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Scientists Say Nature ‘Is Better at Carbon Farming’

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By Paul Brown, Climate News Network

LONDON – Large forests planted with a single species of tough small trees could capture enough carbon from the atmosphere to slow climate change and green the world’s deserts at the same time, researchers say.

A group of German scientists says the tree Jatropha curcas is resistant to arid conditions and can thrive where food crops would not survive.

Jatropha curcas could be the way to remove atmospheric carbon, the researchers say.
Credit: Immersia via Wikimedia Commons

Unlike other geo-engineering schemes, which are expensive and rely on humans interfering with nature, this project merely encourages natural tree growth.

Under the slogan “Nature Does it Better,” the scientists say the costs are comparable with the estimated cost of developing carbon capture and storage (CCS) technology at power stations. With only a small proportion of the world’s deserts, they say, these trees could take out most of the additional carbon dioxide emitted by humans since the beginning of the industrial revolution.

The study, published in Earth System Dynamics, a journal of the European Geosciences Union, says “carbon farming” addresses the root source of climate change by taking carbon out of the atmosphere as fast as we put it in.

One hectare (.0039 square miles) of Jatropha trees can take 25 tons of carbon dioxide out of the air annually over 20 years. As it grew, a plantation occupying just 3 percent of the Arabian Desert would remove from the atmosphere the same amount of CO2 as all the motor vehicles in Germany produced over the same period.

The German scientists say all they are doing is working with nature. The trees would need a little help, however, in the form of water. The team therefore proposes starting the plantations near the coast where desalination plants would provide enough water to get the saplings established.

“To our knowledge, this is the first time experts in irrigation, desalination, carbon sequestration, economics and atmospheric sciences have come together to analyze the feasibility of a large-scale plantation to capture carbon dioxide in a comprehensive manner.

Next stop: field trials

“We did this by applying a series of computer models and using data from Jatropha curcas plantations in Egypt, India and Madagascar,” says Volker Wulfmeyer of the University of Hohenheim in Stuttgart.

A graphic demonstrating how the Jatopha curcas project work. (click to enlarge)
Credit: Becker

The idea has a price tag of 42 to 63 euros per ton of carbon removed from the atmosphere, roughly the same cost as CCS, which is much favored by the UK and other governments as one of the “solutions” to mitigate climate change.

But there are more advantages. After a few years, the trees would produce bio-energy (in the form of tree trimmings) to support the power production required for the desalination and irrigation systems.

“From our point of view, afforestation as a geo-engineering option for carbon sequestration is the most efficient and environmentally safe approach for climate change mitigation.

“Vegetation has played a key role in the global carbon cycle for millions of years, in contrast to many technical and very expensive geo-engineering techniques,” said lead author Klaus Becker, also from the University of Hohenheim.

A known advantage of planting trees in arid regions is that they increase cloud cover and rainfall, a further greening of the desert. On the minus side, irrigation can lead to a build-up of salt in the soil, damaging the plantation.

Although the researchers have done computer simulations of the effects of these plantations on deserts, there is no substitute for a pilot project. They are hoping their paper will stimulate enough interest and money to begin field trials of the idea.

Paul Brown is a joint editor for Climate News Network. Climate News Network is a news service led by four veteran British environmental reporters and broadcasters. It delivers news and commentary about climate change for free to media outlets worldwide.

Comments

By Stewart Hardison (Bainbridge, NY 13733)
on August 11th, 2013

This is a tremendously exciting concept.  One can only hope that it scales to level envisioned.  Of course, this species of tree should be (at least I hope) adaptable to semi-arid regions as well, such as the scrub deserts of the Americas.  In these vast regions, irrigation may not be required for this species of tree to flourish.  Only field trials will tell.

Lester Brown, Director of The Earth Policy Institute, has proposed the planting of billions of trees world wide as part of his Plan B initiative to restore the earth’s ecosystems, reduce CO2 emissions and mitigate global warming.  This concept seems like a great fit for Plan B. 

Thanks for bringing this news to the public.

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By Dave (Basking Ridge, NJ 07920)
on August 11th, 2013

“One hectare (.0039 square miles) of Jatropha trees can take 25 tons of carbon dioxide out of the air annually over 20 years.”

