Amazon rainforest recovering from its second 100-year drought in 5 years

By: Dr. Jeff Masters , 2:32 PM GMT on December 03, 2010

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Life-giving rains have returned over the past two months to Earth's greatest rainforest--the mighty Amazon--after it experienced its second 100-year drought in five years this year. The record drought began in April, during the usual start to the region's dry season, when rainfall less than 75% of average fell over much of the southern Amazon (Figure 2.) The drought continued through September, and by October, when the rainy season finally arrived, the largest northern tributary of the Amazon River--the Rio Negro--had dropped to thirteen feet (four meters) below its usual dry season level. This was its lowest level since record keeping began in 1902. The low water mark is all the more remarkable since the Rio Negro caused devastating flooding in 2009, when it hit an all-time record high, 53 ft (16 m) higher than the 2010 record low. The 2010 drought is similar in intensity and scope to the region's previous 100-year drought, which hit the Amazon in 2005, according to Brazil's National Institute of Space Research. Severe fires burned throughout the Amazon in both 2005 and 2010, leading to declarations of states of emergencies.


Figure 1. Hundreds of fires (red squares) generate thick smoke over a 1000 mile-wide region of the southern Amazon rain forest in this image taken by NASA's Aqua satellite on August 16, 2010. The Bolivian government declared a state of emergency in mid-August due to the out-of-control fires burning over much of the country. Image credit: NASA.

Causes of the great 2010 Amazon drought
During the 20th Century, drought was a frequent visitor to the Amazon, with significant droughts occurring an average of once every twelve years. These droughts typically occurred during El Niño years, when the unusually warm waters present along the Pacific coast of South America altered rainfall patterns. But 2010 was a La Niña year. The 100-year drought of 2005 occurred in an El Niño-neutral year. Subsequent analysis of the 2005 drought revealed that it was unlike previous El Niño-driven droughts, and instead was caused by record warm sea surface temperatures in the Atlantic (Phillips et al., 2009.) These warm ocean waters affected the southern 2/3 of the Amazon though reduced precipitation and higher than average temperatures. Very similar record Atlantic sea surface temperatures were observed in 2010, and likely were the dominant cause for the 2010 drought.


Figure 2. The great Amazon drought of 2010 began in April, when portions of the southern Amazon recorded precipitation amounts less than 75% of normal (brown colors). The drought spread northward and peaked during July and August, but drew to a close by November when the rainy season began. Image credit: NOAA Climate Prediction Center.

The importance of the Amazon to Earth's climate
We often hear about how important Arctic sea ice is for keeping Earth's climate cool, but the Amazon may be even more important. Photosynthesis in the world's largest rainforest takes about 2 billion tons of carbon dioxide out of the air each year. However, in 2005, the drought reversed this process. The Amazon emitted 3 billion tons of CO2 to the atmosphere, causing a net 5 billion ton increase in CO2 to the atmosphere--roughly equivalent to 16 - 22% of the total CO2 emissions to the atmosphere from burning fossil fuels that year. According to Phillips et al., 2009, "The exceptional growth in atmospheric CO2 concentrations in 2005, the third greatest in the global record, may have been partially caused by the Amazon drought effects documented here." The Amazon stores CO2 in its soils and biomass equivalent to about fifteen years of human-caused emissions, so a massive die-back of the forest could greatly accelerate global warming. In late 2009, before the 2010 drought, the World Wildlife Federation released a report, Major Tipping Points in the Earth's Climate System and Consequences for the Insurance Sector, which suggested that odds of extreme 2005-like droughts in the Amazon had increased from once every 40 - 100 years, to once every 20 years. The study projected that the extreme droughts would occur once every two years by 2025 - 2050. This year's drought gives me concern that this prediction may be correct. The occurrence of two extreme droughts in the past five years, when no El Niño conditions were present and record warm Atlantic sea surface temperatures occurred, are suggestive of a link between global warming and extreme Amazon drought. If the climate continues to warm as expected, the future health of Earth's greatest rainforest may be greatly threatened, and the Amazon may begin acting to increase the rate of global warming. According to Rosie Fisher, a scientist at the National Center for Atmospheric Research in Boulder, Colorado who specializes in interactions between climate and forests, "I'm genuinely quite alarmed by this. In some ways it kind of reminds me of when they figured out than the Greenland ice sheet was melting much faster than the climate models predicted it would."

