Designer homes made specifically to adapt to the environment and the climate.
Monday, June 24, 2013
Wednesday, June 12, 2013
How Long Until It's Gone?
Estimated decomposition rates of common marine debris items:
Wax Carton 1 monthApple Core 2 months
Cotton Shirt 2-5 months
6-pack Plastic 6 months (if biodegradable)
Plywood 1-3 years
Cigarette Butts 1-5 years
Wool Socks 1-5 years
Plastic Grocery Bag 10-20 years
Foamed Buoy 50 years
Styrofoam Cup 50 years
Tin Can 50 years
Aluminum Can 200 years
6-pack Plastic 400 years
Plastic Bottle 450 years
Disposable Diaper 450 years
Fishing Line 600 years
Glass Bottle Undetermined
Tuesday, March 12, 2013
Ron Finley: A guerilla gardener in South Central LA
Ron Finley plants vegetable gardens in South Central LA -- in abandoned lots, traffic medians, along the curbs. Why? For fun, for defiance, for beauty and to offer some alternative to fast food in a community where "the drive-thrus are killing more people than the drive-bys."
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Aquaponics - 1 MILLION pounds of Food on 3 acres. 10,000 fish 500 yards compost
Growing power seems to have a winning combo going. I underestimated what they are doing. Based on the information in these videos, IF true, then on 3 acres they are producing 1,000,000 pounds of food each year! How are they doing this? Well, based on the information given in the video...
10,000 fish
300-500 yards worm compost
3 acres of land in green houses
Grow all year using heat from compost piles.
Using vertical space
A packed greenhouse produces a crop value of $5 Square Foot! ($200,000/acre).
Now, just to be clear I am not growing power or will allen. Also, a pound of plant or fish product is not the same thing as eatable food unless you process all parts of them for food. i.e. eating the fish bones and using plant stalks in stews. Generally, nations that are well fed throw away most of the plant and eat only the best parts thus lowing the yield of food.
Growing power depends on and runs on the HUGE amounts of compost they make from food waste that is taken from the city. With out this compost there would be no heat for the greenhouses and no fuel for the plants to grow. Its a great thing to divert this from the landfill and provide cheap food for the community.
My personal experience is that growing 7 pounds of food per square foot in a year is not that hard to do especially if you grow year around. You have to select plants that produce a lot of food in a small space which means you may not get a nutritionally complete diet if thats all you grow. Also layering of growth to use all space is important.
I personally use a 12 foot diameter round pond 2.5 feet deep to grow annually 300+ pounds of fish in an aquaponic system and the bulk of my produce is grow using the biointensive method, in the ground, which is watered from the nitrogen rich fish water. My typical yield is between 6 and 9 pounds of food per square foot per year. This does require that I grow over winter which most people do not do. I find that growing in fall and winter months I actually get more production over fall and winter because there are NO bug problems! The crops do mature much slower, but they will mature! Think of it this way, the standard planted row may have 2 or 3 rows of veggies. Bio intensive will plant 12 rows; thats already 4 times the produce. Now add in onions, for example, that grow vertically above sweet potato vines, this increases production a lot. Now add to that 4 harvest per year vs the standard one season growing season. Now you have X4 more productivity. This brings us to X4X4 or 16 times the productivity of the standard growing methods. If you add to that hanging pot or what ever to add more growing space you have again increased productivity again. I personally have not used vertical space in that way. An snap shot of my experience is growing one sweat potato per 1.5' x 1.5' area (2.25 square feet) this one plant produces on average 12 pounds of root per plant and in that space I grow 4 to 6 leeks adding a pond of produce. Now, the vines grow all over the place, and I tie some up, are not confined to that 2.25 square feet of soil space. From each plant you can easily average 3 pounds of eatable leaves as you pick them over the growing season. At this point alone I am averaging 16 pounds of eatable food in 2.25 square feet or 16/2.5=7 pounds of food per square foot. Now that is in ONE GROWING SEASON. As I also grow fava beans, wheat, and fodder greens for two more seasons so my yelid is averaging 8 to 10 pounds in a year. IF I did this on 3 acres of growing space, excluding foot paths and green house walls ect then my production would be 8 pounds per square foot * 43560 feet acre * 3 = 1,045,440 pounds of food. It is possible to get even more by choosing the right crops and getting 4 harvest per year. I have settled on 4000 square feet of growing space per person for providing pretty much all the food a person needs. I suggest anyone starting out begin with a very small garden and do it well. Something like a 5' by 20' growing bed would be the most you would start with.
