needs. The parts of the world with the most potential issues shown by orange and red shading — such as India, Pakistan, Zimbabwe and Mexico — are thus identified as particularly at risk from degradation. Share in Facebook. Whatsapp Whatsapp. What is desertification? Discover its causes and consequences The UN, which has been fighting desertification since , defines it as the process of land degradation in arid, semi-arid and dry sub-humid areas as a result of various climatic and human factors.

Discover its causes and consequences environmental sustainability society climate change The UN, which has been fighting desertification since , defines it as the process of land degradation in arid, semi-arid and dry sub-humid areas as a result of various climatic and human factors.

Carousel of images and videos. Desertification and desertisation: differences Although they are often used interchangeably, the difference lies in the human influence on the process.

In this sense, some of the keys that can help to avoid desertification are: Promote coordinated land-use planning, including the management of water resources, livestock and agricultural activities.

Preserve vegetation cover, which plays a key role in protecting the soil from wind and water erosion, by building barriers and stabilising dunes. Promote climate change education to raise awareness, in particular by showing the consequences of desertification and ways to prevent it.

Focus on organic farming and sustainable practices, such as cover crops or rotational crops, which prevent soil erosion and drought. Commit to reforestation to regenerate vegetation cover, reactivate moisture circulation and generate biodiversity. The time for action is running out as the environmental damage rendered by deforestation and desertification expands, threatening new areas and new societies, while countermeasures tend to be long term and time consuming.

The cost of countermeasures is escalating from year to year because the area affected is growing, the degree of damage is growing, and world prices of rehabilitative measures are rising. Off-site and social costs too continue to increase. Other environmental and economic problems are likely to become serious, tending to distract the attention of international funding agencies to other issues e. However, if the process of desertification and deforestation is not arrested soon, the world shortage of food will increase dramatically.

Past experiences show that the success of programmes to combat desertification and deforestation will depend on the institutional arrangements, the dissemination of information, the creation of awareness, the development of assessment methodology, and adaptive research. Funding and implementing agencies, both national and international, must give priority to programmes for combating desertification and countering deforestation, both nationally and internationally.

The necessary assistance - in cash as well as in kind - will have to be provided to developing countries affected by these hazards. Any countermeasures will have to be fully integrated into programmes of socio-economic development, instead of being considered only as rehabilitation measures, and the affected populations will have to be fully involved in the planning and implementation of these programmes. Ahmad, Y. Desertification: Financial Support for the Biosphere.

West Hartford, Conn. Barrow, C. Cambridge: Cambridge University Press. Gadgil, M. Government of India. State of Forest Report, Forest Survey of India, Dehradun. Kemp, D. London: Routledge. Maheshwari, J. Reining, P. Handbook on Desertification Indicators. Washington, D. Tolba, M. El-Kholy, et al. The World Environment Two Decades of Challenge. Tucker, C. Dregne, and W.

Agenda Nairobi: UNEP. Winpenny, J. Development Research: The Environmental Challenge. Boulder, Colo. Wood, W. Tropical Deforestation. Contents - Previous - Next. Change in population biological parameters demographic evidence, migration statistics, public health information. At Lake Baringo, an area of , ha, the annual rate of land degradation desertification between and was 0. At Marsabit, an area of 1. In the three localities of Nara, Mordiah, and Yonfolia, with a total area of some , ha, the average annual rate of loss during the past years has been of the order of 0.

An annual rate of land degradation of 0. The country's average annual rate of abandonment of cultivated land owing to soil degradation increased from 0.