| Ice Age Climate
- 18,000 Years Ago Greenhouse Gas Concentrations were lower than present by 50% and vast ice sheets and sea ice covered northern latitudes |
 |
| Cretaceous-Tertiary Climate
- 66 Million Years
Ago, Greenhouse
Gas Concentrations were higher than present by about a factor of 3 |
 |
| Permian Climate
- 255 Million Years
Ago Vast deserts covered the continents, 90% of all life perished but reptiles expanded |
 |
| Ice House
Climate - 650
Million
Years
Ago The sun was about 7% fainter than today and the land mass near the South Pole was covered by a vast ice sheet |
 |