SUGGESTED READING:
backyardaquaponics [dot] com/forum
Food Now by bountiful gardens
One Mexican Diet by bountiful gardens
Four Season Harvest by Eliot Coleman
Winter Harvest Handbook by Eliot Coleman
Monday, February 6, 2012
Solar Tent for High-tech Campers
Source: design-dautore.com
Futuristic concept tent can harness solar energy to provide electricity to portable gadgets.
Orange, utilizing cutting edge technology in solar harnessing PVs
Specially coated solar threads are woven into conventional fabric and can be folded easily. Because of its light weight it sets you free from carrying conventional heavy solar panels. The three directional glides can be rotated in any direction to follow the sun whole day. Not only this, but it incorporates ‘glo-cation’ technology which helps the festive-goers to track the location using either an SMS message or automatic active RFID technology.
It will make the tent glow in dark so that you can easily recognize your destination. At the heart of the tent lies a central wireless control hub which indicates the amount of energy generated on a flexible touchscreen LCD display screen. Further, the tent includes an internal heating element embedded within the tent’s groundsheet which is controlled by the central hub.
Tuesday, August 9, 2011
Rawesome Shutdown: The War on Food Freedom
Rawesome Shutdown: The War on Food Freedom
by Shiva RoseHuffington Post
8/9/11
"If the people let government decide what foods they eat and what medicines they take, their bodies will soon be in as sorry a state as are the souls of those who live under tyranny." -- Thomas Jefferson.
It always seemed preposterous to me that we have to continuously fight to maintain our reproductive rights, but now the government has decided they are going to determine what we eat, as well. What if I don't want to consume packaged food riddled with antibiotics? What if I don't want to shop at Whole Foods, where they produce the main staples? What if I refuse to shop at Trader Joes where the source of their food is Monsanto based agro business? What if I want to give my children fresh, unpasteurized milk from a grass-fed cow so they have all the incredible enzymes and vitamins that was the way nature intended? The government is now wanting to dictate how and what I feed my family, which seems as undemocratic as telling me I have no right to choose what happens with my reproductive decisions.
This week, Rawesome, a legal food club in Venice, California, was illegally shut down by a Multi-agency armed unit and over thousands of dollars worth of fresh food and produce destroyed. The SWAT style, helmet wearing, gun carrying enforcement agents came rushing in as if they were seizing heroin or dealing with gangsters.
Instead, in their ridiculous theatrical act, they dumped gallons of pure, unpasteurized milk and took possession of organic coconuts. (Really? Coconuts? Can't our tax dollars be spent on attacking real criminals and destroying drugs?) The owner of Rawesome, James Stewart, was then arrested and charged with a bail of $123, 000. Along with Stewart, Sharon Palmer of Healthy Family Farms was also arrested with a ridiculous bail amount. Palmer's farm is a sustainable; pasture-based farming operation where they raise all the animals from birth. They do not feed their animal's corn or soy or dose them with antibiotics. This is the criminal our tax dollars is putting behind bars.
For the last couple of years I have barely walked into a traditional grocery store. Yes, I visit one for some basic goods and household products, but generally I get my food for the week at the Santa Monica Farmer's Market for fresh organic produce, and then at Rawesome for milk, cheese, butter, oils, meats, eggs, snacks, treats, nuts, juices, nut milks, yogurt, kiefer, ghee and so much more. Since I have been feeding my daughters unpasteurized products, we have not caught one cold or flu bug. All the health issues that used to plague me for years have dissipated.
I not only feel better than ever, but I also feel good about knowing where my food comes from, and from supporting a community of farmers that I respect. Now my comforting nourishing routine has been shattered in a violent, illegal way. The question is, why is our government so fearful of these farmers and products? Are the dairy lobbyists behind these violent actions? Is Whole Foods? In the brilliant documentary Farmageddon, Kristin Canty exposes how the government has been targeting small, local, family owned farms instead of focusing on food safety.
