November 30, 2010
Source: Vancouver Sun
A fisherman stands at his floating house in Caapiranga, in the Amazonas state of northern Brazil, earlier this month. An intense months-long drought through November drained the mighty Negro river -- a tributary of the Amazon -- to its lowest since records began in 1902.
Photograph by: Ricardo Moraes, Reuters, Reuters
The river loops low past its bleached-white banks, where caimans bask in the fierce morning sun and stranded houseboats tilt precariously. Nearby sits a beached barge with its load of eight trucks and a crane. Its owners were caught out by the speed of the river's decline.
This is what it looks like when the world's greatest rainforest is thirsty. If climate scientists are right, parched Amazon scenes like this will become more common in the coming decades, possibly threatening the survival of the forest and accelerating global warming.
The environmental and economic consequences could be huge -- for Brazil, for South America, for the planet.
An intense months-long drought through November drained the mighty Negro river -- an Amazon tributary -- to its lowest since records began in 1902, drying up the network of water that is the lifeblood of Brazil's huge Amazonas state. More than 60,000 people went short of food and many lacked clean water as millions of dead fish contaminated rivers.
It was a once-in-a-century weather event. The weird thing is, it came just five years after another severe Amazon drought that meteorologists had described in the same way. Last year, massive floods in the region killed dozens and made hundreds of thousands homeless, fitting a pattern of more extreme weather that climate models forecast for this century.
Years like this add credence to predictions that, by the middle of this century, the forest will suffer "mega-droughts" lasting years, killing trees en masse.
That, in turn, would reduce rainfall over the remaining forest, creating a vicious cycle that would turn much of the Amazon into a savannah-like state by 2100. Ecologists and climatologists say there may come "a tipping point" after which the death of the forest becomes self-sustained by higher temperatures, dwindling rain levels and destructive fires.
The latest drought came as little surprise to Erli Perreira, a skinny 19-year-old who was fishing for his family's dinner in the shadow of the barge, which lay on a tributary of the Solimoes river about 97 kilometres from the central Amazon city of Manaus. The sun has been getting hotter for years, he said, making it impossible to work in the fields after mid-morning and causing his fish catch to plunge.
"Many things in the Bible are coming to pass," said Perreira, wearing a soaked Guns N' Roses T-shirt and holding a gasping fish in one hand. "At the end of times many things change, like the sun getting hotter."
Their predictions may be less biblical, but climate scientists and ecologists are worried, too. As leaders gather this month for a new round of global climate talks in Cancun, Mexico, the recent weather extremes have sent climate scientists around the world scrambling to study whether they represent a freak or a more sinister sign of climate change.
Rosie Fisher, a project scientist at the National Center for Atmospheric Research (NCAR) in Colorado, has always viewed apocalyptic Amazon scenarios with a dose of skepticism. Many of the complex models that seek to map future climate, including NCAR's own, show that Amazon rainfall may, in fact, change little over this century.
Shock and alarm
But she got a shock when she saw maps showing the paltry rainfall over the Amazon this year, less than half average annual levels. The drought of 2005 was severe, but maps showing water deficits over the region this year painted an even drier picture.
"The map that I'm looking at now looks like the extreme bit of my scenario, and it's happening right now. I'm genuinely quite alarmed by this," said Fisher, who specializes in the interactions between climate and forests.
Accounting for more than half of the world's remaining rainforest, the Amazon's trees are a vital global air conditioner, helping to keep the world cool by soaking up atmospheric carbon totalling about 2 billion tons each year. When they die or wither, as they did in large numbers during the 2005 drought, they become part of the global-warming problem by releasing carbon.
The 2005 drought released more greenhouse gases than the annual emissions of Europe and Japan, an international study found last year, showing how the forest can shift rapidly from carbon sink to source. If that study was right, this year's drought is likely to have released at least as much carbon.
The Amazon -- spanning nine countries and seen as the world's greatest cauldron of biodiversity -- is expected to be hotter by the end of the century than it has been since before the last ice age. Depending on greenhouse gas emissions, climatologists say a rise of 3 to 5 degrees Celsius is likely.
