Climate
The Devonian was a relatively warm period, and probably lacked any glaciers. Reconstruction of tropical sea surface temperature from conodont apatite implies an average value of 30 °C (86 °F) in the Early Devonian. CO2 levels dropped steeply throughout the Devonian period as the burial of the newly-evolved forests drew carbon out of the atmosphere into sediments; this may be reflected by a Mid-Devonian cooling of around 5 °C (9 °F). The Late Devonian warmed to levels equivalent to the Early Devonian; while there is no corresponding increase in CO2 concentrations, continental weathering increases (as predicted by warmer temperatures); further, a range of evidence, such as plant distribution, points to Late Devonian warming. The climate would have affected the dominant organisms in reefs; microbes would have been the main reef-forming organisms in warm periods, with corals and stromatoporoid sponges taking the dominant role in cooler times. The warming at the end of the Devonian may even have contributed to the extinction of the stromatoporoids.
Read more about this topic: Devonian
Famous quotes containing the word climate:
“Is not their climate foggy, raw, and dull,
On whom, as in despite, the sun looks pale,
Killing their fruit with frowns?”
—William Shakespeare (1564–1616)
“The climate has been described as “ten months winter and two months mighty late in the fall.””
—Administration in the State of Colo, U.S. public relief program (1935-1943)
“The climate of Ohio is perfect, considered as the home of an ideal republican people. Climate has much to do with national character.... A climate which permits labor out-of-doors every month in the year and which requires industry to secure comfort—to provide food, shelter, clothing, fuel, etc.—is the very climate which secures the highest civilization.”
—Rutherford Birchard Hayes (1822–1893)