These arrests were on charges of criminal conspiracy stemming from illegal sales of unpasteurized goat milk and cheese. The arrests are a result of a year-long sting. While it's legal to manufacture and sell unpasteurized dairy products in California, licenses are required. So in essence the government has spent our dollars to plan an undercover sting action and arrest these folks because they may have sold some cheese to a non-coop member? Why go through all of this trouble unless someone is truly worried and afraid. Perhaps they know that there is a massive, determined, passionate movement afoot that may someday jeopardize the corrupt and insidious agro businesses.
Just this week, Mother Jones published a piece about how a resistant bacteria has infiltrated the meat sources here in the U.S. Also this week there have been deaths in California from salmonella tainted turkey meat. This is all a result of the over-use of antibiotics in the agro farms: "The U.S. meat industry uses 29 million pounds of antibiotics every year." In Europe, this has been banned and in Sweden it has been banned for 20 years, but here we continue to raise our animals with corn, soy and antibiotics. If enough of us get smart and start consuming grass-fed animals, the agro business will lose profits. Is this what is fueling the shut down of family owned natural farms?
I am truly devastated by the Rawesome shut down. It should be my choice how I feed my family, not the government's. I am furious that I will have to purchase pure, nourishing, enzyme rich food on the sly, somehow as if I was buying contraband drugs. I am disgusted that they believe we are "terrorists" for wanting control of our food source. I want my tax dollars to be spent on finding ways to really protect us from mainstream poison found in the meat and dairy. I refuse to give my children the bleached water they like to call milk that is inhumanely dragged out of corn-fed cattle udders. Perhaps I will have to find my own farm and produce my own food source. Perhaps we all need to take control of our health and fight for food freedom.
More from Shiva Rose at thelocalrose.com.
Sunday, February 13, 2011
The Eight Principles of Successful Water Harvesting
1. Begin with long and thoughtful observation.
Use all your senses to see where the water flows and how. What is working, what is not? Build on what works.
2. Start at the top (highpoint) of your watershed and work your way down.
Water travels downhill, so collect water at your high points for more immediate infiltration and easy gravity-fed distribution. Start at the top where there is less volume and velocity of water.
3. Start small and simple.
Work at the human scale so you can build and repair everything. Many small strategies are far more effective than one big one when you are trying to infiltrate water into the soil.
4. Slow, spread, and infiltrate the flow of water.
Rather than having water run erosively off the land’s surface, encourage it to stick around, “walk” around, and infiltrate into the soil. Slow it, spread it, sink it.
5. Always plan an overflow route, and manage that overflow as a resource.
Always have an overflow route for the water in times of extra heavy rains, and where possible, use the overflow as a resource.
6. Maximize living and organic groundcover.
Create a living sponge so the harvested water is used to create more resources, while the soil’s ability to infiltrate and hold water steadily improves.
7. Maximize beneficial relationships and efficiency by “stacking functions.”
Get your water harvesting strategies to do more than hold water. Berms can double as high-and-dry raised paths. Plantings can be placed to cool buildings in summer. Vegetation can be selected to provide food.
8. Continually reassess your system: the “feedback loop.”
Observe how your work affects the site, beginning again with the first principle. Make any needed changes, using the principles to guide you.
Principles 2, 4, 5, and 6 are based on those developed and promoted by PELUM, the Participatory Ecological Land-Use Management association of east and southern Africa. Principles 1, 3, 7, and 8 are based on my own experiences and insights gained from other water harvesters.
These principles are the core of successful water harvesting. They apply equally to the conceptualization, design, and implementation of all water-harvesting landscapes. You must integrate all principles, not just your favorites, to realize a site’s full potential. Used together, these principles greatly enhance success, dramatically reduce mistakes, and enable you to adapt and integrate a range of strategies to meet site needs. While the principles remain constant, the strategies you use to achieve them will vary with each unique site.
For a thorough introductory description of water-harvesting principles and additional ethics see Rainwater Harvesting for Drylands and Beyond, Volume 1 (Rainsource Press, 2006).
