Monday, February 7, 2011

Drought in the Amazon: Scary Stuff!


Here is a story that relates to many of the ecology case studies you are all working on.

Two major droughts in Brazil's Amazon region in the last six years threaten to undermine its role as the planet's most important carbon sink and a vital brake on climate change, according to new research.

Scientists from Brazil and the UK concluded that last year's Amazonian drought was more widespread and damaging than in 2005, which at the time was thought to be a "once in a century" event.

The Amazon River fell to its lowest level in decades, with many of its tributaries such as the Rio Negro completely drying up in some area. With tens of thousands of people dependent in the waterways for their survival, a state of emergency was declared in a number of towns in the region.

The report, published in the journal Science, calculated that the carbon impact of the 2010 drought may eventually exceed the 5 billion tonnes of CO2 released following the 2005 event. This compares to the estimated 5.4 billion tonnes of CO2 emitted through fossil fuel use in the United States in 2009.

Tropical rainforests such as the Amazon act as a natural buffer to man-made emissions by absorbing huge amounts of carbon each year. However they become major emitters of CO2 during drought years.

"In a normal year we would see these remote rainforests being net absorbers of carbon dioxide from the atmosphere," the report's co-author Simon Lewis, from the University of Leeds, told CNN.

"And a drought will kill some of those trees, and over time these trees will rot down and release carbon dioxide into the atmosphere.

"So over the next few years we'll see billions of tonnes of carbon dioxide going into the atmosphere from these rotting trees that were killed during the 2010 drought.

"That's enough to offset the carbon absorption, so that the rainforest becomes carbon neutral."

The research team, made up of scientists from the Universities of Leeds and Sheffield in the UK and the Instituto de Pesquisa Ambiental da Amazonia (IPAM) in Brazil, compared satellite data showing rainfall across the 5.3 million square kilometers of the Amazon Basin with information about how individual trees responded since the 2005 drought.

"We knew how many trees had died in 2005," said Lewis. "So we could use that relationship between tree deaths and the drought intensity from 2005 to estimate the impact of the 2010 drought."

Lewis warned more research was needed into the relationship between the droughts and climate change, despite some global climate models suggesting Amazon droughts will become more frequent in future as a direct result of greenhouse gas emissions.

He said: "We could see an increase in the severity and the number of these droughts, which could lead into a vicious cycle: droughts, then the forests releasing carbon reinforcing those droughts.

"At the present time we don't know whether these two droughts are just associated with natural climatic variability. If so, then we may go back to a situation of not seeing these droughts. It may just be an unusual decade."

But in any case Lewis believes current emissions pathways "risk playing Russian roulette with the world's largest rainforest."

14 comments:

Jordan Trafton said...

I'm not sure if anything can be done, but I hope things get better.

If not, we could always dump iron into the ocean to get rid of the carbon.

Casey's hypothesis: to make sure no bad effects happen, we need to test iron fertilization. Therefore, we should grow phytoplankton in a case and have them absorb radioactive carbon. The, we should kill them and dump them in the ocean :)

Micha said...

obviously this is a serious problem. but, could humans planting trees to replace the ones that died in the drought serve as carbon sinks thereby absorbing the CO2 going into the atmosphere from the rotting dead trees? The logging happening in the amazon is also contributing to this problem right? the floods are negatively affecting the native populations so i think we should educate the native population about the harm they are causing by cutting down the rain forest for agriculture. but in reality the whole world needs to end out destructive ways because that is really the only longterm solution.

Abbie Harlow said...

We should definitely start planting A LOT of trees to counteract all the trees that are dying because of this drought. That would help with climate change, I think, but obviously it won't completely cure the problem on its own; everyone on the planet needs to cut down on how much energy they use, otherwise we're not going to get very far very fast.

Oliver Meister said...

You know you're screwed when your rainforests are carbon neutral...

but I think planting more trees and stopping deforestation, both by natives and outside corporations who want to use for beef farming would help reduce the hazards of this situation.

And Jordan is entirely right, dumping iron into the ocean would hella help. Maybe even put some in the Amazon, closer to the wound.

Nathan said...

Lewis says that scientists aren't sure whether the change is simply due to "natural climatic variability," rather than man-made climate change due to excessive carbon emissions. However, the first 2005 drought was considered a "once in a century event." These droughts are clearly very rare events, and would be unlikely to occur twice within a mere five years under natural conditions. Using only what is written in the article as evidence, I would guess that scientists are pretty sure the droughts are due to man-made climate change, and Lewis is avoiding a potentially inflammatory declaration of that fact.

Planting trees in the drought region would not help the situation, because they would have no water to grow. Planting would have to wait until the region recovered, or be done somewhere else in the world.

Casey said...

Like Jordan, I am not sure whether anything can be done. According to that guy who came to our school last week, we are only witnessing the effects of greenhouse gases from the '50s. This makes it seem like there are already enough greenhouse gases in the atmosphere to sustain global warming for a long time. However, Jordan's solution of dumping a ton of iron into the ocean might not be good. This adds extra degrees of complexity to the problem, making it even harder to predict what might happen next.

