Atmospheric GHG concentrations correlate directly with radiative forcing, which shows how the total heat in the climate system increases-a much better indicator than surface temperature increase alone.
Compared to 800,000 year ice core limit, the the total heat in the climate system from heat radiation of the three greenhouse gases is extremely high.
Research suggests there is more heat in the climate system today than the past 15 million years.
The atmospheric greenhouse concentrations show:
The NOAA atmospheric GHG graphs cover slightly different time periods. Here are the graphs corrected to the same time frame.
This shows that methane is increasing at a slightly slower rate than carbon dioxide. Nitrous oxide is increasing slightly faster.
The GHGs are increasing in the atmosphere at an unprecedented (never happened before) rate. The recent rate of change is dramatic and unprecedented; increases in CO2 never exceeded 30 ppm in 1,000 years – yet now CO2 has risen by 30 ppm in just the last 17 years… IPCC 2007 FAQ 7.1.
Therefore heat energy is being added to the climate system at an unprecedented rate – warming up the oceans, rapidly melting planetary ice, and increasing the temperature of Earth’s surface.
Atmospheric greenhouse gases August 2012
The US National Oceanic and Atmospheric Administration (NOAA) provides monthly atmospheric greenhouse gas concentrations.
These directly reflect the increase in the radiative forcing (heat energy content) of the atmosphere which is the most accurate measure of the heat added to the climate system.
State of the Climate 