Saturday, February 12, 2011
MIT Professor Noam Chomsky on Why America Can't Tackle Climate Change (Video)
by Brian Merchant, Brooklyn, New York
treehugger.com
02.10.11
treehugger.com
02.10.11
Image: cloud2013, Flickr, CC
Noam Chomsky has a big ol' brain, and over the years, he's devoted it to revolutionizing linguistics, pushing the boundaries of analytic philosophy, formulating trenchant political theory, and pissing off establishment figures. Whether or not you agree with his politics, there's no denying that he's a sharp fella. Which is why it's well worth watching his take on why the United States has thus far failed to tackle climate change:
Yes, I know YouTube lists the running time as 20+ minutes, but to get the climate-related part, you only need to listen to the first few. Much of this has been said before -- that vested interests have been successful in confusing the American public by bombarding them with misinformation from various sources, that the media's failure in covering the climate story is twofold, and that the interests that combat climate action have institutional prerogatives to do so -- but Chomsky pulls it together so well, it could serve as a crash course on the roots of climate denial.
There's a bunch of interesting commentary on labor, health care, and the outsourcing of jobs -- even green ones -- that fills the second chapter of the vid, so if you have some time, it's worth a peek as well.
More on America and Climate Change
33 US Generals & Admirals Say " Climate Change is Threatening National Security"
How Climate Change Could Destroy America
Thursday, February 10, 2011
How many trees are needed to make a given amount of paper?
According to the USDA, each year 20,000,000 (million) trees taking up 5,000,000 acres of "natural" forest is cut down to produce 27,000 tons of paper for the publishing industry. Also consider the loss in nature's ability to cleanse the air we breathe as well as its contribution to global climate.
Here are some of the hard facts; some alternative solutions to a thorny problem; and some simple, inexpensive and inspiring ways each of us can help. We’ll start with
THE BAD NEWS
- The most diverse forests in North America, which are in the Southern United States, contain the largest paper producing region in the world.
- 20 million trees, or 5 million acres of natural forest, are cut down to make 27,000 tons of wood pulp used for the production of paper.
- Of the global wood harvest, 42% goes to paper production.
- The global production of pulp, paper and publishing is expected to increase 77% by the year 2020.
- The United States is claimed to have 6 times the per capita consumption of paper over the world average.
- The paper industry is the third highest emitter of industrial greenhouse gases to the air in the world, and the fifth highest emitter of industrial toxic waste to water.
- The planet is exposed to 250,000 metric tons of toxic pollutants from paper manufacturers each year.
ALTERNATIVE SOLUTIONS
1. Tree Farms
- Replacing natural forest with tree farms creates a relatively reliable source of wood pulp, but reduces by 90% the number of species contained in a natural forest.
- The conversion of forests to tree farms leads to a radical loss of freshwater, air quality, soil cohesion and animal, insect, bird and plant species.
- Rural communities in and around these tree farms and their paper mills tend to be degraded economically and socially.
- South American “paper forests,” as they are called, are expected to grow 70% by the year 2012.
2. Recycled Paper
Paul Hawken, co-founder of the Green Press Initiative has said that if all books were printed on recycled paper, the act of publishing and reading would begin to heal our forests and promote sustainable economic activity.
Currently, recycled paper represents less than 8% of the entire printing and writing market, because publishers claim it is not cost effective. However, market pricing analysis shows that switching from virgin fibers to 100% post-consumer recycled paper would equal an increase of about 20 cents per book. Many readers polled claimed a willingness to spend an extra dollar for books printed on recycled paper.- It takes an estimated one ton of recycled stock to make one ton of paper, while it takes an estimated two to three and half tons of virgin trees to make that same ton of paper.
- One ton of recycled paper can save the equivalent of 24 trees of 40 foot height, 6 to 8 inch diameter.
- One ton of recycled paper can save the equivalent of 7000 gallons of water; 60 pounds of air pollution; and 4100 killowatt hours of electricity.
3. Alternative, annual crops used for papermaking
Kenaf, which grows well in the Southeastern US, has a 3 to 5 times greater yield than the Southern pines which grow in the same region. Related to the hibiscus, it is originally an African plant which can grow up to 14 feet tall in under five months.
- Industrial hemp, related to, but not the same plant as, marijuana grows up to 16 feet tall in 4 months, producing an estimated 10 tons an acre. It is not (yet) legal in the US.
- Straw, the agricultural residue of a multitude of plants, goes underutilized every year in the US by an estimated 150 tons.
- Visit http://www.lucidskies.com/paper.html for more information.
How Can I Help?
SIMPLE WAYS TO MAKE A DIFFERENCE
First of all, live your life as if everything was interconnected, everything was alive and everything was a miracle.
- Spend time in the woods.
