A new review sums up options for increasing global carbon-sequestration by flora and speculates that genetically engineering crops and trees could enhance the process, trapping gigatons of the greenhouse gas as well as increasing bioenergy production
By Mike Orcutt |October 18, 2010 |
The International Energy Agency predicts that fossil fuels will continue to meet the bulk of rising energy demand for decades to come, but they are currently responsible for 60% of the world's total greenhouse gas emissions. So, managing CO2 emissions from coal, oil and natural gas is crucial in tackling climate change.
Which steps do you think should be prioritized when reducing emissions from fossil fuels?
Human activities currently add about nine gigatons of carbon to the atmosphere yearly. Photosynthetic organisms on land and in the ocean absorb about five of those gigatons through the natural uptake of CO2, leaving to humans the task of dealing with the rest. But no matter how much carbon there is, capturing it and preventing it from reentering the atmosphere is an immense engineering challenge; even today's best technology is orders of magnitude less effective than photosynthesis at trapping atmospheric carbon.
A new analysis published in the October issue of Bioscience suggests that by 2050 humans could offset between five and eight gigatons of the carbon emitted annually by growing plants and trees optimized via genetic engineering both for fuel production and carbon sequestration.
Bioenergy crops represent an opportunity to mitigate atmospheric carbon dioxide in two separate ways, says lead author Christer Jansson, a senior staff scientist at Lawrence Berkeley National Laboratory's Earth Sciences Division. First, they are a carbon-neutral energy source that could offset the burning of fossil fuels. Second, "if they are the right kind of plants, they have a chance to transfer a lot of carbon underground for long-term sequestration," he says.
Plants take up CO2 and store carbon in their biomasses. Carbon can stay for decades or centuries in leaves, stems, branches, seeds and flowers aboveground, whereas carbon allocated to underground root systems is more apt to be transferred into the soil, where it can stay sequestered for millennia. Therefore, an ideal bioenergy plant would produce lots of aboveground biomass for fuel as well as have an extensive root system. Preliminary research indicates that genetic engineering approaches could be employed to enhance both these traits.
Using genetic modification to enhance photosynthesis and thus biomass yield is a realistic approach, says Stephen P. Long, a professor of crop sciences at the University of Illinois at Urbana–Champaign who was not part of the study. Long notes that transgenic tobacco plants, with simple modifications applicable to other plants as well, have already been shown to be more productive. "We are in a position now where we certainly know enough to where we could engineer quite a few of these changes," he says.
Meanwhile, regarding the problem of coaxing plants to allocate more carbon to their root systems, Jansson says an important difference between perennial and annual plants is a good place to start. "Perennials are more efficient than annuals at hiding carbon underground," he says. That's because annuals, which make up most of the world's food crops, spend much more energy producing seeds, stems and leaves than for building their root systems. On the other hand, perennials like switchgrass and Miscanthus have more extensive root systems—necessary because they remain dormant for part of the year and then must grow up again from their roots.
Whereas it may be exciting to imagine a bioenergy or food crop that produces lots of aboveground biomass and has large, carbon-sequestering root systems, research into whether this goal is realistic is still in its early stages. "Perenniality is a complex trait," Jansson says. He suggests it may end up being easier to modify perennials so they possess desirable annual-like features, as opposed to the other way around—but it's too early to tell.
For the short term Jansson is confident that science can modify plants so they are more drought resistant and salt tolerant. Crops that could be maintained with brine or brackish water, such as industrial wastewater or seawater, would help preserve freshwater supplies. "These are important traits that need to be introduced into food and bioenergy crops," Jansson says, adding that "we will see this sooner" than enhanced photosynthesis or perennials with annual traits and/or vice versa.
The authors stress that genetic engineering should not be viewed as a cure-all, but rather part of a larger breeding effort. Further, Jansson says, "One problem is that the different aspects we mention—increasing photosynthesis, improving bioenergy crop yield, and putting more carbon into the root systems—are highly interlinked, and thus not necessarily additive." It could be, for example, that a modifying a plant to grow more roots takes away aboveground biomass production. Again, research in this area is too preliminary to tell.
