HomeAboutActivitiesMapsPhotosPublicationsNews
 
Home >> Vital Climate Change Graphics Update >> Current and past radiative forcing, from human and natural causes
File type Download Size Language
.jpg .jpg Download 98 kb -
.pdf .pdf Download 716 kb -
.png .png Download 218 kb -
Uploaded on Tuesday 21 Feb 2012 by GRID-Arendal

Current and past radiative forcing, from human and natural causes

Year: 2005 Author: Philippe Rekacewicz, UNEP/GRID-Arendal
Description:
The radiative forcing from the increase in anthropogenic greenhouse gases since the pre-industrial era is positive (warming) with a small uncertainty range; that from the direct effects of aerosols is negative (cooling) and smaller; whereas the negative forcing from the indirect effects of aerosols (on clouds and the hydrologic cycle) might be large but is not well quantified. Key anthropogenic and natural factors causing a change in radiative forcing from year 1750 to year 2000 are shown in this figure, where wide, colored bars mark the factors whose radiative forcing can be quantified. Only some of the aerosol effects are estimated here and denoted as ranges. Other factors besides atmospheric constituents -- solar irradiance and land-use change -- are also shown. Stratospheric aerosols from large volcanic eruptions have led to important, but short-lived, negative forcings (particularly during the periods 1880-1920 and 1960-1994), which are not important over the time scale since the pre-industrial era and not shown. The sum of quantified factors in the figure is positive, but this does not include the potentially large, negative forcing from aerosol indirect effects.
Views: 832     Downloads: 227     Rating: 4
Back to the future: The science of building scenarios
Main greenhouse gases
Temperature and CO2 concentration in the atmosphere over the past 400 000 years
Temperature trends and projections
Variations of the Earth's surface temperature for the past 100 millions years
Past and future CO2 concentrations
Cooling factors
Kyoto protocol, 2002 target status