A new study in the journal Science is going to complicate a mission by dozens of farm-state lawmakers to eliminate part of the EPA's proposed biofuel rules.
In the study, researchers from the Department of Energy's Pacific Northwest National Laboratory and the University of Maryland compared the impact of two types of climate polices on land use: one that limits carbon dioxide emissions from fossil fuels and industry only, and a second that limits emissions from fossil fuels, industry and changes in the land.
Their conclusion, vividly displayed in the graphs below: Policies that ignore terrestrial emissions while capping fossil fuel emissions will lead to widespread deforestation, increase global carbon emissions and will actually hurt farming in the future.
The EPA considered those potential impacts when it proposed a Renewable Fuel Standard last month that would measures biofuels' lifecycle emissions – including indirect land-use changes, such as the emissions generated by the clearing of Amazon rainforest for farms to make up for cropland lost to corn ethanol production in America.
At that depth of lifecycle accounting, corn ethanol's emissions are on par with gasoline, which is why the farm state congressmen are so upset.
Minnesota Democrat Collin Peterson, chairman of the House Agriculture committee, has gone so far as to threaten to hold the Waxman-Markey climate bill hostage to force changes in the fuel standard. Peterson and 46 co-sponsors are pushing a bill, dubbed the Renewable Fuel Standard Improvement Act, that would eliminate land use changes from lifecycle emissions accounting.
The study's findings suggest that Peterson's bill would be a mistake.
Instead, the authors recommend that governments put a comparable value on both types of carbon emissions – those related to fossil fuel use and those related to land use.
Land use impacts emissions in two major ways: Forests are valuable carbon sinks, currently absorbing about one-fifth off the world's greenhouse gas emissions, and deforestation currently accounts for about 20 percent of the human contribution to global greenhouse gas emissions.
If the world caps its energy-related carbon emissions without considering emissions related to land use changes, bioenergy crops will balloon, creating land competition for food production, and coming close to wiping out unmanaged forests by the end of this century, the researchers write. They explain:
"Several research studies have shown that the outcome of imposing a mitigation regime that only values carbon from energy and industrial sources creates incentives to increase bioenergy."
"As the use of bioenergy increases, land uses shift from food and fiber crops, forests, and unmanaged ecosystems to dedicated biomass crops. This in turn increases terrestrial carbon emissions globally—a perverse result of curbing energy and industrial emissions."
That has "profound implications for forests, crop and livestock prices, diet, the global energy system, and the cost of meeting environmental goals."
The researchers used computer models that drew in economics, energy, agriculture, land-use changes, and greenhouse gas emissions. They assumed the population would continue growing and that its standard of living, food and land needs, and technological skills would increase over time. They also assumed that energy technologies would include carbon capture and storage (CCS), nuclear, wind, solar, and geothermal power, and better energy efficiency in buildings and transportation.
The target was to keep carbon emissions below 450 ppm, considered the limit to keeping global warming below 2 degrees Celsius and avoiding catastrophic climate change.
Their graphs tell the story best.
The top graph shows a scenario that values terrestrial carbon emissions the same as carbon emissions from energy and industry.
Under that equal value scenario, "deforestation is replaced by afforestation, crop prices rise, purpose-grown bioenergy becomes an important agricultural product, and people shift away from consumption of beef and other carbon-intensive protein sources. Further, the total cost of limiting atmospheric CO2 concentrations is reduced."
Bioenergy remains important but not overwhelmingly so, and crops are more productive because they aren't pushed onto marginalized land. Land prices are higher, however, particularly for energy-intensive agriculture, such as livestock production. The impact would be a drop in beef consumption, which frees up more land and reduces greenhouse gases in the process.
The bottom graph shows a scenario in which only emissions from fossil fuels and industry are taxed.
"Placing an increasingly stringent tax on only the fossil fuel and industrial carbon emissions without placing any corresponding tax on terrestrial carbon causes land-use change emissions to increase to a peak greater than 10 Pg C [petagrams, or billion metric tons, of carbon] per year, as lands are converted to meet the growing demands for purpose-grown bioenergy crops in a growing but decarbonizing energy system."
"The increased demand for bioenergy crops pushes land requirements beyond traditional croplands and into lands that are increasingly less productive, requiring increasing quantities of land to grow each successive unit of agricultural product. The result is ... virtually all land that is not required for growing food and forest products is used for growing bioenergy."
With that second scenario, by the end of the century demand for biomass would be four times higher than under business as usual, the researchers write.
"Such grand-scale deforestation is hard to imagine in reality, because it is hard to imagine that society would find this result acceptable."
Land is already being lost to biofuel production and livestock at an alarming rate. Foreign companies are buying or leasing vast chunks of land, largely in Africa, with up to 50 million acres sold off or soon to be, according to report from the Washington, D.C.-based International Food Policy Research Institute.
In Bonn, Germany, over the next two weeks, international climate treaty negotiators preparing for the December summit in Copenhagen will be discussing ways to deal with deforestation and the increasing carbon emissions from land-use changes.
One leading proposal is the UN's Reducing Emissions from Deforestation and Degradation, or UN-REDD, which would allow landowners to earn valuable credits for preserving forest land through an emissions offset program. Voluntary offsets for reforestation are already in use, but at low volume and value. UN-REDD has the potential to increase that value to something closer to what the study's authors recommend.
That plan has problem, as well, though.
Interpol believes a growing market for forestry offsets would become a prime target for fraud and organized crime, agency environmental crime official Peter Younger told Reuters, and Papua New Guinea has already had to suspend its plans to sell rainforest carbon rights after deals began sparking land ownership disputes.
Friends of Earth-UK also released a report this week criticizing all pollution offsets, saying that increasing the opportunities for polluters to pay for projects such as hydropower in Asia or reforestation in Africa so the companies can keep polluting at home is making it impossible for industrialized countries to meet their pollution reduction targets.
Offsets tend to be "profoundly unjust" and "fundamentally flawed," the group writes. Allowing polluters to pay for forest preservation, for example, would spark a "land grab" that would put local indigenous communities at risk, and it would merely shift rather than prevent deforestation.
The Pacific Northwest National Laboratory/University of Maryland study offers no recommendation for how best to comparable value on terrestrial emissions and fossil fuel emissions. The authors write:
"The development of methods for conveying carbon values to land-use decision-makers could substantially improve the environmental effectiveness of global carbon emissions limitation systems. Improved land-use management and improved agricultural practices could reduce upward pressure on crop prices and the cost of emissions mitigation. However, the allocation of scarce land resources to competing ends will remain a major challenge for the 21st century."