Allison Thomson, who studies climate change and land use at the Joint Global Change Research Institute in College Park, Md., also expressed the need for caution when interpreting the study's projections. They are valuable in principle, she says, but also based on many assumptions regarding future economic conditions, land availability, and the size of bioenergy's role in a larger future energy strategy. For example, she says, "you can't really say how much bioenergy we are going use if you're not also considering other available energy sources and how much they emit." Furthermore, she points out, whether or not there is a price for carbon, which is hard to account for at this point, will figure heavily into future energy scenarios.
Also important to consider are potential land-use issues related to increasing demand for food. "When we do modeling, that's the one demand you can't ignore," Thomson says. "People want to eat before they want bioenergy."
Besides all the unknowns, there is also existing regulatory policy regarding genetically modified organisms, which imposes high costs of compliance, thereby making it difficult to assess whether the ideas discussed in the paper are all doable, Long says: "The bottleneck and damper on all this is really, 'How do you get transgenics out there, and meet all the regulatory requirements and costs?'"
Tuesday, 19 October 2010
Severn barrage ditched as new nuclear plants get green light
Staff and agencies
guardian.co.uk, Monday 18 October 2010 12.11 BST
The UK government today dropped plans to build a 10-mile barrage across the Severn estuary to generate "green" electricity from tides, as revealed by the Guardian yesterday.
An official study said there was no "strategic case" for investing public money in such a scheme, which could cost more than £30bn, although it said it could be reconsidered as a long-term option.
The Department of Energy and Climate Change paved the way for new nuclear power plants at eight sites: Bradwell, Essex; Hartlepool; Heysham, Lancashire; Hinkley Point, Somerset; Oldbury, South Gloucestershire; Sellafield, Cumbria; Sizewell, Suffolk and Wylfa, Anglesey.
The coalition government has already said it will give the go-ahead to companies who want to build new nuclear plants, provided there is no public subsidy involved, despite the Lib Dems' opposition to new nuclear power stations.
All the potential new sites are in the vicinity of existing nuclear power plants.
Three other proposed sites – at Dungeness in Kent, and Braystones and Kirksanton in Cumbria – were ruled out.
The sites were announced as part of a package aimed at providing certainty for the industry, including more detail on what would be required in terms of clean-up and the government's policy of no subsidies.
The energy secretary, Chris Huhne, said: "I'm fed up with the stand-off between advocates of renewables and of nuclear which means we have neither.
"We urgently need investment in new and diverse energy sources to power the UK.
"We'll need renewables, new nuclear, fossil fuels with carbon capture and storage, and the cables to hook them all up to the grid as a large slice of our current generating capacity shuts down."
The coalition's revised draft national policy statements on energy show that half the new energy capacity built in the UK by 2025 was expected to come from renewables – the majority of which is likely to be wind energy.
But the government dropped plans for large-scale tidal schemes in the Severn estuary, after considering five proposals for three barrages and two "innovative" lagoon-type energy projects to harness the power of the tides.
The most high-profile of the proposed schemes was the 10-mile wide Cardiff-Weston barrage, the costs of which were originally estimated at £15bn but which have now spiralled to more than £30bn, according to the feasibility study published today.
The barrage, which would have harnessed the massive tidal range of the estuary to produce green power, could have met 5% of the UK's electricity needs, but was controversial with some environmentalists because it could destroy thousands of hectares of habitat.
Conservation groups have been fighting the proposals which they believe could destroy the winter feeding grounds of 65,000 birds.
The barrage could also have economic impacts on the area, both positive in creating jobs for the area, and negative in damaging access to the Severn's ports and disrupting recreation such as angling.
The report published today found that the costs of a tidal power scheme would be "excessive" in comparison to other forms of low-carbon electricity generation.
It said a large-scale energy project in the Severn estuary would be costly to deliver and very difficult to finance from the private sector alone, although it did say it should not be ruled out in the longer term as a future option if market conditions changed.
