There are two major agricultural causes of climate change. These are methane and carbon emissions.
One of the foremost issues discussed in environmental circles nowadays is global climate change. Scientists are divided on the issue of climate change; whether there is really global warming or cooling and if man is a significant contributor. This may be the reason why instead of favoring one possibility to another, the term climate change became a compromise stand to define what is currently going on with the global climate. Climate change is a better term because it combines both possibilities.
Human influences to either direction require a thorough understanding and synthesis of scientific literature. Current global climate events appear to confirm that man, indeed, can cause global climate change. Apparently, more emissions of greenhouse gases like carbon dioxide and methane arising from human activities in quest of economic development, hurricanes become more damaging to lives and properties. The global climate seems unlike what it was before.
Agricultural Causes of Climate Change
Agricultural practices are among those culprits identified by scientists as responsible for the apparent global climate change scenario as evidenced by severe storms or typhoons, abnormal distribution of precipitation worldwide, melting of ice caps, among others. While agriculture is an indispensable activity to sustain modern human society since man decided to abandon nomadic approaches in producing his food, it has some negative externalities that impact on global climate condition. Externalities are by-products of activities that affect the well-being of people or damage the environment.
Here are two externalities associated with current agricultural practices that are associated with global climate change:
1. Methane emissions.
Animal husbandry, rice cultivation and biomass burning are among those agricultural practices that contribute methane (CH4) to the atmosphere. In animal husbandry, enteric fermentation takes place.
Enteric fermentation is fermentation that takes place in ruminant animals like cows and carabaos. Rice production account for at least 30% of the global annual emission of methane in the atmosphere. As the population keeps on increasing, global demand for just rice alone will mean intensified global fertilizer application. Ammonium-based fertilizers can enhance methane emission (Bodelier et al., 2000). Biomass burning is the burning of vegetation for land clearing prior to land use. It also includes those instances where fires can be induced by lightning. Most of biomass burning is due to man. Scientists estimate this at 90% (Earth Observatory, 2010).
2. Carbon emissions.
Carbon emissions from extensive forest fires contribute to the pool of greenhouse gases in the atmosphere. It is common practice in tropical countries to burn the vegetation before planting. Indigenous peoples, and even migrating farmers who settle in unexplored lands, practice slash-and-burn farming. Although the indigenous peoples burn only a small portion of the forest in order to produce food enough for subsistence, the latter burn forests mainly to produce more than is needed. Sometimes, burning gets out of control. Thus, extensive forest fires occur.
Source: Earth Observatory (2010)
Plants serve as natural storage areas for carbon dioxide through the process of photosynthesis. When forests are burned, hundreds of years of stored carbon dioxide will be liberated into the atmosphere in just a matter of hours. If vegetation is not replaced, carbon in the atmosphere will not be brought back as biomass in plants (Earth Observatory, 2010).
Fossil-fueled farm machineries also add to the amount of carbon emitted globally. This is especially true in countries which extensively use agricultural machines in preparing land for planting, weeding, harvesting, winnowing, among others.
Therefore, government policies aimed towards regulating or minimizing the effect of the two major agricultural causes of global climate change must be formulated and implemented. Man needs to ensure food security, but balance must be achieved such that agricultural production processes and technologies do not impact negatively to the environment.
Earth Observatory, 2010. Biomass burning. Retrieved on March 23, 2010 at http://earthobservatory.nasa.gov/Features/BiomassBurning/.
Paul L. E. Bodelier, P.L., Roslev, P., and P. Frenzel, 2000. Stimulation by ammonium-based fertilizers of methane oxidation in soil around rice roots. Retrieved on March 23, 2010 at http://www.nature.com/nature/journal/v403/n6768/abs/403421a0.html.
United States Environmental Protection Agency, 2010. Methane: sources and emissions. Retrieved on March 23, 2010 at http://epa.gov/methane/sources.html.
8 Doable Agricultural Practices to Mitigate the Impacts of Global Climate Change
5 Agricultural Consequences of Global Climate Change
©Patrick A. Regoniel 23 March 2010 Two Major Agricultural Causes of Global Climate Change