The mid-Cretaceous super plume, carbon dioxide, and global warming.
Carbon-dioxide releases associated with a mid-Cretaceous super plume and the emplacement of the Ontong-Java Plateau have been suggested as a principal cause of the mid-Cretaceous global warming.  We developed a carbonate-silicate cycle model to quantify the possible climatic effects of these CO2 releases, utilizing four different formulations for the rate of silicate-rock weathering as a function of atmospheric CO2.  We find that CO2 emissions resulting from super-plume tectonics could have produced atmospheric CO2 levels from 3.7 to 14.7 times the modern pre-industrial value of 285 ppm.  Based on the temperature sensitivity to CO2 increases used in the weathering-rate formulations, this would cause a global warming of from 2.8 to 7.7 degrees C over today's global mean temperature.  Altered continental positions and higher sea level may have been contributed about 4.8 degrees C to mid-Cretaceous warming.  Thus, the combined effects of paleogeographic changes and super-plume related CO2 emissions could be in the range of 7.6 to 12.5 degrees C, within the 6 to 14 degrees C range previously estimated for mid-Cretaceous warming.  CO2 releases from oceanic plateaus alone are unlikely to have been directly responsible for more than 20% of the mid-Cretaceous increase in atmospheric CO2.
Caldeira
K
K
Department of Applied Science, New York University, USA.
Rampino
M R
MR
D001272:Atmosphere; D002245:Carbon Dioxide; D002254:Carbonates / Q000032:analysis; D002980:Climate; D018534:Earth, Planet; D019419:Evolution, Planetary; D055593:Geological Phenomena; D005844:Geology; D017752:Greenhouse Effect; D008956:Models, Chemical; D009792:Oceans and Seas; D017640:Silicates / Q000032:analysis
D002254:Carbonates; D017640:Silicates; D002245:Carbon Dioxide