By the Lawrence Berkeley National Laboratory news service
A blade of grass destined to be converted into biofuel may join energy efficiency and other big-ticket strategies in the effort to reduce atmospheric carbon.
In addition to offsetting fossil-fuel emissions, a potential bioenergy plant such as the grass Miscanthus could also snare carbon from the atmosphere and trap it in the soil for millennia.
Miscanthus, a potential feedstock for biofuel, could pull double duty in the fight against climate change by sequestering carbon in the soil for thousands of years.
Sounds promising. But should scientists genetically engineer bioenergy crops to be better at ridding the atmosphere of the greenhouse gas? And can this strategy take place on the scale needed to mitigate climate change?
These questions are framed in a new analysis by Lawrence Berkeley National Laboratory scientist Christer Jansson and researchers from Oak Ridge National Laboratory. Their research, published in the October issue of Bioscience, explores ways in which bioenergy crops can become a big player in the drive to rein in rising levels of atmospheric carbon dioxide.
The authors hope to get others thinking about engineering plants to not only produce biofuel, but to also sequester carbon.
“We want to encourage discussion and research on this topic,” says Jansson, a senior staff scientist in Berkeley Lab’s Earth Sciences Division and lead author of the analysis. “We need to explore the extent to which plants, and specifically genetically engineered plants, can reduce levels of atmospheric carbon.”
The conversation has already started. Scientific American and other news outlets and blogs have published articles on the team’s analysis since it was published a few weeks ago.
At the heart of the scientists’ analysis is the idea that bioenergy crops can fight climate change in two ways. There’s the obvious way, in which a plant’s cellulosic biomass is converted into a carbon-neutral transportation fuel that displaces fossil fuels. And the not-so obvious way: bioenergy crops also take in atmospheric carbon dioxide during photosynthesis and send a significant amount of the carbon to the soil via roots. Carbon from plant biomass can also be incorporated into soil as a type of charcoal called biochar. Either way, the captured carbon could be out of circulation for millennia.
At stake is the urgent need to make a dent in the nine billion tons of carbon that human activities emit into the atmosphere each year. Natural processes such as plant photosynthesis annually capture about three billion tons of carbon from the atmosphere.
“We could double that in the next several decades,” says Jansson. “By 2050, we could get to five or six gigatons of carbon removed from the atmosphere by plants, and I think a major part of that could come from bioenergy crops like grasses and trees. They could make a big contribution in sequestering carbon, but other strategies will have to be used.” (one gigaton is one billion tons)
Berkeley Lab's Jansson hopes to get scientists thinking about new ways to use bioenergy crops to fight climate change.
As Jansson explains, to increase the capacity for plants to act as carbon sinks, scientists need to continue to develop bioenergy crops that are efficient in harvesting light energy and using the energy to convert carbon dioxide to biomass. Bioenergy crops should also have a high capacity to send the carbon it captures to its roots, where it has the best chance to be stored in soil for thousands of years.
Fortunately, top bionergy crop candidates, such as Miscanthus, are already better-than-average carbon sinks. The large root systems in perennials such as grasses make them better at sequestering carbon in biomass and soil than annual plants.
But can bioenergy crops become even better? Jansson and colleagues outline several possibilities in their analysis. A plant’s canopy can be altered to enhance its efficiency at intercepting sunlight. Another approach accelerates a plant’s photoprotection mechanisms, which would improve its ability to use light. And a plant’s tolerances to various stresses could be improved without compromising yield.
A game-changing success, Jansson explains, could be the design of a bioenergy crop that can withstand drought and which utilizes brine, saline wastewater, or seawater for irrigation to avoid having to tap into freshwater supplies. Jansson suggests that genetic engineering can play a key role in introducing these traits into a plant.
“Bionergy crops are likely to be engineered anyway,” he says. “It makes sense to also consider enhancing their ability to withstand stress and sequester carbon. This analysis will hopefully guide research and prompt people to think in new ways about bioenergy crops.”
