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Palaeozoic tropical rainforests and their effect on global climates: is the past the key to the present?
Author(s) -
CLEAL CHRISTOPHER J.,
THOMAS BARRY A.
Publication year - 2005
Publication title -
geobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.859
H-Index - 72
eISSN - 1472-4669
pISSN - 1472-4677
DOI - 10.1111/j.1472-4669.2005.00043.x
Subject(s) - permian , sink (geography) , rainforest , paleozoic , carbon sink , global cooling , geology , global warming , wetland , carboniferous , physical geography , earth science , environmental science , paleontology , climate change , oceanography , ecology , geography , cartography , structural basin , biology
Wetland forests, known as coal forests, extended over large areas of the palaeotropics during the Late Carboniferous and the Permian Periods. They were initiated during the Serpukhovian Age as a response to lowering sea levels having exposed large areas of continental shelf. They expanded dramatically during the late Bashkirian Age, but then contracted by over one‐half during the Kasimovian Age. The estimated loss of carbon sink probably resulted in an annual increase in atmospheric CO 2 of about 2–5 ppm, and coincided with clear evidence of global warming in both the northern and southern high latitudes. A return to cooler conditions in very Early Permian times coincided with an expansion of the palaeotropical coal forests in the Far East, but this was short‐lived and most of the rest of the Permian was a time of global warming. The Palaeozoic evidence clearly confirms that there is a correlation between levels of atmospheric CO 2 and global climates. However, care must be taken in extrapolating this evidence to the present‐day tropical forests, which do not act as a comparable unsaturated carbon sink.