IPCC should have a role in developing methodologies for estimating SLCPs

Globally-applicable methods for short-lived climate pollutant emissions estimation are urgently needed

There is growing global interest in combatting short-lived climate pollutants (SLCPs, sometimes referred to as short-lived climate forcers or SLCFs) including methane, black carbon, and tropospheric ozone. They contribute to climate change and adversely impact human health, crop yields and the cryosphere.

SEI has been working with the Climate and Clean Air Coalition (CCAC) in developing approaches and tools to help improve air quality and protect the climate through actions to reduce SLCPs. The LEAP-IBC tool, developed by SEI, is being used by CCAC member countries to develop their SLCP emission inventories and mitigation strategies. However, globally-applicable SLCP emission inventory methods are currently lacking. SLCP emissions estimation (like those using LEAP-IBC) largely rely on European guidance and default emission factors that may not be relevant for other regions, especially in developing countries.

SEI represents the CCAC view on the need for authoritative guidance on estimating SLCP-relevant emissions at Intergovernmental Panel on Climate Change (IPCC) Expert Meeting (May 2018).

It is the CCAC’s view that the IPCC is the most appropriate body to take on the development of comprehensive and harmonised methods to help meet the growing demand from countries around the world for authoritative guidance on estimating SLCP-relevant emissions.

To help reflect this view, the CCAC nominated Harry Vallack and others to attend the IPCC Expert Meeting on Short-lived Climate Forcers held in Geneva, Switzerland, 28-31 May 2018. At the request of the CCAC’s Science Advisory Panel, Harry had previously led the development of a document entitled Addressing Black Carbon Emission Inventories along with Graciela Raga from the National Autonomous University of Mexico. To help promote the CCAC’s position, this document was then submitted and circulated prior to the Expert Meeting, with a presentation and other contributions also being made in support of the CCAC’s view during the meeting itself.

Positive result: The Expert Meeting agreed that the IPCC is the right organisation to develop and disseminate globally-applicable guidance on estimating SLCP-related emissions.

The outcome was very positive, with a broad consensus that internationally-agreed, globally applicable methodologies and emission factors for SLCF emission inventories are now required. Crucially, the meeting agreed that the IPCC is the right organisation to fill gaps in existing methodologies and to develop and disseminate an internationally-agreed, globally applicable methodological guidance based on existing methodologies. It also noted that this could be achieved in close cooperation and collaboration with other relevant international bodies including the CCAC.

The Expert Meeting report was well-received at IPCC’s 48^th session (Korea, October 2018). Additional proposals on future work on SLCFs requested from the TFI for discussion at IPCC’s next session.

The summary of the Expert Meeting was submitted to the IPCC’s 48^th session (held in Incheon, Korea, October 2018) where the co-chair of the IPCC’s Task Force on National Greenhouse Gas Inventories (TFI) proposed that their future work should include:

• convening an expert meeting to identify gaps in current SLCF inventory methodologies to help countries that wish to begin reporting national SLCF inventories; and
• developing a further work plan, including possible production of a new methodology report for SLCF inventories during the IPCC’s 7^th assessment cycle.

The 48^th session noted the TFI report on the expert meeting and requested additional proposals on future work on SLCFs from the TFI for discussion at the IPCC’s 49^th session. This is seen a very positive development in IPCC’s position that will hopefully lead to improved guidance for countries estimating their SLCP-related emissions and working out how best to reduce them so as to improve air quality and reduce short-term climate impacts globally.