For the region's people, who still largely live off its land and water, that is likely to mean an ever tougher struggle to survive. Brazil's agriculture boom, which has seen it become one of the world's breadbaskets, would also be at risk.
The consequences for the forest's diversity of fauna and flora and for the fight against global warming could also be grave. A large-scale Amazon "dieback" is among a handful of potential events that could drastically intensify climate change, along with the melting of ice sheets in Greenland and Antarctica and the breakdown of the Gulf Stream ocean current. In some ways, it is the most worrying because of the speed it could occur and the huge amount of carbon it could pump into the atmosphere as trees die -- estimated at about 15 years' worth of human-caused emissions.
A dry new world
About 1,400 kilometres southeast of Manaus, the east of Brazil's Mato Grosso state may be an early indicator of what the worst case scenario could look like. Here the country's expanding cattle-and soy-farming frontier collides with the forest, often with fiery consequences.
This year's drought turned the region around the huge protected Xingu indigenous Indian park into a tinderbox. Fires, often set by small-time farmers to clear their land, raged through farmland and forest.
The number of fires in Mato Grosso -- which means thick forest -- surged to more than 36,700 so far this year, from 8,135 last year, razing cattle pasture, killing livestock and often jumping into the region's remaining pristine forest. A NASA satellite image from the period shows smoke blanketing the centre of South America.
Indigenous Indian farmers who used to plant their fields in August now do so in October or November because of the later rains. Among fields whose blackened fence posts betray the fires that raged here weeks earlier, chief Damiao Paridzane leaned on his hoe and spoke wistfully of a youth spent under trees and fruit before the "white man" made contact with his Xavante (Warrior) tribe.
Now, the 1,000 in his community live on a reserve east of the Xingu park that has been almost totally deforested and widely invaded by land-grabbers.
"If I was born today, I would be born weak because there isn't nature, there isn't forest or good air for us to breathe," said the 58-year-old. "The climate has worsened and will get hotter. If this cassava I'm planting doesn't get rain we will get thin because of these changes."
Farmers, loggers and land speculators have destroyed nearly a fifth of the original Amazon forest, but the rate of destruction has fallen dramatically in the past few years. About 6,993 square kilometres was lost in 2008-09, a more than 70-percent fall over five years, a dramatic change that the government says is largely a result of better monitoring and enforcement of laws.
But that is only part of the story in a region the size of western Europe and where Brazil's environmental agency has just six helicopters. The fall in deforestation also coincided with a slump in global commodity prices and a worldwide recession, suggesting that it could be a temporary lull.
Even if deforestation directly caused by human intervention were to fall to zero, the balance of evidence suggests that the forest is intensely vulnerable in a warming world.
As in 2005, climate scientists say this year's drought was probably caused by a warming of the North Atlantic Ocean that causes air over the Amazon to descend, hampering the formation of rain clouds. Some models show that trend intensifying as the planet warms.
Scary temperature rise
By far the scariest reading on the Amazon's future comes from the British Met Office's Hadley Centre, whose models show a disastrous rise in regional temperature of 8 degrees Celsius or more by the end of the century. Under that scenario, the forest retreats to a tiny fraction of its current size.
While the scientific jury may still be out on how more extreme weather will affect the forest, the region's inhabitants are already suffering the consequences. For the second time in five years, drought in Amazonas state, which is the size of Alaska, brought the surreal site of cars driving where people swam just weeks earlier. Some residents desperate for food scooped endangered manatees from shallow rivers.
Officials in Manacapuru, on the Solimoes river near Manaus, say recent extremes have prompted an influx of environmental migrants. "It's a consistency of extremes," said vice-mayor Joao Messias. "Our city here is literally full. It has filled up a lot after these big floods and droughts."
In the smaller town of Caapiranga, which was mostly cut off from boat transport by the drought, residents complained that many foods had doubled in price and that their cropland had yet to recover from the devastation caused by 2009's floods.
From his shack next to a dried-up lake, Manuel Ferreira de Matos, 57, squinted through battered spectacles at the distant water glistening like a mirage more than a kilometre away.
"By the time I get back home from the fields, I'm dying of thirst," said the father of seven.
"Before I could walk all day, no problem, but now I can't stand it -- it's like the sun got closer."