The previous chart shows the big picture of the Earth's energy imbalance. This chart focuses on the impact of the crucial greenhouse gases on the big picture. It shows the impact estimates of the monthly change in the energy balance caused by the three main greenhouse gases, CO2 (carbon dioxide), CH4 (methane) and N2O (nitrous oxide). The impact comes from the increase in the greenhouse gas concentrations from the pre-industrial levels.
Greenhouse gases absorb the energy that the Earth should be radiating back into space, like a blanket that warms the Earth. You can see this in the reduction of the blue area in the Earth's Energy Imbalance chart. The rise in the concentration of greenhouse gases since the pre-industrial levels has reduced the rate of radiated energy by about 3W/m2.
There are many other factors that impact the Earth's energy balance, such as changes in the sun's intensity, the Earth's albedo, halogenated gases, water vapor, ozone and aerosols like sulfur dioxide. We are looking for the data and calculations to show you about those impacts too.
The IPCC estimates the impact of many such factors as part of their study on radiative forcing.IPCC AR5 Synthesis Report
The impact is expressed in Watts per square meter (W/m2) to allow it to be compared to the energy balance of the Earth. The values are an estimate of the reduction of the Earth's radiated energy.
You can see a steady rise in the impact for all three main greenhouse gases. The chart also shows the relative impacts of the greenhouse gases compared to each other.
We combine three data sets with atmospheric gas concentrations to calculate the impact on the energy imbalance (radiative forcing).
The calculations are from the Meinshausen et al. (2020) paper 'The shared socio-economic pathway (SSP) greenhouse gas concentrations and their extensions to 2500'.
Atmospheric concentration data for carbon dioxide, methane and nitrous oxide are from the NOAA Global Monitoring Laboratory.
gml.noaa.gov CO2 concentrations
Credits: Ed Dlugokencky and Pieter Tans, NOAA/GMLUpdate cycle: monthlyDelay: ~ 1 week
gml.noaa.gov Methane concentrations
Credits: Ed Dlugokencky, NOAA/GMLUpdate cycle: monthlyDelay: 3 months
gml.noaa.gov Nitrous Oxide concentrations
Credits: Ed Dlugokencky, NOAA/GMLUpdate cycle: monthsDelay: 3 months
gml.noaa.gov Nitrous Oxide combined concentrations
Credits: Combined Nitrous Oxide data from the NOAA/ESRL Global Monitoring Division.Update cycle: several monthsDelay: 2 months
Reference: Meinshausen, M., Nicholls, Z. R. J., Lewis, J., Gidden, M. J., Vogel, E., Freund, M., Beyerle, U., Gessner, C., Nauels, A., Bauer, N., Canadell, J. G., Daniel, J. S., John, A., Krummel, P. B., Luderer, G., Meinshausen, N., Montzka, S. A., Rayner, P. J., Reimann, S., Smith, S. J., van den Berg, M., Velders, G. J. M., Vollmer, M. K., and Wang, R. H. J.: The shared socio-economic pathway (SSP) greenhouse gas concentrations and their extensions to 2500, Geosci. Model Dev., 13, 3571–3605, https://doi.org/10.5194/gmd-13-3571-2020, 2020.