Posted on 05/07/2008 3:58:34 PM PDT by blam
Amazon doomed by too much clean air
Last Updated: 12:01am BST 07/05/2008
The lungs of the planet - the Amazon - could be wiped out within half a century as a result of too much clean air, writes Roger Highfield.
The vast rainforest, so crucial to the Earth's climate, is coming under threat from attempts to curb the pollution that causes acid rain, warn UK and Brazilian climate scientists.
The Amazon rainforest is threatened by drought
Their new study in Nature reports a link between reducing sulphur dioxide emissions from burning coal and increasing sea surface temperatures in the tropical north Atlantic, resulting in a heightened risk of drought in the Amazon rainforest.
The link was found by a team from the University of Exeter, Centre for Ecology and Hydrology, Met Office Hadley Centre and Brazilian National Institute for Space Studies.
A 2005 drought caused widespread devastation across the Amazon basin and the team estimates that by 2025 a drought on this scale could happen every other year and by 2060 a drought could occur in nine out of every ten years.
Lead author Prof Peter Cox of the University of Exeter says: "In our model the forest is in trouble by the middle of this century under a business as usual scenario (where economic growth continues to lead to increasing carbon dioxide emissions)".
As for when they could disappear, "2060 isn’t a bad guess," he says.
In turn the die back would accelerate the release of carbon and causing more climate change.
The team used a sophisticated computer model of the climate developed at the Met Office's Hadley Centre in Exeter to simulate 21st century climate change.
The drying of the Amazon is caused by a combination of increasing greenhouse gases and efforts to remove sulphate aerosol particles arising from the burning of coal in power stations.
Emissions of the particles in the 1970s and 1980s partially reduced global warming by reflecting sunlight and making clouds brighter. This pall of pollution has dominated in the northern hemisphere and has acted to limit warming in the tropical north Atlantic, keeping the Amazon wetter than it would otherwise be.
By incorporating the effects of aerosols into their computer model, the team is able to reproduce the observed variations in this temperature gradient over the past century.
By projecting these trends into the future they found that the trend to cut sulphur emissions in North America and Europe to curb acid rain, which has harmful effects on plants, aquatic life and buildings, will see tropical rain-bands move northwards as the north Atlantic warms, resulting in a sharp increase in the risk of Amazonian drought, like that experienced in 2005.
"These findings are another reminder of the complex nature of environmental change," says Prof Cox.
"To improve air quality and safeguard public health, we must continue to reduce aerosol pollution, but our study suggests that this needs to be accompanied by urgent reductions in carbon dioxide emissions to minimize the risk of Amazon forest dieback."
The Amazon rainforest contains about one tenth of the total carbon stored in land ecosystems and recycles a large fraction of the rainfall that falls upon it. So any major change to its vegetation, brought about by events like drought, has worldwide repercussions.
Prof Cox adds: "Rather ironically, one of the best ways to get started on reducing global carbon dioxide emissions is to reduce the rate of direct deforestation in Amazonia."
Dr Matthew Collins, of the Hadley Centre, coauthor, says: "The rainforest is under many pressures. Direct deforestation is the most obvious immediate threat, but climate change is also a big issue for Amazonia. We have to deal with both if we want to safeguard the forest."
Co-author Dr Carlos Nobre of the Brazilian Institute for Space Research adds: "Global warming,deforestation and increased forest fires are all acting in synergy to reduce the resilience of the Amazonian forests".
However, there is one important caveat to today's work. The predictions are made by the Hadley computer model and not all of the handful of global climate models in use around the planet agree on the degree and effects of climate change over time scales of several decades.
Prof Cox comments: "The Hadley model produces a more extreme drying in the Amazon than other models. However, our study suggests that it is also amongst the most realistic models in terms of its simulation of the Amazon climate."
This research was funded by the Natural Environment Research Council, the UK Department for Environment, Food and Rural Affairs, and the Brazilian Research Council.
too much clean air????.....don't tell algore,that will disprove his entire arguement about everything...wait....we already did that hahaha
Clean air and limited warming... argh, I’m sooo confused.
1. Evidence of nuclear war in atmosphere ...
and
2. Evidence of global warming
What’s new? I remember being taught that is we didn’t stop the clear cutting of the Rain Forest across the world, in particular the Amazon, we were going to regret it.
Well, it looks like we already are. The more we destroy the earth and have the earth absorbing the heat instead of it radiating back into the atmosphere, the more we are going to see storms like the tornadoes and hurricanes in the past years.
It’s only logical.
A new battle cry: “Remember the Amozon.....”
So we humans OVERCORRECTED! Just as we are doing with GLOWBULL WARMING! We are gonna freeze! Overcorrecting is gonna freeze us out! LOL Where is Al Gore in this milder cooler nicer than ever spring!?!?!?! LOL
My daughter is a geologist, unlike Al Gore, whom I think got a law degree... She has actually studied the climate of the earth over the millions of years... she says the earth is SELF HEALING!
I think when humans try to FIX things, we just mess things up. Calling All Gorey Where was he when Denver had a blizzard last week that closed I 70???? ha ha ha he is so stupid, except that he is collecting all those Carbon Credit$!
The earth was here before us and made it just fine through all the past cooling and warming stages! It is all just a normal cycle, and the Sahara was once ocean!
/s
Doomed if we do.
Doomed of we don’t.
Oh my head hurts. Jeez.
“The lungs of the planet - the Amazon “
Actually, the Amazon rain forest is a net user of oxygen, according to Patrick Moore, and is over 90% intact.
Raise your hand, though if you thought this was going to be about the online bookseller.
I was going to call this bull manure, but that would require the release of methane.
The mind boggles...
If this clown wants to “safegaurd the forest” then he should buy it first.
Hope he’s sitting onbarrels of cash.
As a matter of fact, didn’t “Holywood” (so they think) put out a useless piece of drivel in the form of a cartoon called “Fern Gully” to scare/indoctrinate children into believing that the Amazon was sacred? Where will they worship when the “overcorrection” we’ve made, dries up?!
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