The government said it believed other options, including wind energy and nuclear power, represented a better deal for taxpayers and energy consumers.
And while it acknowledged the feasibility of a Severn barrage could change over time, and there was potential for a future review of the situation, there were no plans to do so before 2015.
Huhne said: "The study clearly shows that there is no strategic case at this time for public funding of a scheme to generate energy in the Severn estuary. Other low-carbon options represent a better deal for taxpayers and consumers.
"However, with a rich natural marine energy resource, world-leading tidal energy companies and universities, and the creation of the innovative Wave Hub facility, the area can play a key role in supporting the UK's renewable energy future."
guardian.co.uk, Monday 18 October 2010 12.11 BST
The UK government today dropped plans to build a 10-mile barrage across the Severn estuary to generate "green" electricity from tides, as revealed by the Guardian yesterday.
An official study said there was no "strategic case" for investing public money in such a scheme, which could cost more than £30bn, although it said it could be reconsidered as a long-term option.
The Department of Energy and Climate Change paved the way for new nuclear power plants at eight sites: Bradwell, Essex; Hartlepool; Heysham, Lancashire; Hinkley Point, Somerset; Oldbury, South Gloucestershire; Sellafield, Cumbria; Sizewell, Suffolk and Wylfa, Anglesey.
The coalition government has already said it will give the go-ahead to companies who want to build new nuclear plants, provided there is no public subsidy involved, despite the Lib Dems' opposition to new nuclear power stations.
All the potential new sites are in the vicinity of existing nuclear power plants.
Three other proposed sites – at Dungeness in Kent, and Braystones and Kirksanton in Cumbria – were ruled out.
The sites were announced as part of a package aimed at providing certainty for the industry, including more detail on what would be required in terms of clean-up and the government's policy of no subsidies.
The energy secretary, Chris Huhne, said: "I'm fed up with the stand-off between advocates of renewables and of nuclear which means we have neither.
"We urgently need investment in new and diverse energy sources to power the UK.
"We'll need renewables, new nuclear, fossil fuels with carbon capture and storage, and the cables to hook them all up to the grid as a large slice of our current generating capacity shuts down."
The coalition's revised draft national policy statements on energy show that half the new energy capacity built in the UK by 2025 was expected to come from renewables – the majority of which is likely to be wind energy.
But the government dropped plans for large-scale tidal schemes in the Severn estuary, after considering five proposals for three barrages and two "innovative" lagoon-type energy projects to harness the power of the tides.
The most high-profile of the proposed schemes was the 10-mile wide Cardiff-Weston barrage, the costs of which were originally estimated at £15bn but which have now spiralled to more than £30bn, according to the feasibility study published today.
The barrage, which would have harnessed the massive tidal range of the estuary to produce green power, could have met 5% of the UK's electricity needs, but was controversial with some environmentalists because it could destroy thousands of hectares of habitat.
Conservation groups have been fighting the proposals which they believe could destroy the winter feeding grounds of 65,000 birds.
The barrage could also have economic impacts on the area, both positive in creating jobs for the area, and negative in damaging access to the Severn's ports and disrupting recreation such as angling.
The report published today found that the costs of a tidal power scheme would be "excessive" in comparison to other forms of low-carbon electricity generation.
It said a large-scale energy project in the Severn estuary would be costly to deliver and very difficult to finance from the private sector alone, although it did say it should not be ruled out in the longer term as a future option if market conditions changed.
The government said it believed other options, including wind energy and nuclear power, represented a better deal for taxpayers and energy consumers.
And while it acknowledged the feasibility of a Severn barrage could change over time, and there was potential for a future review of the situation, there were no plans to do so before 2015.
Huhne said: "The study clearly shows that there is no strategic case at this time for public funding of a scheme to generate energy in the Severn estuary. Other low-carbon options represent a better deal for taxpayers and consumers.