- Support tree planting groups, like TreePeople; Trees for the Future; and American Forests
- Support paper recycling efforts: Green Press Initiative; Environmental Paper Network (a consortium of environmental groups)
- Learn about alternative fibers
- Make conscious lifestyle changes
- Plant a tree, either by donating to one of the tree-planting organizations, or in your own town.
About Carolyn North
 |
| Photo by Susan Wilson |
Carolyn North is a writer, healer and social activist whose latest book, ECSTATIC RELATIONS, A Memoir of Love has prompted this action to collaborate with TreePeople to protect the forests that are sacrificed daily for the printing of her books, and all the books we all read.
Long an advocate of healthy forests, she has worked at the Manitou Forest Sanctuary in southern Vermont, and also built the first permitted load-bearing, rice strawbale house in this country, in Northern California.
To learn more about her work – including her 8 published books – visit her website at: http://www.healingimprovisations.net
About Tree People
TreePeople has planted over 2 million trees in the Los Angeles area since 1973 in its work to help nature heal our cities. Having one of the nation's largest environmental education programs, TreePeople offers sustainable solutions to urban ecosytem problems including water, air quality, energy conservation and flood prevention. Originally started by teenagers, it is one of the most innovative, comprehensive and people-friendly environmental groups in the United States.
Publishers, authors and readers are invited to join Carolyn North and TreePeople to mitigate the impact on the environment in the following ways:
A donation of $25 will plant a tree and provide a 1-year membership to TreePeople. $100 will plant a grove of 5 trees
DONATE ONLINE at http://treepeople.org/
Source: http://www.ecstaticrelations.com/booksintotrees/------------------------------------------------------------------------------------------------------
There is no simple answer to these questions, and all calculations can be no better than "ballpark estimates."
Many people have heard the statistic that "a ton of recycled paper saves 17 trees." The "17 trees" number was popularized by Conservatree when it was a paper distributor, based on a report to Congress in the 1970s. It was calculated for newsprint, which is made in a totally different papermaking process from office and printing papers. But it was the best number anyone had, so it became the number everyone used to calculate number of trees saved by recycled paper, or number of trees cut to make virgin paper, no matter what type of paper they were talking about.
Paper is made from a mix of types of trees. Some are hardwood, some are softwood. In addition, some are tall, some old, some wide, some young, some thin. Many of the "trees" used to make paper are just chips and sawdust.
So how can one talk about a "typical tree"? And do numbers calculated 30 years ago still apply to today's much more efficient paper industry?
We decided it was time to update these numbers, so Conservatree has tracked down some ways to make ballpark estimates more reliable than in the past.
CONSIDERATIONS IN CALCULATING TREES TO PAPER
What kind of paper are you talking about?
Paper made in a "mechanical" or "groundwood" process (e.g. newsprint, telephone directories, base sheet for low-cost coated magazine and catalog papers)
uses trees about twice as efficiently as
paper made in the "kraft" or "freesheet" process (e.g. office and printing papers, letterhead, business cards, copy paper, base sheet for higher-quality coated magazine and catalog papers, advertising papers, offset papers).
Is the paper "coated" or "uncoated"?
The fiber in a coated paper (most often used for magazines and catalogs, with a clay coating that may be glossy or matte, or other finishes) may be only a little more than 50% of the entire sheet, because the clay coating makes up so much of the weight of the paper.
As a ballpark estimate, you can use .64 as the fiber estimate for coated papers compared to the entire weight of the sheet. (Fiber estimate calculation by Alliance for Environmental Innovation)
So how many trees would make a ton of paper?
Claudia Thompson, in her book Recycled Papers: The Essential Guide (Cambridge, MA: MIT Press, 1992), reports on an estimate calculated by Tom Soder, then a graduate student in the Pulp and Paper Technology Program at the University of Maine. He calculated that, based on a mixture of softwoods and hardwoods 40 feet tall and 6-8 inches in diameter, it would take a rough average of 24 trees to produce a ton of printing and writing paper, using the kraft chemical (freesheet) pulping process.
If we assume that the groundwood process is about twice as efficient in using trees, then we can estimate that it takes about 12 trees to make a ton of groundwood and newsprint. (The number will vary somewhat because there often is more fiber in newsprint than in office paper, and there are several different ways of making this type of paper.)
