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An illustration of ice age Earth at its glacial maximum. A "greenhouse Earth" is a period during which no continental glaciers exist anywhere on the planet. [6] Additionally, the levels of carbon dioxide and other greenhouse gases (such as water vapor and methane) are high, and sea surface temperatures (SSTs) range from 28 °C (82.4 °F) in the tropics to 0 °C (32 °F) in the polar regions. [7]
During this time, the atmospheric carbon dioxide concentration has varied between 180 and 210 ppm during ice ages, increasing to 280–300 ppm during warmer interglacials. [ 114 ] [ 115 ] CO 2 mole fractions in the atmosphere have gone up by around 35 percent since the 1900s, rising from 280 parts per million by volume to 387 parts per million ...
Approximate extent of the Karoo Glaciation (in blue), over the Gondwana supercontinent during the Carboniferous and Permian periods. The late Paleozoic icehouse, also known as the Late Paleozoic Ice Age (LPIA) and formerly known as the Karoo ice age, was an ice age that began in the Late Devonian and ended in the Late Permian, [1] occurring from 360 to 255 million years ago (Mya), [2] [3] and ...
The gradual intensification of this ice age over the last 3 million years has been associated with declining concentrations of the greenhouse gas carbon dioxide, though it remains unclear if this change is sufficiently large to have caused the changes in temperatures.
It was the second-to-latest interglacial period of the current Ice Age, the most recent being the Holocene which extends to the present day (having followed the last glacial period). During the Last Interglacial, the proportion of CO 2 in the atmosphere was about 280 parts per million. [3]
Carbon dioxide concentration during the Middle Pliocene has been estimated at around 400 ppmv from 13 C/ 12 C ratio in organic marine matter [23] and stomatal density of fossilised leaves, [24] although lower estimates of between 330 and 394 ppm over the course of the whole mPWP and 391 ppm in the KM5c interglacial, during the warmest phase of ...
Ice core data for the past 800,000 years (x-axis values represent "age before 1950", so today's date is on the left side of the graph and older time on the right). Blue curve is temperature, [36] red curve is atmospheric CO 2 concentrations, [37] and brown curve is dust fluxes. [38] [39] Note length of glacial-interglacial cycles averages ...
Over the past 800,000 years, [36] ice core data shows that carbon dioxide has varied from values as low as 180 ppm to the pre-industrial level of 270 ppm. [37] Paleoclimatologists consider variations in carbon dioxide concentration to be a fundamental factor influencing climate variations over this time scale. [38] [39]