"However, with a rich natural marine energy resource, world-leading tidal energy companies and universities, and the creation of the innovative Wave Hub facility, the area can play a key role in supporting the UK's renewable energy future."
Chris Huhne wins £1bn funding for carbon capture technology
Funding is half the sum originally requested but allays fears the coalition would drop costly commitment altogether
Allegra Stratton and Juliette Jowit guardian.co.uk, Monday 18 October 2010 19.29 BST
The energy secretary, Chris Huhne, has won a battle to secure £1bn from the Treasury to pay for the development of demonstration technology to capture and bury carbon emissions from power plants.
Although only half the sum requested by the Department of Energy and Climate Change (Decc), it allays environmentalists' fears that the coalition would drop the costly commitment altogether.
There is less good news for another plank of the green economy: the Treasury has apparently squeezed proposals for a green investment bank. Huhne wanted £6bn in public money to set up a bank – which was announced by the last Labour government and was a Tory manifesto commitment – that can unlock private sector funds by encouraging investment in risky green technologies.
It now seems likely that £2bn of money largely already pledged by the government for green projects will be corralled into a watered-down green fund. "It will look like a chunky announcement, in reality most of the money is there but it's being brought into one place," said an adviser to Decc.
In other spending areas there is mixed news, according to government sources:
• A 10% increase in money for nuclear decommissioning.
• £400m for the proposed renewable heat incentive for small-scaleprojects such as ground-source heat pumps.
• £60m funding to upgrade north-eastern ports critical for the go-ahead of factories building blades for wind turbines.
• A 10% cut to so-called feed-in tariffs – the subsidy for small renewable projects such as solar panels on houses.
The coalition hopes the package will help the prime minister in his claim to lead the "greenest government in history" and help the Lib Dems recover from their low poll rating. A recent YouGov survey showed threequarters of Lib Dem voters wanted clean energy spending protected or increased.
Developing carbon capture and storage (CCS) is seen as a vital step towards crafting an energy sector that will help Britain meet its legally bound target for reducing greenhouse gas emissions over the next 20 years. But the project requires up-front funding and there had been fears that the project would lose out in the comprehensive spending review on Wednesday. The Tory climate minister Greg Barker said in a speech last month that some "very good [low carbon] projects" would have to be scaled back.
Huhne is said by sources close to the process to have fought a tough fight to clinch extra funding. Despite joining the star chamber at the end of September – normally allowed once cabinet ministers settled their department's budgets with the Treasury – he battled right up until the close of play on Friday for key gains. He was supported by two Conservatives – the Cabinet Office minister, Oliver Letwin, and the junior Decc minister and former Tory treasurer, Lord Marland.
The Treasury will transfer the funds to Decc from the sale of assets, which surprised officials who expected all proceeds from asset sales to go towards paying down the deficit.
A party source said: "Chris fought really hard on CCS. He has not got all the money he wanted – only half that he argued for – but bear in mind the Treasury weren't going to give him anything."
Huhne has taken a serious hit on his programme budget. Warm Front, which provides grants for insulation and heating for the less well off, will get "slashed pretty bad" one observer said. There will be increased social price support - going from nothing presently to £300m - which will help reduce bills for poorer customers but it is unlikely to compensate for the upset caused by bringing an end to the programme and the Lib Dems expect to be attacked by Labour.
The original plan was for the UK to have four CCS demos, and there are still doubts about how the rest will be funded. The coalition had supported the Labour government's plan for four CCS demos but industry insiders had been concerned they would not go for a levy on bills to fund the remaining three because it would end up having to count towards the government expenditure tally. This appears to remain the case.
Other gains made by Huhne will – barring last-minute changes – include protecting the budget for nuclear decommissioning which, far from being ring-fenced as had been the original intention, was the target of Treasury cuts. Instead Huhne has secured an increase from £2bn to £2.2bn. There will also be the necessary funding to enable a £60m upgrade of ports in the north-east to go ahead, supporting multinational companies in locating windfarm factories nearby – something they couldn't do without the port upgrade.
