Why? During the Great Ice Age, remants of which are still with us, even though the planet overall has been warming over the last 10,000 years, why would there have been less Carbon Dioxide in the air?My way of thinking, there should have been more. More than we currently have in the Atmosphere. ( If I researched it properly, from Google Sites, The Great Ice Age, ), ( less CO2 ), . Same reference stated 2/3, two thirds, of the Planet Earth for 70 thousand years covered in ice. OK. No trees in Northern Hemisphere, to speak of that is, so no soaking up of CO2. No grasslands to speak of, so no soaking up of CO2. Where did the CO2 spend The Great Ice Age? westwind.