Sue Branford and Maurício Torres (NewScientist 7 March 2015) in “Dambusters” (paywall) cover the latest events in the Amazon Basin. Key information:
According to official satellite data, 22 per cent of the forest has been felled. But this is an underestimate as it fails to account for selective logging, which the satellite images don’t detect. After several years of marked declines in forest clearance, which won Brazil international plaudits, the level of deforestation has risen again.
As we all should have learned in school, there is a cycle of evaporation -> rain -> evaporation called the water cycle. In the Amazon the forest is a key part of this cycle:
While this may be a result of natural climate variability, Antonio Nobre, a senior researcher at Brazil’s National Institute for Space Research in São José dos Campos, says that the disruption is linked to deforestation. Recent research has shown that Amazon vegetation, particularly large trees, play a central role in maintaining the hydrological cycle. “In a single day a large tree in the rainforest can pump over 1000 litres of moisture from the soil into the atmosphere. If this is scaled up for the whole forest, it means the Amazon forest transpires 20 billion tonnes of water a day,” he says. Cut down the forest and you destroy the flying rivers.
So do trees make evaporation more efficient? That’s not clear in the article. The “flying river” is a nickname coined by a Brazilian scientist for the clouds formed from this evaporation that delivers rain to the south. But:
São Paulo, the industrial heartland of Brazil, is in the grip of the worst drought in living memory. The clouds from the Amazon that make the basin itself so wet and also deliver rain to the south of the country – dubbed “flying rivers
” by one Brazilian scientist – have failed to materialise.
And so on to the chase. The forest of the Amazon has been under attack for decades by slash and burn farmers, by miners, by developers – many of whom are operating illegally against Brazilian law, and all of whom are impacting local tribes, most in a negative manner as the forest they have existed in for centuries are now torn from them simply because they do not conform to modern notions of ownership – although the authors of the NewScientist article do cover the efforts of the Munduruku to take ownership of their bit of it. I think most folks would consider this to be … evil-doing. Not that the perpetrators see it that way, but then English colonialists hardly ever felt badly about killing American Indians, either. Here’s the thing: I think you can identify true “good guys” by the their activity patttern: they are cooperative. They have a sense of justice and they are aware that in order to achieve justice, they must work with each other, compromise.
The other side, what I find myself calling the bad guys tonight, cannot do that: they are motivated by unmoderated greed. Not that the good guys don’t have a spot of avariciousness in whatever they use for a soul, but it’s moderated and used for positive purposes. But if you look at criminal gangs, evil regimes, and even fiction: the bad guys tend to destroy each other. Working together tends to deny the greed which they feel. So:
if deforestation continues, the viability of the large dams may be compromised. Until recently most scientists thought that cutting down trees near dams increased the amount of water flowing into them. But a recent study by the Amazon Environmental Research Institute in San Francisco, California, came to a very different conclusion. It found that by 2050, when on present trends at least 40 per cent of Brazil’s Amazon forest will be gone, there will be a significant decline in river flows and energy generation (PNAS, vol 110, p 9601). This would make the reliability of the dams as an energy source highly questionable. …
Along with growing doubts from scientists, another factor is creating the perception that the authorities’ love affair with Amazon hydropower may be waning. Historically, one of the biggest drivers of dam-building has been a cosy relationship between big engineering companies and their political allies. “Energy planning in Brazil is not treated as a strategic issue but as a source of money for engineering companies and politicians,” says Felício Pontes, prosecutor for the Federal Public Ministry in Pará.
But many of the companies are now caught up in a massive corruption scandal involving bribery and money laundering by the state-owned oil company, Petrobrás. Investigators are examining the contracts for the Belo Monte dam, and a leading executive of one of the companies, Camargo Corrêa, which has been funding viability studies for the São Luís do Tapajós dam, has been arrested.
So, in order to build a dam, they have to destroy that which makes the dam economically viable, transgressing against folks who’ve lived in these areas for centuries; and in the process of deciding who gets to do what, the government and the companies indulge in corruption. As the scientists take in the new data and come to (always contingent) conclusions that this project will self-destruct, it is becoming less likely that hydroelectric power will be implemented on the Amazon.