Deforestation in Brazilian Amazon falls to lowest rate on record
There is some good news from the Amazon--deforestation rates in the Brazilian Amazon have fallen 14% in the past year, and are at their lowest rate on record, according to mongabay.com, an environmental science and conservation news site that focuses on tropical forests. In 2009, Brazil passed a law committing to a 36 - 39% reduction in emissions of greenhouse gases. Reducing deforestation by 80% by 2020 was the primary method envisioned to achieve the reduction. Brazil is now four years ahead of that schedule, and no longer is the world's biggest deforester--Indonesia now cuts down more acreage of forest each year than Brazil does.

For more information
Nick Sundt at the WWF Climate Blog has a remarkably detailed post on this year's Amazon drought, and Dr. Joe Romm at climateprogress.org has another excellent post.

Phillips, et al., 2009, Drought Sensitivity of the Amazon Rainforest, Science 6 March 2009: Vol. 323 no. 5919 pp. 1344-1347 DOI: 10.1126/science.1164033.

I'll have new post Monday or Tuesday.

Jeff Masters

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446. unf97
Good day WU bloggers!

I hope everyone is doing O.K. A very cold, breezy day in NE FL! The low temp recorded at my home was 27.4 degrees earlier today. Current temp 46.7 degrees at 1:00 p.m.

Expecting lows tonight in the low 20s here at my North Jax location, with possible readings of 18-20 degrees in areas of inland SE GA. Looks like hard freezes up through Thursday morning, then a brief moderation of temperatures ahead of the next arctic front the later part of the week into the weekend with some rain moving in the area Saturday into Sunday. Then, the next blast of arctic air will be moving back in by the start of next week. Model guidance is indicating this next arctic air intrusion next week will be just as cold, if not colder, than this current airmass over the Eastern 2/3 of the CONUS.

An interesting La Nina this year for sure. We are seeing the Omega blocking pattern over Greenland which is for now anchored in place and therefore, at least for most of December, we will see a couple of more of these motherload surges of polar air funneling southbound through the Eastern 2/3 of the CONUS.

Chances are that the shift in the pattern will occur by the start of January 2011 and hopefully we will be seeing milder conditions with maybe slightly warmer than average temps back in Florida and the Deep South, along with continued dry conditions, as we see with typical La Nina seasons in this region.

These arctic intrusions are very unique indeed when they occur in these parts, and it is likely we will see some record minimums to occur this week, and also next week with the next blast of cold air in several areas.
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Quoting Minnemike:
two idiots walk into a blog...
no punchline.

That is a punchline.
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two idiots walk into a blog...
no punchline.
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Quoting PensacolaDoug:
I've been procrastinating on my errands. But I gotta go now, really.

And miss the entertainment?
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I've been procrastinating on my errands. But I gotta go now, really.
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Quoting SQUAWK:
Yup, time to break out the popcorn.

Already done. And since its a little chilly, I have marshmellows, chocolate, and graham crackers ready for my wood-burning fire, to make smores.

YAY for free entertainment!
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Needs a check-up? From the neck up?
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Henny Youngman lives!
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I'd like to help you out. Which way did you come in?
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Quoting HurricaneKatrina:
I went a little overboard there. So called skeptics and brainwashed faux news watchers shouldnt be arrested. The oil and coal execs and their lobbyists should.
I heard you went to have your head examined but the doctors found nothing there.
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Quoting HurricaneKatrina:
An ostrich is very appropriate profile pic. You are just sticking your head in the sand.
I could make a monkey out of you, but why should I take all the credit?
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Quoting PensacolaDoug:
Ostrich's don't actually do that anyway, do they?


