Greenhouse Gases Can Be Confusing

When greenhouse gas concentrations are reported, sometimes only CO2 is reported, the dominant greenhouse gas, but to be complete, the non-CO2 gases must be reported also. Sometimes greenhouse gas concentrations are reported as tons of carbon or as tons of CO2 or as tons of CO2 equivalent.

Global Greenhouse Emissions of CO2 Only & Reported As Million Metric Tons of Carbon, Not CO2

Global carbon emissions * 3.67 = CO2 emissions. 1 million metric tons * 1,000 = 1 billion tons = 1 gigaton. Does not include non-CO2 greenhouse gas emissions.

Global Greenhouse Emissions of CO2 + CH4 + N2O + F-Gases & Reported

As GtCO2-eq (Gigatons of CO2-equivalent)

From IPPC AR6 WGIII Report. A gigaton = a billion metric tons.

Greenhouse Emissions (CO2 + non-CO2) by Continent As GtCO2-eq (Gigatons of CO2-equivalent)

From IPPC AR6 WGIII Report. A gigaton = a billion metric tons.

Atmospheric greenhouse gas concentrations are typically reported as only CO2 ppm (parts per million). But non-CO2 gases can be included if they are estimated as CO2-equivalent ppm.

Atmospheric Concentrations of CO2 + Non-CO2 Greenhouse Gases as CO2-Equivalents

Annual Greenhouse Gas Index is the relative warming influence of atmospheric greenhouse gases compared to 1990. The AGGI in 2021 was 1.49, which means that we’ve turned up the warming influence from greenhouse gases by 49% since 1990.

Projections of greenhouse gas emissions are typically reported as GtCO2-eq (Gigatons of CO2-equivalent), to account for both CO2 and non-CO2 greenhouse gases.

From IPPC AR6 WGIII Report. A gigaton = a billion metric tons.

Reduced greenhouse gas emissions from mitigation are typically reported as GtCO2-eq (Gigatons of CO2-equivalent), to account for both CO2 and non-CO2 greenhouse gases.

From IPPC AR6 WGIII Report. A gigaton = a billion metric tons.