/sci/ - Science & Math

>>9459541
covariance between atmospheric CO2 concentration, surface temperature and sea level

The history of Earth's climate is essentially the history of the carbon cycle being forced by tectonics (on the million-year-timescale) and orbital elements (on the (multi)millennial timescale) and geologic history provides us with a number of imperfect analogues:

The first analogue that we are already beginning the enter is the Eemian (120,000 years ago), when sea level was 6 - 9 meters higher.

The next one are the interglacials of the Mid-Pliocene Warm Period (3 Million years ago), which was the last time the atmosphere had a CO2 concentration of 400ppm. At that time, Greenland, the WAIS and the Aurora subglacial basin were ice-free and sea level was ~22 meters higher.

The next one is the Miocene (~12 Million years ago), when a CO2 concentration of around 500 ppm and a surface temperature of 3 - 4 °C warmer than pre-industrial times lead to a sea level ~40 meters higher than today. Ice was at that time largely restricted to the interior of Antarctica.

The last analogue will be the Eocene (more than 36 million years ago) when CO2 concentration was above 650 ppm, the planet was in the ice-free condition and thermophilic reptiles roamed the Arctic.

The relationship between CO2 and climate is so straight-forward and uncontroversial that it really takes a proper brainwashing not to see it.

Not only is there a good first-order relationship between CO2 concentration and the mean state of the climate (high CO2 world --> "hothouse", ice-free state; low CO2 world --> "icehouse", continental ice sheets), but there's also evidence for the effect of carbon injection into the atmosphere on much shorter timescales. The Eocene hyperthermals are a famous example and there are even more significant events (so called "greenhouse crises") during the Triassic. They coincide with peaks in CO2 concentration and are accompanied by major faunal and floral turnover and extinction in both the marine and terrestrial realms.

The people who treat this subject as some sort of joke are being both incredibly inept as well as fantastically irresponsible.