From wikipedia "Contrary to popular belief, Ostriches do not bury their heads in sand.[28] This myth likely began with Pliny the Elder (A.D. 23-79), who wrote that Ostriches 'imagine, when they have thrust their head and neck into a bush, that the whole of their body is concealed. Ostriches are known for their denial of obvious truths, however.' "
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Quoting HurricaneKatrina:
Tell that to your grandkids. Im sure they will be delighted to inherit a devastated planet. The Koch funded tea party are a lot more like the nazis. Since when did being a good steward of the earth make anyone a "nazi"?
I don't know what makes you so stupid, but it really works!
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Yup, time to break out the popcorn.
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Quoting HurricaneKatrina:
Dont you have a tea party to attend?
Sit down and give your mind a rest.
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12Z GFS shows the hits keep on coming thru the 22nd of December. Brrr....for the deep south1
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Ostrich's don't actually do that anyway, do they?
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Quoting HurricaneKatrina:
An ostrich is very appropriate profile pic. You are just sticking your head in the sand.

Thank you for noticing.

Notice that my avatar is looking right into the camera, and that he has quite an intellectual and quizzical look as well.

I would much rather my avatar be an 'eyes open' ostrich than that of a hysterical 'we are all going to die' hand wringing Chicken Little.

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Quoting KEEPEROFTHEGATE:
well i see you are a real brain child too bad the best part of you ran down you're daddys leg
Dont you have a tea party to attend?
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Quoting HurricaneKatrina:
We would be off oil and coal if it wasnt for their lobbyists. They are like the tobacco industry. Remember. More doctors smoke camels than any other cigarette.



No we wouldn't. Not even close. And that's a silly analogy.
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Quoting calusakat:


Who let Chicken Little out of the loony cage???

Or was it a carefully planned escape???

Regardless...

Whoever is responsible should get right back here and put him/her back in it.


An ostrich is very appropriate profile pic. You are just sticking your head in the sand.
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Quoting HurricaneKatrina:
December 6 2049.
Hurricane Katy has been upgraded to a category 7 and is headed towards NYC. The Amazon rainforest is burning in continent sized firestorm. MIllions are starving in Africa. The Gulf Stream is shutting down and Europe is plunging into an ice age. The International Criminal Court is prosecuting all lobbyists of the fossil fuel industry. People of the world demand justice as they helplessly watch the climate go into chaos.


Who let Chicken Little out of the loony cage???

Or was it a carefully planned escape???

Regardless...

Whoever is responsible should get right back here and put him/her back in it.


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Quoting PensacolaDoug:



Do you drive a car? Do you walk into a room and turn on a light? A computer? A television set? Do you use any plastics? Medical equipment and medicines? None of that would have been possible w/o the fossil fuel industry. We need to develope other sources I agree, it's easier said than done however. ANd any money thats ever been exchanged between myself and EXXON (or any other oil company for that matter) has flowed to them, not me.
We would be off oil and coal if it wasnt for their lobbyists. They are like the tobacco industry. Remember. More doctors smoke camels than any other cigarette.
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I'm off to run errands... I hope you mind if I drive my vehicle and turn on the heat..It's a little chilly here today.
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http://www.skepticalscience.com/
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Quoting HurricaneKatrina:
I went a little overboard there. So called skeptics and brainwashed faux news watchers shouldnt be arrested. The oil and coal execs and their lobbyists should.



Do you drive a car? Do you walk into a room and turn on a light? A computer? A television set? Do you use any plastics? Medical equipment and medicines? None of that would have been possible w/o the fossil fuel industry. We need to develope other sources I agree, it's easier said than done however. ANd any money thats ever been exchanged between myself and EXXON (or any other oil company for that matter) has flowed to them, not me.
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check weather.gov
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416. eddye
i said frost tonight in weston fl
Member Since: August 12, 2008 Posts: 0 Comments: 1207
Quoting eddye:
jeff 9641 i asked u if there was going 2 be frost and also do u think there will be cold weather when i go 2 orlando december 18
THats a little far out.
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414. eddye
jeff 9641 i asked u if there was going 2 be frost and also do u think there will be cold weather when i go 2 orlando december 18
Member Since: August 12, 2008 Posts: 0 Comments: 1207
Quoting PensacolaDoug:
HurricaneKatrina writes.

