Sea levels, Carbon dioxide concentrations, and Global temperatures have moved together over the last 450,000 years.
The graphs show the movement over the last 420,000 years of:
- Carbon dioxide concentrations in the air (the green line),
- Global temperatures (the red line), and
- Sea levels (the blue line).
The carbon dioxide concentrations have fluctuated between about 180 and 280 parts per million (ppm) over this period of 420,000 years, but in the last 50 years, it has rocketed to above 410 ppm. (See the red circle on the green carbon dioxide graph.)
The sea levels and temperatures have moved with carbon dioxide levels in the past. This suggests that the recent increase in carbon dioxide will lead to large rises in sea level and temperature.
The graph shows five periods of high temperatures. We are living in one of those warm periods. During the previous warm period, about 120,000 years ago, the temperature was a few degrees warmer than at present, and the sea level rose about 8 meters higher than the
The work of Hansen and Sato provided the basis of this graph
(John Englander: Oceanographer)