A 500-metre-tall block of ice with a footprint the size of New York City’s Central Park (4km by 0.8km) would weigh about 1.5 gigatonnes (Gt, or 1.5bn tonnes), about the same weight as 15 000 fully-loaded aircraft carriers – or the annual agricultural greenhouse gas (GHG) emissions of OECD countries in 2015-17. At 1.47 Gt of CO2-equivalent, it is up 3% vs. a decade earlier (1.42 Gt CO2eq). Globally, annual agricultural GHG emissions in the same period stood at c. 5.2 Gt of CO2eq: that same block of ice on Central Park would be almost 2km tall.
Agricultural GHG emissions come in the form of methane and nitrous oxides originating from organic and inorganic fertilisers. The annual variation of emissions in OECD countries stood at 0.25% between 2003-2005 and 2013-2015: Spain (-1.29%) and Greece (-1.16%) saw the biggest decreases in annual variations, while Turkey (3.04%) and Estonia (2.00%) saw the biggest increases.
Better environmental incentives and improved land-use policies are key. The potential for emissions reduction in the agricultural sector is high as abatement costs are typically lower than other sectors, but achieving this will require wide-scale adoption of different practices and methods. An expansion in the provision of agricultural support linked to biodiversity conservation efforts and the dissemination of training programmes through agricultural co-operatives and chambers of agriculture could make a big difference in GHG reduction efforts.