The rate at which clean energy infrastructure can be built compared to the rate at which global demand for energy will grow make it now impossible to hold Global Warming below 2°C unless governments action a soil carbon sequestration strategy, according to leading climate scientists.
Scientists, including the world’s most famous Climate Change scientist, NASA’s James Hansen, agree that renewables will not be ready to supply the world’s energy demands for up to 50 years, if then. In Smart Solutions to Climate Change, Chris Green of McGill University and Isabel Galiana look at current rates of progress and conclude that by 2050 alternative energy sources will produce less than half the power needed to stabilise carbon emissions. By 2100, the gap would be even wider.
Australian scientists point to soil carbon as the solution: “It will be next to impossible for Australia to achieve the scale of [emissions] reductions required in sufficient time to avoid dangerous climate change unless we also remove carbon from the atmosphere and store it in vegetation and soils,” the Wentworth Group of Concerned Scientists told the recent Victorian Inquiry into Soil Carbon. Even the CSIRO agrees Dr Michael Battaglia, Theme Leader, Sustainable Agriculture Flagship, CSIRO told the inquiry: “What [soil carbon sequestration] actually gives us is time to make those adjustments [transition from burning coal].”
SIMPLY SETTING TARGETS for emissions reductions won’t slow down the process of climate change because it is your Grandfather’s emissions - the carbon released into the atmosphere 70 years ago - that are causing Global Warming. Luckily, we have the only process for Extracting billions of tonnes of CO2 every year for 50 years, fully deployed and scaled up, ready to start: Photosynthesis, in the form of 5.5bn hectares of farmland around the globe. Scientists such as soil carbon authority Professor Rattan Lal estimate the process can remove 3billion tonnes of CO2 annually for 50 years. He testified before the US Senate that soil carbon can be a “bridge to the future” that buys us time’.
James Hansen and Rattan Lal agree that the world’s farmers can draw down the CO2 equivalent of 50ppm and hold it for 50 years. With the globe racing towards 400ppm, hoping to stop it at 450ppm, soil sequestration is attractive and available and relatively cheap. It would forestall the need for deeper, faster cuts in the future and it would protect the economy from damage.
So why is it not activated immediately? Not all scientists understand soil carbon and some have conducted a long, very public campaign to convince governments and farmers that it is plagued by uncertainties and complexities such that its offsets are dangerous. The Victorian Inquiry duly concluded: “Due to the significant scientific and economic uncertainties associated with soil carbon sequestration, the Committee concluded that a cautious and conservative approach should be taken in establishing incentive mechanisms to encourage soil carbon sequestration in Victoria.”
The world does not have the luxury of time to be cautious and conservative, as soil scientist Professor Annette Cowie told the Victorian Committee: “I think the issue of climate change is so urgent that it would be a mistake to say we have to put this off to wait for better science. I do not think we need perfect science and perfect understanding to be able to start providing incentives for landholders to build soil carbon.” Professor Cowie is Director, National Centre for Rural Greenhouse Gas Research, University of New England.
Despite the Australian Government’s $46.5m Carbon Farming Initiative, soil carbon is stalled at the national level as well, as science makes its way towards a new round of three year trials.
“It can buy us the time we need, but that time is passing fast and won’t be for sale forever.”
REFERENCES:
“It will be next to impossible for Australia to achieve the scale of [emissions] reductions required in sufficient time to avoid dangerous climate change unless we also remove carbon from the atmosphere and store it in vegetation and soils.” – WENTWORTH GROUP OF CONCERNED SCENTISTS, Inquiry into Soil Carbon Sequestration in Victoria, Environment and Natural Resources Committee, Parliament of Victoria, September 2010
“A tonne of carbon avoided in emissions through not burning … coal is a much more secure way to reduce emissions than a tonne sequestered [in vegetation and soils].…what [soil carbon sequestration] actually gives us is time to make those adjustments.” - DR MICHAEL BATTAGLIA, THEME LEADER, SUSTAINABLE AGRICULTURE FLAGSHIP, CSIRO, Inquiry into Soil Carbon Sequestration in Victoria, Environment and Natural Resources Committee, Parliament of Victoria, September 2010
“The technical potential of carbon sequestration in world soils may be 2 billion to 3 billion mt per year for the next 50 years. The potential of carbon sequestration in soils and vegetation together is equivalent to a draw-down of about 50 parts per million of atmospheric CO2 by 2100.” - RATTAN LAL, “The Potential for Soil Carbon Sequestration” in Agriculture and Climate Change: An Agenda for Negotiation in Copenhagen, International Food Policy Research Institute, 2009.
