(30) NOAA.http://en.wikipedia.org/wiki/Image:Enso_elnino.png. Public License.
(31) NOAA.http://en.wikipedia.org/wiki/Image:Picea_glauca_taiga.jpg. Public
Domain.
(32) http://commons.wikimedia.org/wiki/File:
LongleafPineForestBurnComparaison.jpg. GNU-FDL.
(33) NASA, CK-12 Foundation. Sunspots on the face of the Sun.. Public Domain.
(34) http://en.wikipedia.org/wiki/Image:AtmosphCirc2.png. CC-BY-SA 1.0.
(35) Cesar Paes Barreto. The Amazon river and rainforest in Brazil.. The photographer of
this work allows anyone to use it for any purpose including unrestricted
redistribution, commercial use, and modification..
(36) http://commons.wikimedia.org/wiki/File:Subtropworldmap.PNG. Public
Domain.
(37) http://en.wikipedia.org/wiki/Image:Instrumental_Temperature_Record.png.
GNU-FDL.
(38) http://en.wikipedia.org/wiki/File:Pseudotsuga_menziesii_28236.JPG.
GNU-FDL.
(39) USGS.http://en.wikipedia.org/wiki/Image:Pleistocene_north_ice_map.jpg.
Public Domain.
(40) The location of the subpolar climate.. GNU-FDL.