400

Crossing the Rubicon pales in comparison to reaching the threshold of 400 parts per million of CO2, the greenhouse gas that will change a benign earth into something altogether different thanks to the continued and unfettered use of fossil fuels all over the world.

The level of the most important heat-trapping gas in the atmosphere, carbon dioxide, has passed a long-feared milestone, scientists reported Friday, reaching a concentration not seen on the earth for millions of years.

Indirect measurements suggest that the last time the carbon dioxide level was this high was at least three million years ago, during an epoch called the Pliocene. Geological research shows that the climate then was far warmer than today, the world’s ice caps were smaller, and the sea level might have been as much as 60 or 80 feet higher.

With "luck", combined with continued use of fossil fuels, we might reach the Eocene era, a hot house scenario that could end man's existence on planet earth.

The Eocene Epoch contained a wide variety of different climate conditions that includes the warmest climate in the Cenozoic Era and ends in an icehouse climate. The evolution of the Eocene climate began with warming after the end of the Palaeocene-Eocene Thermal Maximum (PETM) at 56 million years ago to a maximum during the Eocene Optimum at around 49 million years ago. During this period of time, little to no ice was present on Earth with a smaller difference in temperature from the equator to the poles. Following the maximum, was a descent into an icehouse climate from the Eocene Optimum to the Eocene-Oligocene transition at 34 million years ago. During this decrease ice began to reappear at the poles, and the Eocene-Oligocene transition is the period of time where the Antarctic ice sheet began to rapidly expand.

With no ice, sea level rise will be nearly 300 feet and...

Using isotope proxies to determine ocean temperatures indicate sea surface temperatures in the tropics as high as 35 °C (95 °F) and bottom water temperatures that are 10 °C (18 °F) higher than present day values.[15] With these bottom water temperatures, temperatures in areas where deep-water forms near the poles are unable to be much cooler than the bottom water temperatures.

What makes matters worse is man's ever expanding population and pollution footprint as the Eocene, even though extremely hot, was pristine and teemed with life because we were not there, littering the planet with innumerable pollutants while plundering the place with unbridled greed and ferocity.

Continue the status quo is no longer viable. To continue to burn fossil fuels at the expense of developing alternative ways of generating energy is suicide but we already know about this as the President contemplates approving Keystone, the truly modern way to bring forth a new Eocene within our lifetimes instead of having to wait for it to happen within a few centuries.