As a result of substantial government support, Norway is more or less self-sufficient in its main agricultural products. This contributes to both trade distortions and higher greenhouse gas (GHG) emissions. In multinational negotiations separate efforts are being made to liberalize trade (through the World Trade Organization) and to reduce global GHG emissions (through the United Nations). Using a model of Norwegian agriculture, we explore interconnections between trade liberalization and GHG emission reductions. We show that the Doha proposals would involve no major cut in either agricultural production or GHG emissions due to weakness in the disciplines on trade distorting support. We contrast further trade liberalization and the use of a carbon tax to achieve emission reductions. Trade liberalization involves relatively large impacts on agricultural activity. Trade distortions decrease, and, economic welfare increases substantially due to lower production. For a high cost country like Norway, this indicates that the GHG abatement cost is negative in the sector if no value is attributed to agricultural activity beyond the world market price of food. A more targeted policy to reduce GHG emissions is to use a carbon tax. Compared to the trade liberalization case, both production and land use can be kept at a higher level with only a modest decrease in economic welfare. The side-effect is, however, higher trade distortions.