Source, info and download: http://iconlibrary.iconshock.com/icons/free-icon-sets-global-warming-advices/ [4]
Links:
[1] http://pulse.veltsos.com/category/it/general
[2] http://pulse.veltsos.com/category/it/world
[3] http://linux.philosweb.com/drupal/files/globalwarmingiconssmall.jpg
[4] http://iconlibrary.iconshock.com/icons/free-icon-sets-global-warming-advices/