SOME TYPICAL CALCULATIONS
1 ton of uncoated virgin (non-recycled) printing and office paper uses 24 trees
1 ton of 100% virgin (non-recycled) newsprint uses 12 trees
A "pallet" of copier paper (20-lb. sheet weight, or 20#) contains 40 cartons and weighs 1 ton. Therefore,
1 carton (10 reams) of 100% virgin copier paper uses .6 trees
1 tree makes 16.67 reams of copy paper or 8,333.3 sheets
1 ream (500 sheets) uses 6% of a tree (and those add up quickly!)
1 ton of coated, higher-end virgin magazine paper (used for magazines like National Geographic and many others) uses a little more than 15 trees (15.36)
1 ton of coated, lower-end virgin magazine paper (used for newsmagazines and most catalogs) uses nearly 8 trees (7.68)
How do you calculate how many trees are saved by using recycled paper?
(1) Multiply the number of trees needed to make a ton of the kind of paper you're talking about (groundwood or freesheet), then
(2) multiply by the percent recycled content in the paper.
For example,
1 ton (40 cartons) of 30% postconsumer content copier paper saves 7.2 trees
1 ton of 50% postconsumer content copier paper saves 12 trees.
Source: http://www.conservatree.org/learn/EnviroIssues/TreeStats.shtml
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Number of trees for BOOKS:
U.S.: 30 million per year
Number of tress for NEWSPAPERS (and magazines):
U.S.: 90 million per year
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Number of trees per magazine:
"A standard sized tree, if there is such a thing (10-15m tall, 1-1.5 m circumference) can make enough pulp for 8000-13000 sheets of paper.
If your magazine has say, 100 sheets, that's 80-130 magazines per tree. Your magazine might take .0075-.0125 trees."
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Number of trees to produce PHONEBOOKS:
Did you know that up to 5 million trees are cut down each year to create the white pages phone book and that only 22% of recipients recycle when disposing of them which equates to 165,000 tons of waste in landfills? In addition, almost 75% of consumers are completely unaware of the environmental and financial impact in printing, delivering and recycling these books. Given that you likely use online directories, social networks and mobile phone applications to find the contact information you need, it simply does not make sense to have the white pages phone books forcefully delivered to us every year.
Source: http://www.banthephonebook.org/
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 | ||||||
| What is Green Press Initiative? When was GPI founded? What are the impacts of the paper industry and books/newspapers? Impacts on Endangered Forests: Impacts on Climate Change GPI worked to complete the first ever Environmental Trends and Climate Impacts report for the U.S. book industry. It was the first comprehensive carbon footprint analysis of a publishing sector and is being used as a model in other paper sectors. This assessment found that the entire book industry, through all steps of production, retail, and publishing activities, emits a net 8.85 pounds per book. Impacts on Communities What is the Book Industry Treatise on Environmentally Responsible Publishing? What are the benefits of recycled paper? What are the benefits of Forest Stewardship Council (FSC) certified papers? What progress has been achieved in recent years? | ||||||
Tuesday, February 8, 2011
Mass tree deaths prompt fears of Amazon 'climate tipping point'
Scientists fear billions of tree deaths caused by 2010 drought could see vast forest turn from carbon sink to carbon source
Aerial view of a drought-affected area within the Amazon basin in Manaus, Brazil. Photograph: Rodrigo Baleia/LatinContent/Getty Images
Billions of trees died in the record drought that struck the Amazon in 2010, raising fears that the vast forest is on the verge of a tipping point, where it will stop absorbing greenhouse gas emissions and instead increase them.
The dense forests of the Amazon soak up more than one-quarter of the world's atmospheric carbon, making it a critically important buffer against global warming. But if the Amazon switches from a carbon sink to a carbon source that prompts further droughts and mass tree deaths, such a feedback loop could cause runaway climate change, with disastrous consequences.
"Put starkly, current emissions pathways risk playing Russian roulette with the world's largest forest," said tropical forest expert Simon Lewis, at the University of Leeds, and who led the research published today in the journal Science. Lewis was careful to note that significant scientific uncertainties remain and that the 2010 and 2005 drought – thought then to be of once-a-century severity – might yet be explained by natural climate variation.
"We can't just wait and see because there is no going back," he said. "We won't know we have passed the point where the Amazon turns from a sink to a source until afterwards, when it will be too late."