Lex said...

if these droughts were caused by people, it's obviously a huge problem. i think that people really should be more careful about the energy they carelessly waste, and try to save as much energy as they can. also, with that much CO2, people should really try not to use deforestation in so many places to treat there current problems, like lack of land or wood, and think about the future consequences they could be causing by letting the CO2 levels increase so much. we should try to plant more trees and conserve energy and try to be aware of climate change.

Joel said...

I kind of agree with Ollie - it does seem like we may not be in the best shape because rainforests, a main absorber of carbon, are dying in the status quo. The problem is that there will always be an environmental effects to warming, and that we have to make the best of it. Planting trees would help too, and it's especially something that we could do close to home. Another way would be too try to restore a few natural rainforest habitats.

I guess I'm kind of ranting at this, but it isn't too great.

Hey, if all else fails, we could try to dump iron (despite the potential side effects).

Sormeh Yazdi said...

This article was unsettling. Although man-made climate change is more likely to be the cause of these very rare droughts, it's hard to say if we can do anything to prevent others from happening. Planting new trees in the area will not help because with the drought conditions they will simply end up dying and emitting more carbon into the atmosphere. I also believe that the best way to help right now would be to educate as many people as possible about the ramifications of deforestation. This might lead people to alter their current actions, and might encourage others--in other non-drought regions-- to plant more trees and find better ways to save energy.

Alex said...

I just want to ask, what happens if we plant more new trees, but in another five years, another drought comes along? Will these trees end up going to waste, and not even growing to their full size? I think we should really focus on carbon emissions from fossil fuels and getting away from them. Maintaining the amazon is extremely important, but based on recent events, we cannot be so reliant on it to reduce carbon emissions.

Emma V-B said...

I think that this article just goes to show exactly how scary climate change can be. If things that are thought to be “once in a century” events are happening twice a decade, there’s obviously something wrong! Before, I had never really thought about what happened to the CO2 after the trees died. If it’s all just released back into the atmosphere, then it’s our responsibility as humans to not just stop deforestation (cutting down trees= dead trees), but also to reverse the effects of all the deforestation that has been done in the past by planting lots of new trees. The only problem with that, however, is that it’s often difficult to go back and plant the much-needed trees in such a dry, droughty area. It seems to be that it’s pretty obvious that the two droughts are not “just associated with natural climatic variability.” If this were the case, then why have things like this not been happening a lot more frequently? I find it frightening that even some scientists, like Lewis, don’t seem to be taking the situation seriously enough, and are assuming that it could just be “an unusual decade.” Even if it is just a fluke period of time, we won’t know what effect the actions we take now could have later on, so it’s necessary to take steps forward to not only save the world’s largest rainforest, but also to reverse global warming. It seems like Lewis and other scientists aren’t willing to “[play] Russian roulette” and take a gamble—but they need to realize that it’s important to take risks if you want the situation to get better. Hopefully if word gets out about both of these catastrophic droughts, people—whether they’re scientists or not—will begin doing all that they can to stop carbon emissions before it gets so bad that even the rainforest is carbon neutral.

Matt Shachat said...

I think that if our rainforests are becoming carbon neutral, then we need to immediately find a way out of the situation we are in. This reinforces the sense of urgency that needs to be applied to this issue. Some way to reduce CO2 emissions that is drought-independent should be researched and cleared to be used worldwide. Stricter logging laws and getting to be independent from fossil fuels and the logging industry might help us short term, but all in all we need a long term solution to be implemented soon to save our planet from falling apart.

Laura M :) said...

I think it is clear that Lewis is being overly optimistic when he said "This may just be an unusual decade." If the 2005 drought was considered to be a "once in a century event" then it is clear that the reoccurrence of a worser extent of the drought in 2010 is a serious problem and that measures need to be taken immediately to counter-act it.

We need to take measures to plant more trees and reduce our own carbon emissions. Obviously we'd need to take into account that now we would need more trees to not only absorb our own CO2 emissions but also those of the rotting trees. Then in theory, we would be able to counteract the problem and start a "reversal avalanche." As more trees were planted, more CO2 would be absorbed, of our own emissions as well as those of the rotting trees, and hopefully this, combined with our own reduced carbon emissions, would at least stop the continuation of these droughts, and hopefully contribute to a reversal of the effects of the droughts.

Sarah said...

"But in any case Lewis believes current emissions pathways "risk playing Russian roulette with the world's largest rainforest.""

I find this comment particularly disturbing. To think that we play games with our environment is frightening to me. People in power need to take charge and start taking the question seriously, otherwise no one will. This is no to say that action doesn't need to be taken from a local standpoint either. I think whats most important is that everyone does something to take a stand.

also, I really have to agree with Abbie Harlow. I think planting trees natural to that environment is key to solving the issue. At the same time though, we need to think of some kind of governemntal legistlation that stops the trees from just being chopped down all over again.
those are my thoughts.
Sachs