The authors discredit the notion of "geo-engineering" solutions, noting that with present cost estimates the price of artificially removing 50 ppm of CO2 from the air would be about $20 trillion. They suggest instead that improved agricultural and forestry practices offer a more natural way to draw down CO2, noting that reforestation of degraded land and improved agricultural practices that retain soil carbon could draw down atmospheric CO2 by as much as 50 ppm. JAMES HANSEN
Hansen, J., Mki. Sato, P. Kharecha, D. Beerling, R. Berner, V. Masson-Delmotte, M. Pagani, M. Raymo, D.L. Royer, and J.C. Zachos, 2008: Target atmospheric CO2: Where should humanity aim? Open Atmos. Sci. J., 2, 217-231, doi:10.2174/1874282300802010217.
“C sequestration in terrestrial biosphere (e.g., forests, agricultural soils) is considered a low-hanging fruit, a win-win strategy, and a bridge to the future until low-C or no-C fuel sources take effect. In contrast to the engineering techniques of CO2 capture and injection.” – RATTAN LAL, Editorial / Soil & Tillage Research 96 (2007) 1–5
“It is true that soil C sequestration is a short-term solution to the problem of gaseous emissions. In the long term, reducing emissions from the burning of fossil fuels by developing alternative energy sources is the only solution. For the next 50 years, however, soil C sequestration is a very cost-effective option, a “bridge to the future” that buys us time in which to develop those alternative energy options.”Dr Rattan Lal, Testimony before US Senate Committee on Environment and Public Works, Washington, D.C., 8 July 2003
SOIL CARBON SEQUESTRATION BY AGRICULTURE AND FORESTRY LAND USES TO MITIGATE CLIMATE CHANGE FOR A HEARING ON THE POTENTIAL OF AGRICULTURAL SEQUESTRATION TO ADDRESS CLIMATE CHANGE
“Carbon sequestration can buy us time - estimated to as much as 50 years - to develop and deploy new technology that can radically reduce greenhouse gases without being an economic killer. It can buy us time because it slows the rate of CO2 accumulation and could even reduce the gas currently trapped in the atmosphere even without immediate emissions reductions. In this way, carbon sinks lead us to real reductions because the only way the U.S. will take part in a global treaty is if the means are available to reduce these gases without crippling our economy.” U.S. Sen. Sam Brownback – KS, Equity and Global Climate Change Conference, Washington D.C., April 18, 2001
‘But Follett* says that ARS is doing this research to buy time—up to 25 years or more—for the technologies to be developed to minimize those emission.’
"We say 25 years because our estimates show it'd take that long before the soil's ability to store carbon would begin to level off, decreasing the benefits of more carbon storage," "Depositing Carbon in the Bank: The Soil Bank, That Is" was published in the February 2001 issue of Agricultural Research magazine.
*Dr Ron Follett – USDA Agricultural Research Service
“There are estimates that terrestrial ecosystems could sequester significant quantities of carbon over the next 50 years. The impact of this sequestration could help buy time for other technologies to come on-line by delaying the need for more dramatic decreases in global emissions.” Roger C. Dahlman* and Gary K. Jacobs*,“Research Challenges for Carbon Sequestration in Terrestrial Ecosystems” In Proceedings of a Symposium on CO2 Capture, Utilization and Sequestration. American Chemical Society National Meeting Washington DC August 20, 2000 * U.S. Department of Energy