“With only a small proportion of the world’s deserts, they say, these trees could take out most of the additional carbon dioxide emitted by humans since the beginning of the industrial revolution. “

The Jatropha tree plantation concept has a reported potential benefit regarding carbon sequestration at the local level. But unfortunately, and as far as I can see, the numbers do not add up to support the much more grandiose geo-engineering claim reported here and as specifically quoted above.

The Max Planck Society reported that global CO2 emissions amounted to 35.6 billion tons (Gt) in 2012…which is just one of the couple of hundred or so years since the beginning of the industrial revolution. Let’s consider what it would take to remove just that one year’s worth of global CO2 emissions and forget for now the other few hundred Gt of excess CO2 in the atmosphere which have accumulated over the past 200 years or so.

Assuming a removal rate of 25 tons per year per hectare then to remove 2012’s emissions and then keep up with global emissions at the 2012 rate you would need to first quickly plant a 5.5 million square mile mega forest of trillions of these trees, which is an area equal to about that of the Sahara, Arabian, Gobi and Kalahari deserts combined. For comparison, the area of the Amazon rainforest is given as 2.1 million square miles. Then just to keep up with increases in energy related CO2 emissions more trees would have to be planted each year in major new forests or green extensions elsewhere on the planet equal to roughly half or more of the land area of Germany – and that’s every year.

Ignoring the claim here of being able to remove hundreds of years worth of excess CO2 from the atmosphere, this scheme is clearly not realistic if it is intended for and ‘sold as’ a significant global climate change mitigation option in the face of business-as-usual global CO2 emission rates. But of course, beyond that, if we could somehow turn the Arabian Peninsula and other nearby arid regions into vast green forests people in the Middle East would be overjoyed and mid East geopolitics would no doubt improve overnight. I am all for that.

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By Nick
on August 12th, 2013

This is nonsense. The main reason CCS isn’t working at scale is because its unfeasably expensive, so any alternative that’s just as costly is a non-starter. Give me 50 Euros a tonne and I’ll show you mixed native species woodland creation going on right here in the UK, but it’s not the answer to global warming.

As someone once said, you can’t offset the lithosphere with the biosphere. Until global carbon emissions start coming down, we’re in the doo-doo.

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By Lewis Cleverdon
on August 12th, 2013

While the principle of Carbon Recovery via afforestation is eminently sound in principle, this reports fails to address the option objectively, and makes untenable assumptions.

First, the costs of Jatropha monoculture established by desalination plants mean that it is simply a non-starter on any relevant scale. See CCS development over 20 yrs (near zero) for the viability of that level of $ /T CO2.

Second, 25Ts carbon intake per hectare per year equates to over 50Ts dry wood growth /Ha /yr, which is over three times what the most productive natural conditions produce, and it is proposed as the output on desert sands.

As a profit stream for carbon offsets it may seem appealing, but that of course is subject to exposure to lightning and destructive pests, and would thus carry some rather severe insurance costs. It also faces furious opposition from those who view any Geo-E project as undermining the effort for emissions control.

Recovering our carbon from the atmosphere is a critically important objective, but this is very obviously not the way to go about it. It fails on financial, social, silvicultural, procedural, ecological, and diplomatic grounds.

Regards,

Lewis

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By Miner49er (Glenview IL 60025)
on August 12th, 2013

This kind of research is just busy-work for “scientists” that don’t have enough to do. The real carbon farming that occurs continuously is the recycling of free CO2 into carbonate rocks by natural processes.

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By Lynn (Edinburg, Texas 78539)
on August 13th, 2013

I’m wondering if they are also experimenting with the MORINGA TREE, which grows over 30 feet tall in a few years in poor soil and arid conditions, taking up very little space, and is not only good for biofuel, but also nutritious food—the fruit (called “drumsticks”), leaves and flowers, which have high iron and calcium content, and tremendously improves milk production in cattle and lactating mothers, etc.  See http://www.treesforlife.org/our-work/our-initiatives/moringa & PowerPoint in lower left column.

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By Charles (Pasadena, Ca)
on August 13th, 2013

Nick your comment makes a lot less sense than carbon capture in the equatorial deserts. Why? Because deserts there have no change in seasons while the UK has a defined growing season that is much, much shorter. Plus these deserts could make a very large change in weather patterns while the UK cannot influence the weather to any extent. The Gulf Stream has more influence on the UK’s weather and it in turn is influenced by the Africa’s deserts.

Equatorial deserts have year-round growing seasons. The UK does not, neither do the taiga forests which are now taking up more carbon than people thought.

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