State of Our Climate
Atmospheric Greenhouse Gas Concentrations
CO2 equivalent
Atmospheric GHG concentrations all together are expressed as CO2 equivalent. It tells us we are 'committed' (locked in) to a higher warming than at present. Radiative (hear) forcing is derived from CO2 eq.
800,000-year
ice core limits
CO2: 300 ppm
methane: 800 ppb
nitrous oxide: 300 ppb
April 2023
CO2: 420.4 ppm
methane: 1,920 ppb
nitrous oxide: 336 ppb
Pre-industrial levels
CO2: 278 ppm
methane: 722 ppb
nitrous oxide: 270 ppb
CO2 equivalant
(all GHGs)
May 2022
508 ppm (CO2 eq.)
All three atmospheric GHGs are record high increasing at record rates, methane explosively
Past 800,000 yrs
Past 2,000 yrs
From 1800
(seasonally adjusted mean)
50% increase
266% increase
Explosive increase since 2019
From Scripps CO2: record for past week and up to 800,000 years ago
Note the concentration here is for the day- not the adjusted CO2 mean that is used for climate assessment
The (accelerating) concentration of all atmospheric greenhouse gases combined (CO2 equivalent) constitute a full long term equilibrium warming of over 2.5°C (Constant composition commitment)
There will be additional warming from the many large planetary feedback sources (like wetlands and permafrost)
There will be additional warming due to reduced efficiency of the land (forest) and ocean carbon sinks that have had the effect of buffering the warming by about 50%.
Another source of extra warming results from fossil fuel air pollution cooling, a hidden source of warming on termination of fossil fuel energy