In my last post I discussed cattle ranching and the large scale deforestation it has been associated with. After reviewing the literature, I believe it is clearly apparent that these practises are posing a great threat to our global environment, and are by far, the main threat to tropical rainforests.
Some of the impacts of deforestation have already discussed within this blog, for example: soil/land degradation and water pollution. These are problems ubiquitous with cattle ranching. Nevertheless, there are some impacts that are magnified due to the association with rainforests - and these are what I want to discuss.
Green House Emissions
The WWF estimate that cattle ranching alone is accountable for the release of 340 million tons of carbon to the atmosphere per year, which is the equivalent to 3.4% of total global emissions. With an area the size of india being cleared over the last 25 years (approximately 13.2 million ha per year!!) it is easy to see that this is rivalling even the emissions from burning fossil fuels in cars!
This investigation also concluded that total emissions related to the Amazon ranged from 499 to 775 Mt CO2eq. I think this study is a commendable effort in trying to calculate the emission figures but the range of results suggests a large margin of error.
Furthermore, an investigation into increased deforestation fire activity in the Amazon conducted by Morton et al. in 2008 concluded no uniform relationship between the presence of fires and detections in CO2, this does not however state that burning the Amazon has no impact on CO2 levels, but rather indicates a complex feedback process that govern the associated GHG output. This is a spectacularly difficult area of investigation to negotiate and deliver a precise result.
There are further, secondary sources of emission that I believe also need to be taken into account. For example, the paper reveals that emissions from producing the energy for transportation and refrigeration of the meat is not considered - but in reality this surely should be a factor, considering these outputs would not be required given the absence of cattle in the first place?
In addition a paper by Cederberg et al. in 2011 explained that the carbon footprint of beef produced on newly deforested land is estimated at more than 700 kg CO2eq per kg carcass weight because of the loss of the CO2 intake by the plant life, amplifying the carbon footprint considerably.
Fire Clearing
During the dry season, Brazil often makes news headlines across the globe because of raging fires, a practice of agricultural management for opening rudimentary subsistence plantations (slash-and-burn agriculture) and cattle pastures (FAO).
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| Source: Sustainable works |
In the Brazilian Amazon, this is an especially dangerous procedure. Fires can easily spread into forests adjacent to the treated agricultural land.
Moreover, between 2000 and 2002, forest hotspots almost tripled from 16,000 to almost 42,000 per year (Barreto et al. 2005). Additionally it has been calculated that fires associated with deforestation contributed 67 Tg C/yr to the earths atmosphere. (17 and 50 Tg C/yr from conversion to cropland and pasture, respectively) while conversion of existing cattle pasture to cropland contributed 17 Tg C/yr and the maintenance of pastures; 6 Tg C/yr (DeFries et al. 2008). Which relates back to the larger carbon footprint of beef on newly cleared land previously discussed.
So in conclusion, these two factors are considerably exacerbated due to their location in the rainforest and pose an unparalleled threat to the biome, a fantastic article addressing the same issues can be found here which I highly recommend reading. But what is being done and what is the ecological response?
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| Source: The Independent |
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