Alex Bowen, from the London School of Economics and Political Science's Grantham research institute on climate change, said huge emissions of carbon from the Amazon would make it even harder to keep global greenhouse gases at a low enough level to avoid dangerous climate change. "It therefore makes it even more important for there to be strong and urgent reductions in man-made emissions."
The revelation of mass tree deaths in the Amazon is a major blow to efforts to reduce the destruction of the world's forests by loggers, one of the biggest sources of global carbon emissions. The use of satellite imagery by Brazilian law enforcement teams has drastically cut deforestation rates and replanting in Asia had slowed the net loss. Financial deals to protect forests were one of the few areas on which some progress was made at the 2010 UN climate talks in Cancún.
The 2010 Amazonian drought led to the declaration of states-of-emergencies and the lowest ever level of the major tributary, the Rio Negro. Lewis, with colleagues in Brazil, examined satellite-derived rainfall measurements and found that the 2010 drought was even worse than the very severe 2005 drought, affecting a 60% wider area and with an even harsher dry season.
On the ground, the researchers have 126 one-hectare plots spread across the Amazon, in which every single tree is tagged and monitored. After 2005, they counted how many trees had died and worked out how much carbon would be pumped into the atmosphere as the wood rotted. In addition, the reduced growth of the water-stressed trees means the forest failed to absorb the 1.5bn tonnes of carbon that it would in a normal year.
Applying the same principles to the 2010 drought, they estimated that 8 billion tonnes of CO2 will be released - more than the entire 7.7bn tonnes emitted in 2009 by China, the biggest polluting nation in the world. This estimate does not include forest fires, which release carbon and increase in dry years.
"The Amazon is such a big area that even a small shift [in conditions] there can have a global impact," said Lewis.
Lewis said that two such severe droughts in the Amazon within five years was highly unusual, but that a natural variation in climate over decade-long periods cannot yet be ruled out. The driving factor of the annual weather patterns is the warmth of the sea in the Atlantic. He said increasing droughts in the Amazon are found in some climate models, including the sophisticated model used by the Hadley centre. This means the 2005 and 2010 droughts are consistent with the idea that global warming will cause more droughts in future, emit more carbon, and potentially lead to runaway climate change. "The greenhouse gases we have already emitted may mean there are several more droughts in the pipeline," he said.
Lewis said that the 2010 drought killed "in the low billions of trees", in addition to the roughly 4 billion trees that die on average in a normal year across the Amazon. The researchers are now trying to raise £500,000 in emergency funding to revisit the plots in the Amazon and gather further data.
Brazilian scientist Paulo Brando, from the Instituto de Pesquisa Ambiental da Amazônia (Amazon Environmental Research Institute), and co-leader of the research said: "We will not know exactly how many trees were killed until we can complete forest measurements on the ground. It could be that many of the drought-susceptible trees were killed off in 2005. Or the first drought may have weakened a large number of trees so increasing the number dying in 2010."
Brando added: "Our results should be seen as an initial estimate. The emissions estimates do not include those from forest fires, which spread over extensive areas of the Amazon during hot and dry years and release large amounts of carbon."
Note: The original version of this article incorrectly reported the amount of carbon Lewis's team estimated would be released in 2010 as 8.5 billion tonnes of CO2: the actual figure is 8bn.
Climate tipping points
Scientists know from the geological record that the Earth's climate can change rapidly. They have identified a number of potential tipping points where relatively small amounts of global warming caused by human activities could cause large changes in climate. Some tipping points, like the losses to the Amazon forests, involve positive feedback loops and could lead to runaway climate change.
Arctic ice cap: The white ice cap is good at reflecting the Sun's warming light back into space. But when it melts, the dark ocean uncovered absorbs this heat. This leads to more melting, and so on.
Tundra: The high north is warming particularly fast, melting the permafrost that has locked up vast amounts of carbon in soils for thousands of years. Bacteria digesting the unfrozen soils generate methane, a potent greenhouse gas, leading to more warming.
Gas hydrates: Also involving methane, this tipping point involves huge reservoirs of methane frozen on or just below the ocean floor. The methane-water crystals are close to their melting point and highly unstable. A huge release could be triggered by a little warming.
West Antarctic ice sheet: Some scientists think this enormous ice sheet, much of which is below sea level, is vulnerable to small amounts of warming. If it all eventually melted, sea level would rise by six metres.
• Rate of tree deaths in western US 'rising due to climate change'
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