How do we know what the sources of greenhouse gas emissions are? 

Countries report their greenhouse gas emissions to the United Nations Framework Convention on Climate Change. These reports are developed according to reporting guidelines adopted at the COP and methodologies laid out by the IPCC.

Now, for the first time in 13 years, the IPCC just updated guidance on how countries estimate and report their greenhouse gas emissions to the United Nations. Produced by the Task Force on National Greenhouse Gas Inventories (TFI), with the support of 280 experts from around the world, the new guidelines—which are expected to be agreed to at COP 25 later this year in Chile—will be a key reference for countries producing national greenhouse gas inventory reports. The changes made are more tweaks than a major overhaul, taking into consideration the latest scientific updates and technical breakthroughs.

This new methodological guidance (the "2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories") is one of the three IPCC reports to be released this year. The other two upcoming reports on Ocean and Land Use will be more policy-oriented.  

This guidance will prove to be a significant tool for countries to provide improved, reliable information about their activities and how their domestic efforts contribute to the global effort to combat the climate crisis. The result will be a sharper image of where global emissions come from—giving us, in turn, a better idea than ever of what we need to do to reduce greenhouse gas pollution.

So, What's New?

The"Refinement" updates, supplements and elaborates existing guidelineswhere gaps or out-of-date science have been identified. It does not revise the 2006 IPCC Guidelines, but will be used alongside them.

The "Refinement" will comprise five volumes following the same format of the 2006 IPCC Guidelines: one on general guidance and reporting, and four others on key sectors (Energy; Industrial Process and Product Use; Agriculture; Forestry and Land Use; and Waste).

The first volume includes a new chapter, which provides a better description on how to implement a national inventory management system by ensuring continuous improvement and generating more accurate data. This chapter is guided by and refers to the latest decisions adopted at COP24 in Katowice in December 2018, especially the requirements for a national improvement plan on transparency under the Paris Agreement's Enhanced Transparency Framework. It also builds on extensive practical experience in developing MRV systems (for GHG inventories) over the past few years.

That first volume also aims to strengthen data collection, especially for developing countries still struggling to gather and manage national data. There is new guidance for the development of country-specific emission factors and the collection of activity data, which are needed to better understand the relationship between emissions and their sectoral sources. Additionally, the new guidance provides suggestions for integrating GHG emissions reported from private facilities into national GHG inventories (in view of the increasing role companies play in providing data and reducing their carbon footprints). 

The main changes in the rest of the "Refinement" aim to improve the quality of the measurements, reporting and verification procedures in the various sectors of the economy. Advancements in science and technology will result in improved measurements, reporting and verification in several areas, including fugitive emissions from oil and natural gas systems; countries' ability to measure efforts to comply with the Montreal Protocol to reduce ozone pollution; and estimation of carbon emissions and removals from the agricultural, land use and forestry sector. (The guidance on the agricultural, land use and forestry sector—which has proven difficult to measure—will affect our understanding of about a quarter of all emissions.)

The Paris Agreement expects countries, especially developing countries, to report on a broader range of greenhouse gases -- for instance, many developing countries currently only monitor and report on carbon dioxide, methane and nitrous oxide, while excluding fluorinated compounds and associated efforts to reduce the carbon footprint of air conditioning and refrigerants.   

The 2019 "Refinement"will provide countries with the means to improve their national estimates. While, in some countries, this could lead to reported estimates that will show an increase in the volumes of greenhouse gases emitted annually, it would also provide better data to inform many countries' decision making.

Sectors Types of changes Area affected by the changes
Energy Update/Elaboration
  • Emissions estimates from exploration and CO2 emissions (coal mining)
  • Emission factors representative of current practice on fugitive emissions from oil and gas. Additional guidance included for unconventional oil and gas production and abandoned wells.
  New guidance
  • New section on abandoned surface coal mines and on fuel transformation.
Industrial Processes and Product Use Update/Elaboration
  • Emission factors for dual pressure technologies for nitric acid; for fluorinated compounds production, including refrigeration and air conditioning; and for semiconductor industry.
  • Additional examples, “recipe-style” guidance on how to launch the ozone depleting substance substitutes inventory; elaborate the reference to the Montreal Protocol.
New guidance
  • Emissions from hydrogen production
  • Emissions (PFCs and CO2) from production of rare earth elements, textile industry, water proofing electronic circuit boards.
Agriculture, Forestry and Land Use Update/ Elaboration
  • Default values for dead organic matters, soils, N2O from cropland, rice cultivation, wetland, grassland.
  • Management of inter-annual variability
  • Assessment of completeness, time series, Quality Assurance/Quality Control, and reporting and documentation
  • Description and assessment of emissions from livestock and manure management and harvested product.
New guidance
  • Emission in biomass carbon stocks
  • Integration and use of remotely-sensed data, ground based data and ancillary data for more consistent estimates of land use sector
Waste Update/ Elaboration
  • Emission factors for incineration and open burning of waste
  • Default data on municipal solid waste generation, management and disposal
  • Uncertainty assessment
  • Emission in wastewater treatment and discharge
New guidance
  • Waste composition, methodologies

What's Next?

In the coming months, countries need to familiarize themselves with the 2019 supplemental guidelines and their implications. Interim climate negotiations in Bonn, Germany this June will provide a first opportunity for countries to review the updated methodology and explore how to best build capacity to put into it into practice. It is expected that the use of the 2019 "Refinement" in the context of the Paris Agreement's transparency framework will then be agreed upon at COP25 climate summit in Santiago, Chile this December.

Moving forward, to fulfill their binding requirements, and maintain trust, countries will need to regularly and transparently report how they add or subtract various emissions estimates to come up with a national total. They should also disclose which methodologies they use (as they transition to using or not the latest 2019 refinement) and how they account for traded emissions. All of this will be guided by accounting and transparency rules—many of which have been adopted at COP24 last year. But there are still outstanding accounting rules, and reporting decisions—especially on the use of market mechanisms—which are critical to make sure that what the atmosphere sees and what countries include in their reports are the same.