Stanhill ss

This post will discuss about a paper written by Stanhill and Cohen (2001). It talks about the possible causes and consequences of global dimming on agriculture. The paper is a very scientific one which focuses on the methods used in their research to determine the causes and effects.

Findings have shown that since global radiation provides the energy for the carbon assimilation of plant canopies and their water loss to the atmosphere, it can thus also determine the heat balance of agricultural surfaces. This means that global radiation, too, controls the temperatures of the major environmental factors controlling the development of crops and livestock and hence threatens food security.

This information is of particular importance because the ecosystem is temperature sensitive. A “10–20% decrease in solar radiation reaching the surface of the earth, if unaccompanied by other climatic changes, would probably have only a minor effect on crop yields and plant productivity” (Stanhill & Cohen, 2001). However, any further decrease by phenomenon like global dimming might be expected to decrease productivity of plants.

Since aerosols are linked to the formation of clouds and hence rain, it is vital in providing moisture. Crop productivity can be largely limited by water. This moisture limitation caused by decreases in solar radiation (i.e. global dimming) often occurs in in tropical latitudes and in the arid and semi-arid regions of other latitudes. However, in wet climates with low radiative heat load on the plants, any decrease in solar radiation is likely to be accompanied by a small decrease in productivity (Wang et al., 1994).

Such are the possible agricultural consequences of global dimming and we must keep in mind that everything in the ecosystem is linked one way or another. A small effect on the productivity of plants may not seem as a cause for concern but may generate a domino effect in future generations.

References

Stanhill, G., & Cohen, S. (2001). Global dimming: a review of the evidence for a widespread and significant reduction in global radiation with discussion of its probable causes and possible agricultural consequences. Agricultural And Forest Meteorology107(4), 255-278.

Wang, G.G., Qian, H., Klinka, K. (1994). Growth of Thuja plicata seedlings along a light gradient. Can. J. Bot. 72, 1749–1757.