Tell that to your grandkids. Im sure they will be delighted to inherit a devastated planet. The Koch funded tea party are a lot more like the nazis. Since when did being a good steward of the earth make anyone a "nazi"?

Wanting to put people in jail because they have doubts about a theory smacks of "thought police". America isn't a police state yet.
I went a little overboard there. So called skeptics and brainwashed faux news watchers shouldnt be arrested. The oil and coal execs and their lobbyists should.
Member Since: Posts: Comments:
HurricaneKatrina writes.

Tell that to your grandkids. Im sure they will be delighted to inherit a devastated planet. The Koch funded tea party are a lot more like the nazis. Since when did being a good steward of the earth make anyone a "nazi"?

Wanting to put people in jail because they have doubts about a theory smacks of "thought police". America isn't a police state yet.
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Quoting Jeff9641:


What a BONEHEAD! You must be related to AL GORE.
calm down hot air inhofe
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Quoting PensacolaDoug:
Re 405

If you're not already, you ought to be writing for Hollywood. That's pretty good!
Lol. I have actually thought about that. :)
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Quoting PensacolaDoug:



That's aload of crap.
You'd a made a good Nazi.
Tell that to your grandkids. Im sure they will be delighted to inherit a devastated planet. The Koch funded tea party are a lot more like the nazis. Since when did being a good steward of the earth make anyone a "nazi"?
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Re 405

If you're not already, you ought to be writing for Hollywood. That's pretty good!
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Quoting IKE:
Heads up for next weekend....6Z GFS @ 174 hours....another plunge of arctic air into the deep south....


The 12Z is similar..Yes, this is a COLD and DRY La Nina..So much for those warmer winter temps..

Levi stated the pattern should change in Late Dec 2010, towards a more "normal La Nina"..We can hope..

Tired of the 29F one morning and 62-75F three days later routine!!!!!
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404. jb410
Quoting Jeff9641:


Morning JB410!


Morning, Jeff!
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Quoting HurricaneKatrina:
Exxon funded contrarians should be sleeping in a jail cell. For ecocide and mass murder.



That's aload of crap.
You'd a made a good Nazi.
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Quoting Dakster:
Hopefully this cold snap will take out the remaining iguanas and non-native snakes infesting south florida...

When it gets cold down here it starts to rain large lizards from the trees.


Iv'e heard of it raining "cats and Dogs" but Lizards and snakes????!!!


Re: 400

That's a little over the top don't ya think?
Might even call it "Fear Mongering". AG would be proud!
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Quoting PensacolaDoug:



In tents if the AGW crowd gets their way!
Exxon funded contrarians should be sleeping in a jail cell. For ecocide and mass murder.
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Quoting PensacolaDoug:



In tents if the AGW crowd gets their way!

...or six feet under if the anti-science crowd gets theirs.

(Personally, a tent sounds better.)
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Hopefully this cold snap will take out the remaining iguanas and non-native snakes infesting south florida...

When it gets cold down here it starts to rain large lizards from the trees.
Member Since: March 10, 2006 Posts: 0 Comments: 10034
Quoting eddye:
where is everybody sleeping



In tents if the AGW crowd gets their way!
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Two feet of snow in Munising, MI and counting due to lake effect snow bands from the WSW earlier last week and now from the NW which started Friday. If the weather was colder the bands wouldn't be as effective. As it is the big lake is warm and able to fire up these bands to the point of a inch an hour in areas.
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396. eddye
where is everybody sleeping
Member Since: August 12, 2008 Posts: 0 Comments: 1207

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.