Revised estimates for UK greenhouse-gas emissions has increased emissions in 2012 by around 10Mt C02e and in 1990 by around 29MtC02e, according to the government.
The energy and climate change department (Decc) is due to publish its full statistical release for greenhouse-gas emissions between 1990 and 2012 on 3 February.
Ahead of this, the department has set out the methods and data used to estimate these emissions, which it revises annually in response to new data or changes to international reporting guidelines.
The latest data will incorporate emissions from UK composting and nitrous oxide use in anaesthesia, in line with new reporting guidelines from the Intergovernmental Panel on Climate Change. Emissions from nitrogen triflouride (NF3) gas have also been included for the first time, though UK emissions of this are low, Decc says.
New global warming potentials (GWPs) for each gas have been updated according to those published in the IPCC’s fourth assessment report. GWPs allow each gas to be put in the same context by indicating its impact relative to carbon dioxide. The GWP for methane has, for example, been raised from 21 to 25, while that of nitrous dioxide has reduced from 310 to 298.
Emissions from agriculture have increased by around 3MtCO2e in both 1990 and 2012 due to new data on the average weights of dairy and beef cattle, manure management practices on UK farms, and the total area of organic soils.
Revised information on areas of cropland with (comprising?) organic soils that have been drained for agricultural use has resulted in an increase of emissions from land use change by around 4MtCO2e across the time series.
New sources of emissions have been added in line with the increased scope of the EU emissions trading system from the start of 2013, such as chemical flaring at ethylene plant. Fugitive emissions from gas and oil extraction have been revised to include venting from the gas distribution network and better estimates of emissions from small coal mines, Decc says.