Planet temerature warmest in the last 12,000 years
A research team led by NASA's James Hansen has concluded that the Earth's surface temperature has reached its highest point of the current interglacial period which began about 12,000 years ago. Global temperature is now within about 1.8 degrees Fahrenheit--1 degree Celsius--of it's highest point in the last million years.
The earth has been warming at about a third of a degree Fahrenheit--0.2 degrees Celsius--per decade for the last three decases.
A report in the journal Nature found some 1,700 plant, animal and insect species that are moving poleward at an average of about 4 miles per decade in the last half of the 20th century.
In a public statement, Hansen commented that, "This evidence implies that we are getting close to dangerous levels of human-made pollution."
Darkening the near term future is the prediction by scientists at the National Center for Atmospheric Research that the next sunspot cycle will be 30-50% stronger than the last. Both sunspots, which indicate increased solar activity, and global warming gasses are believed to influence Earth's temperature. Since the 1960s, however, temperatures have climbed during peak sunspot activity but, at best, only leveled off during inactive periods.
The sun is now at the bottom of its 11 year sunspot cycle. An especially strong sunspot peak, combined with accelerating accumulations of global warming gases could result in even more rapid temperature increases.
Advocates of sustainability may be strained to find a level of human activity that can truly be sustained. "Sustainable growth" will no longer be possible. The best option may be what Gaia Hypothesis author James Lovelock calls a "sustainable retreat."