Probability distribution functions (PDFs) of climate forcings from man-made pollution, including greenhouse gases (red), direct and indirect effects of aerosols (blue), and the total man-made forcing (black dashed). The width of each distribution indicates the range of uncertainty in the forcing, so the amount of climate forcing from greenhouse gases is known much more accurately than the amount of forcing from aerosols. The total man-made climate forcing in Watts per square meter is positive and leads to warming. Note that surface albedo, contrails and stratospheric water vapour forcings are included in the total forcing but not in the others, and natural forcings (solar and volcanic) are not included in these three PDFs. (Source: IPCC AR4 Figure 2.20b)
 |
The Skeptical Science website by Skeptical Science is licensed under a Creative Commons Attribution 3.0 Unported License. |