In 2016, ‘Controlling non-CO2 greenhouse gases’ was included in the the
13th Five Year Plan (2016-2020) outline. Then, last March, the 14th Five
Year Plan (2021-2015) outline went further, saying China would ‘strengthen
controls on other greenhouse gases such as methane, hydrofluorocarbons
and carbon tetrafluoride’.
But how will that be done? At a seminar on methane held in March 2021,
Li Gao, head of the Ministry of Ecology and Environment’s Department of
Climate Change, explained that the 14th Five Year Plan period will see
China produce action plans for controlling methane, with new policy,
technology and standards introduced in sectors including oil and gas, coal
and waste. Market mechanisms will also be used to encourage emissions
cuts.
More accurate data needed
A lot of work is still needed on the basics. The priority areas will be
monitoring, calculating, reporting and verifying methane emissions in key
sectors, such as energy, agriculture and waste.
Globally, methane data is obtained more by calculation than by actual
measurement. Sample monitoring is carried out at emission sources, with
the data obtained used to calculate average ‘emission factors’, and then
national methane emissions. This is known as bottom-up calculation. Top-
down calculations, on the other hand, use satellites, airplanes, drones and
vehicles to monitor methane at the country, regional or facility level.
But research shows that neither method is adequate, and there is room to
improve the quality and coverage of data.
Between 90% and 95% of China’s methane emissions in the energy sector
come from coal mines. For the 2014 National Greenhouse Gas Emissions
Inventory, the most recent to be made public, China used default emission
factors provided by the IPCC in 1996 to calculate methane emissions from
open-air coal mines. To calculate emissions from abandoned mine shafts,
China used the IPCC’s simplest methodology and simplified assumptions.
But Teng Fei says these factors and methodologies may not be suitable in
China – and any inaccuracies will have a big impact on the overall data.