The environmental community will be displeased that the government is to cut the subsidy to people sending their own energy back to the grid. It is not clear when the 10% reduction will come into effect.
Allegra Stratton and Juliette Jowit guardian.co.uk, Monday 18 October 2010 19.29 BST
The energy secretary, Chris Huhne, has won a battle to secure £1bn from the Treasury to pay for the development of demonstration technology to capture and bury carbon emissions from power plants.
Although only half the sum requested by the Department of Energy and Climate Change (Decc), it allays environmentalists' fears that the coalition would drop the costly commitment altogether.
There is less good news for another plank of the green economy: the Treasury has apparently squeezed proposals for a green investment bank. Huhne wanted £6bn in public money to set up a bank – which was announced by the last Labour government and was a Tory manifesto commitment – that can unlock private sector funds by encouraging investment in risky green technologies.
It now seems likely that £2bn of money largely already pledged by the government for green projects will be corralled into a watered-down green fund. "It will look like a chunky announcement, in reality most of the money is there but it's being brought into one place," said an adviser to Decc.
In other spending areas there is mixed news, according to government sources:
• A 10% increase in money for nuclear decommissioning.
• £400m for the proposed renewable heat incentive for small-scaleprojects such as ground-source heat pumps.
• £60m funding to upgrade north-eastern ports critical for the go-ahead of factories building blades for wind turbines.
• A 10% cut to so-called feed-in tariffs – the subsidy for small renewable projects such as solar panels on houses.
The coalition hopes the package will help the prime minister in his claim to lead the "greenest government in history" and help the Lib Dems recover from their low poll rating. A recent YouGov survey showed threequarters of Lib Dem voters wanted clean energy spending protected or increased.
Developing carbon capture and storage (CCS) is seen as a vital step towards crafting an energy sector that will help Britain meet its legally bound target for reducing greenhouse gas emissions over the next 20 years. But the project requires up-front funding and there had been fears that the project would lose out in the comprehensive spending review on Wednesday. The Tory climate minister Greg Barker said in a speech last month that some "very good [low carbon] projects" would have to be scaled back.
Huhne is said by sources close to the process to have fought a tough fight to clinch extra funding. Despite joining the star chamber at the end of September – normally allowed once cabinet ministers settled their department's budgets with the Treasury – he battled right up until the close of play on Friday for key gains. He was supported by two Conservatives – the Cabinet Office minister, Oliver Letwin, and the junior Decc minister and former Tory treasurer, Lord Marland.
The Treasury will transfer the funds to Decc from the sale of assets, which surprised officials who expected all proceeds from asset sales to go towards paying down the deficit.
A party source said: "Chris fought really hard on CCS. He has not got all the money he wanted – only half that he argued for – but bear in mind the Treasury weren't going to give him anything."
Huhne has taken a serious hit on his programme budget. Warm Front, which provides grants for insulation and heating for the less well off, will get "slashed pretty bad" one observer said. There will be increased social price support - going from nothing presently to £300m - which will help reduce bills for poorer customers but it is unlikely to compensate for the upset caused by bringing an end to the programme and the Lib Dems expect to be attacked by Labour.
The original plan was for the UK to have four CCS demos, and there are still doubts about how the rest will be funded. The coalition had supported the Labour government's plan for four CCS demos but industry insiders had been concerned they would not go for a levy on bills to fund the remaining three because it would end up having to count towards the government expenditure tally. This appears to remain the case.
Other gains made by Huhne will – barring last-minute changes – include protecting the budget for nuclear decommissioning which, far from being ring-fenced as had been the original intention, was the target of Treasury cuts. Instead Huhne has secured an increase from £2bn to £2.2bn. There will also be the necessary funding to enable a £60m upgrade of ports in the north-east to go ahead, supporting multinational companies in locating windfarm factories nearby – something they couldn't do without the port upgrade.
The environmental community will be displeased that the government is to cut the subsidy to people sending their own energy back to the grid. It is not clear when the 10% reduction will come into effect.
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