Berkeley Lab is a U.S. Department of Energy national laboratory located in Berkeley, California. It conducts unclassified scientific research.
tel jetson wrote: agreed. they start with a solid idea: sequester carbon using plants and use plants for fuel. then they dive headlong into genetic engineering.
I am more afraid of mainstreaming of biofuels than I am of GMO's even and I am rabidly anti GMO. The more land that they use to produce biofuels, the more green house gas emissions there will be...DUH. The mainstream has looked over the true causes of global warming. Hell, I am pro clean fossil fuel use, CO2 is not a f'ing toxin people, it's plant food. Plants can easily absorb 4 times more atmospheric CO2 than is currently in the atmosphere. The problem isn't that we are setting fires (which are smaller and less frequent than they used to be), it's that we are subverting nature and breaking down the diversity and forcefully destroying the landscape. How is the earth supposed to breath if we cut all of it's lungs down and turn them into desert or pollute the oceans so much so they produce c02 instead of oxygen.
We have been making deserts for a really long long time. All of these deserts were once prairie, savanna or forest. All these conditions of lack of plant growth to consume carbon is created all over the place. I think that the soils have just been worn out and it will just take time to heal them. Not only do biofuels create greenhouse gases, but so does their production.
Well managed pasture and forests are the answer as much as I can tell.
Wherever there is a mowed park, that's global warming. Golf courses. Wherever there is pavement, that is global warming. Wherever there are such numerous buildings they outnumber the trees, these are gigantic global warming generators. In some countries people have been painting their roofs white to combat global warming...!
Wherever there is empty unused land, compacted earth, washed away soil, decline in topsoil... this my friends is what global warming truly is.
F biofules, you know why? Because we don't need all this crap. We don't need this computer or a house full of lightbulbs or all these industrial gizmos... If we were smart we would take all the fossil fuels we can access easily without doing much damage and make as many ponds and lakes as we could. Right?
Fossil fuels probably won't destroy the world, but trying to solve the problem of fossil fuels easily could!
when I said "use plants for fuel" I was imagining a cow being powered by grass. I don't think I've got quite the extreme distaste for biofuels that you do, but I certainly don't think they're any great idea.
if it was produced locally in small-ish scale facilities, I wouldn't be surprised if ethanol could make sense as a fuel, particularly if it was made from starchy plants growing in constructed wetlands to treat used water. I agree that we don't need the things that cheap energy makes possible, but that doesn't appear to matter to the folks who have historically waged war on humans and ecologies around the world to get it.
a world with out all this useless crap would be, as far as I'm concerned, better by far. but if I've got to choose between all the useless crap being powered by coal/petroleum/hydro-electric or plant-derived fuel, I would absolutely go for the plant fuel. I wouldn't advocate for vast plantations used only for fuel crops, but I don't believe that's the only way to do it. using multi-purpose plants in the permaculture tradition seems a very viable way to grow starch for fuel.
I agree that there are much more effective ways than changing fuel to deal with CO[sub]2[/sub] and other things that contribute to global warming. but global warming is far from the only reason fossil fuels are nasty.
while humans are responsible for a lot of deserts, they certainly aren't responsible for all of them. irresponsible human activity certainly causes desertification, but so do geological and meteorological processes. the Atacama Desert may not have received any rainfall between 1570 and 1971.
This is why I said Clean fossil fuel use, which doesn't exactly exist I suppose, due to extraction methods, however there is so called clean coal which only emits c02 and all other emissions are cleaned and there isn't much to clean due to the slow burn method they use. There are other examples similar. The point is we could use them sparingly enough I believe that they would not do such drastic harm. The way we are using it, we are actually using fossil fuels to destroy nature, thus no matter what they are destroying the earth.
Good point about CO2 not being a toxin/pollutant, and being plant food.
I had wondered if global warming would extend the growing season in temperate areas allowing deciduous trees to retain their leaves longer and thereby convert more atmospheric CO2? It would be the natural processes balancing out the creation of additional CO2. Maybe global warming is a natural response to man's adding CO2 to the atmosphere and the plant life becomes responsive to this. Just a thought.
Of course, we are wiping out millions of acres of trees, so the balance may not be able to be sustained.