Preliminary 2020 Global Greenhouse Gas Emissions Estimates
Understanding annual trends in greenhouse gas (GHG) emissions is a critical input for decision-makers in their efforts to reach net-zero emissions, whether is at the national, state, city, or corporate levels. Tracking emissions of the 190+ Parties to the Paris Agreement is an essential part of ensuring the effectiveness of global efforts to keep temperature rise well below 2° Celsius. A recent Washington Post investigation found that countries underreport emissions to the UN, leaving a considerable gap between reported emissions and actual emissions. The Post investigation found that inconsistencies in measurement and the frequency of reporting contributed to a gap of 8-13 gigatons of CO2e, which accounts for as much as 23% of global emissions.
While the Paris Agreement calls for improvements in the consistency and frequency of reporting, decision-makers need reliable data about the status of countries’ emissions now. To fill that gap, Rhodium Group provides the most up-to-date global and country-level GHG emissions estimates each year. This year’s update features final emissions estimates from 1990-2019 and preliminary estimates for 2020. This data includes estimates for all six Kyoto gases from across all sectors of the economy consistent with UN reporting guidelines. In partnership with Breakthrough Energy, Rhodium makes this data available through the ClimateDeck.
Total global emissions drop 4.4% in 2020 based on preliminary estimates
Based on our preliminary estimates for 2020, global emissions—including emissions of all six Kyoto gases, inclusive of land-use and forests and international bunkers—dropped from 52.4 gigatons of CO2e in 2019 to 50.1 gigatons in 2020 (Figure 1). This marks a 4.4% decline from 2019 levels, by far the largest drop in recorded history. The reduction in emissions in 2020 due to the COVID-19 pandemic and global recession was 10 times greater than the impact on emissions from the 2008 global financial crisis.
As we noted in our preliminary estimates of China’s 2020 emissions from earlier this year, China was one of the only major economies that saw emissions rise in 2020, by 1.4%. Because all other major economies saw economic contraction and an overall reduction of emissions in 2020, China’s overall share of global emissions grew in 2020, reaching 30% (Figure 2). The US and EU-27 both saw double digit declines in 2020 (10% and 11% declines, respectively), dropping their share of global emissions slightly from 2019. GHG emissions in India—the world’s 4th largest emitter at 6% of global emissions—declined just under 7% between 2019 and 2020.
Based on our preliminary estimates for 2020, China’s GHG emissions exceeded those of all the developed world combined (here defined as all OECD member states and all EU member states) for the second year in a row. Based on our final 2019 estimates, we find that China’s emissions narrowly exceeded the combined OECD + EU total by about 0.8% (Figure 3). In 2020—based on our preliminary estimates—that gap grew to over 13% as China’s emissions continued to grow and OECD + EU emissions dropped by just over 10%.
Industry and electric power generate more than half of global emissions
In 2019—the latest year for which there is sufficient data to provide sectoral level detail—industry remained the largest emitting sector, generating 30% of global emissions (Figure 4). Emissions from electric power generation contributed 26% of global emissions, the vast majority of which came from combustion of coal. Combined emissions from land use, agriculture and waste made up 21%, followed by transportation (16%) and buildings (7%).
All the datasets provided here are available in the ClimateDeck, as well as additional data and details, including the ability to filter by country, gas, and sector, as well as socioeconomic indicators (e.g., emissions per capita and per GDP), and full inventory tables for each country.
To estimate global and country-level GHG emissions, we take a bottom-up approach, which combines national inventories (where fully provided) with derived inventories (where national inventories are not provided or complete). For all Annex I countries, Rhodium’s GHG estimates match those of official national inventory data from 1990-2019. For non-Annex I countries, we calculate derived inventories using a combination of national activity data (e.g. fuel combustion, industrial production) with sector- and fuel-specific emission factors. This method provides annual GHG emissions based on changes in socioeconomic activity at the country and sector level and is appropriate for tracking trends in emissions and emissions intensity over time.
In addition to our historical inventories, this year we also provide preliminary estimates for global emissions in 2020 for all countries. We estimate energy CO2 using BP’s 2021 Statistical Review of World Energy. For other gases, we estimate 2020 emissions based on relevant national activity and socioeconomic data.
To quantify country-level fuel combustion emissions, we source all Annex I countries’ emissions from their most recent national emission reports to the UNFCCC (1990-2019). For most Non-Annex I countries, we derive our own estimates of energy-related emissions from IEA energy consumption flows (1990-2019) and IPCC emission factors. For 2020 estimates for all countries, we use growth rates derived from BP’s 2021 Statistical Review of World Energy.
Not all Non-Annex I countries’ energy consumption is accounted for in IEA’s energy flows (i.e. there are 40-50 countries—mostly small-island nations and African countries—who consume a small amount of energy relative to the rest of the world, and whose aggregate annual emissions are less than 100 Mt CO2). For these countries, we source emissions data from national reporting to the UNFCCC for available years and interpolate for years with no available data.
For fugitive emissions from oil and gas and coal mining, for most non-Annex I countries, we use IEA’s database of world fugitive emissions (2021).
To quantify country-level industrial process emissions (non-combustion sources), we source all Annex I countries’ emissions from the most recent national emission reports to the UNFCCC. We source Non-Annex I countries’ non-CO2 emissions from EPA (2019), and we derive their non-combustion CO2 emissions based on fuel combustion emissions and production data by industry sub-sector.
Agriculture and Waste
To quantify country-level agriculture and waste emissions (non-combustion sources), we source Annex I emissions from UNFCCC inventories and non-Annex I countries’ emissions from the UN Food and Agriculture Organization (FAO) (2021).
Land-use and Forests
To quantify country-level land-use, land-use change and forestry (LULUCF) emissions and removals, we source Annex I countries’ emissions from UNFCCC national emissions reports. We source Non-Annex I countries’ emissions from FAO (2021).