National Aeronautics and Space Administration

Forcings in GISS Climate Model

We summarize here forcing data used in the GISS global climate models in recent years.

Changes in Climate "Forcings"

The following figure shows changes in climate "forcings" or factors that have contributed to climate change since 1750.

These agents can be categorized into three areas: greenhouse gases, other man-made (anthropogenic) forcings, and natural forcings. The greenhouse gases consist of carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂0) and chlorofluorocarbons (CFCs). Other anthropogenic forcings consist of black carbon (soot, formed by incomplete combustion), reflective aerosols (tiny airborne particles that reflect sunlight back to space), soil or dust, land cover changes, and forced cloud changes. Natural forcings include changes of the sun's energy. Figure is also available in PDF format. (Source: Figure 28 of Hansen et al. 2005. See references below.)

Effective Forcings Employed in Current Climate Simulations

The following figures show effective global climate forcings employed in our current global climate simulations (e.g., Hansen et al. 2007a,b), relative to their values in 1880.

(a) The separate radiative forcing data are available in a table. The figure is also available as a PDF. (last modified: 2012/12/19)

(b) The net forcing figure is available as a PDF. (last modified: 2012/12/19)

Further Details and Various Future Scenarios to 2100

• Well-Mixed Greenhouse Gases (last modified: 2012/11/13)
• Solar Irradiance (last modified: 2004/04/03)
• H₂O (last modified: 2002/01/10)
• Tropospheric Aerosols (last modified: 2006/11/07)
• Stratospheric Aerosols (last modified: 2012/12/13)

Contacts

Please address scientific inquiries about these data to Dr. Makiko Sato.

Also participating in this research are Drs. Andrew Lacis and Reto Ruedy.

References

• Hansen, J., M. Sato, R. Ruedy, et al. 2005. Efficacy of climate forcings. J. Geophys. Res., 110, D18104, doi:10.1029/2005/JD005776. (See also Efficacy webpages).
• Hansen, J., M. Sato, R. Ruedy, et al. 2007. Climate Dynam., Climate simulations for 1880-2003 with GISS modelE. Climate Dynam., 29, 661-696, doi:10.1007/s00382-007-0255-8.
• Hansen, J., M. Sato, P. Kharecha, K. von Schuckmann, 2011. Earth's energy imbalance and implications. Atmos. Chem. Phys., 11, 13421-13449, doi:10.5194/acp-11-13421-2011.

This page was written by Dr. Makiko Sato. (Last modified: 2012/12/19)