The OECD has suggested global net carbon emissions from agriculture, forestry, and other land uses can be cut hugely, with 41% of this coming from avoiding deforestation alone.
Just over quarter (28%) of the net emissions cut could come from controlling agriculture emissions, and 9% from soil carbon sequestration.
Agriculture and land use emission taxes, and subsidies for carbon sequestration, could reduce net emissions 89% in 2050, according to the study by the Organisation for Economic Co-operation and Development, the intergovernmental economic organisation of 37 countries founded in 1961 to stimulate economic progress and world trade.
The reduction represents 12% of manmade GHGs.
The OECD’s Policy strategies and challenges for climate change mitigation in the agriculture, forestry and other land use (AFOLU) sector study was compiled with a view to helping limit long-term global temperature increases to 1.5C and 2C.
A global carbon tax would be twice as effective in lowering emissions as an equivalently priced emission abatement subsidy.
But by raising agricultural production costs, emission taxes reduce global per capita calorie consumption by 2%-4% in 2050, and global agricultural output by 3%-8%.
Emission abatement subsidies avoid such impacts, according to OECD experts.
Taxes also raise revenues, while subsidies require government expenditures.
A shift to lower emission diets by consumers is assessed to have a much smaller impact on reducing agri-emissions than taxing these emissions, according to the study.
For example, lowering the content of livestock products in consumer diets (except in least developed countries and India) is not as effective as emission taxes.
Agriculture, forestry and other land use account for 23% of net global greenhouse gas (GHG) emissions, said the OECD, a share likely to grow without strong policy action to lower these emissions.
The organisation said agri-emission reduction progress has been gradual and piecemeal, against a backdrop of increasing urgency for action on climate change, but with concerns about potentially negative effects on food security and farmer livelihoods, particularly in least developed countries.
The OECD looked at how taxes on emissions from agriculture, land use, and forestry would compare with subsidies to reward carbon sequestration in forest biomass and agricultural soils.
It also examined abatement technologies in agriculture (such as dietary changes to reduce methane from ruminants, anaerobic digesters to reduce methane emissions from manure, practices to lower nitrous oxide from fertiliser use on crops, and drainage management to lower methane from rice production).
It was found the collective impact of emission taxes is about twice as large as that of abatement subsidies.
The single most effective measure found is a land-use change and forestry emissions tax, with relatively low impact on consumers and producers, by raising the cost of converting forests and other natural land to agriculture.
Avoiding deforestation alone generates 41% of new emission reduction, in the OECD proposal.
Most of this would come in Latin America, sub-Saharan Africa and, to a lesser extent, Southeast Asia.
Afforestation alone also makes a sizeable contribution (22%), particularly in Latin America.