Yes Brazil you guessed right. Brazil has less than 3% of the worlds populations and 12% of the worlds freshwater resources (Watts, 2014). Nevertheless at the moment the central , south eastern region of Brazil and most dramatically in its largest and most economically important city Sau Paulo is suffering a water crisis, which is having devastating effects on agriculture, energy and domestic water supplies. It is very perplexing to me that the region in the world with the most freshwater reserves is still vulnerable to water scarcity so lets take a look at why this is:
So what I have found out is the underlying factor responsible for the water crisis is the worst drought Brazil has experienced in the last 80 years (Davies, November 2014).The drought began last austral summer ( December to February), when Sao Paulo state received about one third to half of its usual amount of rain during what should have been its wettest month. In the seven months since, rainfall has been about 40 % of normal (Plumer , October 2014). Some Brazilian scientists say the current drought is a result of a combination of global warming and deforestation.
Despite Brazil being recently congratulated on its efforts to reduce deforestation in the past two years deforestation all over Brazil has reached alarming proportions: 22 percent of the Amazon rainforest (an area larger than Portugal, Italy and Germany combined), 47 percent of the Cerrado in central Brazil, and 91.5 percent of the Atlantic forest that used to cover the entire length of the coastal area has now been wiped out.
forest clearance in the Amazon
The combination of global warming and deforestation, they say, is reducing the role of the Amazon rainforest as a giant “water pump,” releasing billions of litres of humidity from the trees into the air in the form of vapour which then circulate west and south, falling as rain to irrigate Brazil’s central and southern regions. In January and February of this year, when rain is usually abundant in central and southern Brazil, the flying rivers ( which is the term for the vapour clouds from the Amazon) failed to flow south, according to data from Brazil’s National Institute for Space Research (INPE) (Maddocks et al, November 2014). ![](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_uhTRH2UNPIyhx6MZZpUNC3PGeWiU55mvysV9oJyEnA09r4Qs8pdfUJlDTKr-T9iZSjptgPt-Rfzki3yXMMF263KlAXPvVFPJJQ125AcLZCqgNH0OOCq-xrzY2o9FWJh1YxAU9p-F1BVE-J5j4e25IAtgZLK-T_DJZh4gg3Rg=s0-d)
Flying rivers animation
However in an article I read recently, Marshall ( the writer) argues that the extreme drought in Sau Paulo is not the result of deforestation. He contests this for two reasons. Firstly he argues that the deforestation is insufficiently large to account for the drought levels. Although according to Nobre - Brazils top climate scientist -the role of the Amazon rainforest in producing rain has been underestimated (Rocha , September 2014 ). In a single day, the Amazon region evaporates 20 billion tonnes of vapour − more than the 17 million tonnes of water that the Amazon River discharges each day into the Atlantic.
Secondly Marshall argues that there is evidence which points to a natural southerly shift in the current year in the easterly winds coming ashore in Brazil from near the Amazon delta to the much drier coast of Bahia (Marshall , 2014).
However time for something which is not contestable and that is the current drought should not have brought such havoc to regions of Brazil seeing the very important fact that Brazil holds the largest freshwater reserves in the world. This could only be a fault of humans, boom boom boom. Its hindered ability to adapt was a result of a series of interconnected water management failures across the metropolitan areas.
As climate scientist Marcos Heil Costa told Nasa, '"It is now clear that our policies on management of water resources are unsustainable, no city in southeast Brazil seems prepared to handle a drought like this one. It is a mix of a lack of preparation for low levels of rain and a lack of environmental education in the population. Most people continue to use water as if we were in a normal year"(Plumer , October 2014).
Excellent post. Undoubtedly, there are multiple factors at work here - and it seems unlikely that the clearance of so much forest would not have at least a local effect on precipitation levels. Were you able to find any information from climate change models on predictions for the future? Are additional and more severe droughts expected for the region or might this be a rare occurrence?
ReplyDeleteVery interesting post !! Water scarcity is not only due to deforestation. There are several factors for instance those pointed by Marshall. However, we can't deny that, part of water scarcity is the the result of deforestation.
ReplyDeleteto answer your question Rob, yes there is projected to be more of these droughts in in Eastern Brazil therefore it is crucial they learn to adapt better to these dry spells
ReplyDelete