A Deeper Dive into Deforestation: Part 2

Written by: Caroline Kim

November 14, 2021

In this final part of our discussion on Deforestation and the many factors that are influenced by it, rainfall, pastures, agriculture, and climate will be the central topics of concern. The Article Effects of tropical deforestation on climate and agriculture by Deborah Lawrence and Karen Vandescar guides us through this summary. From mesoscale models, it has been concluded that while temperature is a continuous issue, the decline of rainfall was minor in studies of Amazonian deforestation. In west African countries, it was also concluded that monsoon circulation provides more than 75% of the rainfall; thus, it is very sensitive to deforestation. Rainfall has shown a pattern of increasing downwind of deforestation and decreasing upwind in both Africa and the Amazon. Transitioning into the topic of Pastures, both small and medium spatial scales were observed. At small spatial scales, measurements of the atmosphere above forested and deforested land in the Amazon have indicated an increase in temperature and decrease in evapotranspiration. Medium spatial scales, on the other hand, show that there are fluctuations in the cloud cover that comes with deforestation; measurements in the tropics even show that rainfall is sensitive to these forest covers. However, they claim that, still, further work must be done to truly understand the effect of local climate factors including deforestation, atmospheric fluctuations, and sea surface temperatures.

The next aspect of deforestation to consider is its effect on agriculture; observations have shown correlations between tropical deforestation and water resources/crop productivity. Models have shown that large-scale changes in forests in a region could result in climatic impacts that limit the productivity of food in other regions. Changes in the mean yearly temperature and precipitation are also predicted to reduce the efficiency of the crop and affect where it can be grown. For example, the cold air deviations in South America affect coffee crops; these deviations are said to be likely to increase with the practice of deforestation. Deforestation has also been shown to influence diurnal temperature oscillation, and observations from the Amazon have shown the variability in pastures that in forests. Because of this possible variability, crops would need to not only increase their tolerance for a variety of temperatures (both cold and hot). Along with climate detriments, a decrease in rain can deprive the soil of its moisture and have overall extreme effects on agricultural systems. Lawrence and Vandescar’s main points are these: deforestation affects temperature/rainfall, which affects agriculture.

Citations:

Lawrence, Deborah, and Karen Vandecar. “Effects of Tropical Deforestation on Climate and Agriculture.” Nature Climate Change, vol. 5, no. 1, 2014, pp. 27–36., https://doi.org/10.1038/nclimate2430.