1. Ministry of Food Agriculture and Fisheries Danish Institute of Agricultural Sciences Options for reducing the greenhouse gas emissions from agriculture Jørgen E. Olesen

2. Ministry of Food Agriculture and Fisheries Danish Institute of Agricultural Sciences Greenhouse gases and international commitments Carbon dioxide (CO 2 ), methane (CH 4 ), nitrous oxide(N 2 O) and CFC gases are the most important greenhouse gases causing global warming. The Climate Convention from 1992 commits industrialised countries to stabilise their emissions of greenhouse gases. The Kyoto Protocol from 1997 is an international agreement on reduction of greenhouse gas emissions through a number of mechanisms. EU must reduce the emissions by 8% and Denmark by 21% before 2008/12.

3. Ministry of Food Agriculture and Fisheries Danish Institute of Agricultural Sciences Greenhouse gas emissions from Denmark Emissions in mill. ton CO 2 -equivalents per year The greenhouse gases have different global warming potentials: The global warming potential of methane (CH 4 ) is 21 times greater than CO 2 The global warming potential of nitrous oxide (N 2 O) is 310 times greater than CO 2

4. Ministry of Food Agriculture and Fisheries Danish Institute of Agricultural Sciences Fulfilling the Kyoto targets It is the objective of the Danish government that the commitments are distributed between sectors in a balanced way. Initiatives for reducing emissions are evaluated on their cost-effectivness against a benchmark of 120 DKK per ton CO 2. The emissions from the energy sector and some other industries are regulated by tradable quotas. Sectors without quotas (including agriculture) will also need to reduce emissions. Otherwise there will be a need to tighten the quotas for the energy sector.

5. Ministry of Food Agriculture and Fisheries Danish Institute of Agricultural Sciences Greenhouse gas emissions from Danish agriculture

6. Ministry of Food Agriculture and Fisheries Danish Institute of Agricultural Sciences Development in agricultural emissions of N 2 O og CH 4 The Aquatic Action Plans have led to a total reduction in nitrous oxide emissions of about 2.2 mill. ton CO 2 -eq per year Effect of Aquatic Action Plans

7. Ministry of Food Agriculture and Fisheries Danish Institute of Agricultural Sciences Model estimated carbon content in Danish mineral soils The changes around 1990 are caused by a ban on field burning of straw

8. Ministry of Food Agriculture and Fisheries Danish Institute of Agricultural Sciences Reduction of greenhouse gas emissions

9. Ministry of Food Agriculture and Fisheries Danish Institute of Agricultural Sciences Reduction of greenhouse gas emissions

10. Ministry of Food Agriculture and Fisheries Danish Institute of Agricultural Sciences Cost-effective reduction measures

11. Ministry of Food Agriculture and Fisheries Danish Institute of Agricultural Sciences Biogas Energy production (electricity and heat - substitution of fossil energy sources – depends on addition of other organic energy sources) Reduced methane emissions (requires collection of methane after the biogas reactor) Reduced nitrous oxide from the manure after field application The emissions can be reduced by 1.3 to 2.3 mill. ton CO 2 -eq/yr if all animal manure and organic wastes are used (depending on technology)

12. Ministry of Food Agriculture and Fisheries Danish Institute of Agricultural Sciences Cover on manure storages The methane oxidation in the slurry surface crust is increased at increasing methane concentration (a cover will increase the methane concentration and therefore the oxidation) Covers on slurry stores are estimated to reduce emissions by 10-50%. However, an optimised air exchange may further improve methane oxidation An airtight cover on solid manure heaps can virtually eliminate emissions of methane and nitrous oxide

13. Ministry of Food Agriculture and Fisheries Danish Institute of Agricultural Sciences Frequent manure removal from the animal house Daily removal of slurry from the house to an outside store will reduce the storage temperature (in particular during winter) and thus the methane emissions. Daily removal from dairy housing will reduce emissions by up to 50%.

14. Ministry of Food Agriculture and Fisheries Danish Institute of Agricultural Sciences Conclusions Methane and nitrous oxide are the most important greenhouse gas emissions from agriculture The emissions of methane can be reduced by improving cattle feeding and manure handling The emissions of nitrous oxide can be reduced by reducing N losses and improving manure and fertiliser management The cost-effective reduction measures reduce the emissions of several greenhouse gases simultaneously. Few measures have costs of less than 120 DKK per ton CO 2 The reduction of greenhouse gas emissions should be part of good agricultural practice (green accounting).