Earth's Energy Budget Remained Out of Balance Despite Unusually LowSolar Activity

Earth's Energy Budget Remained Out of Balance Despite Unusually Low
Solar Activity
http://www.nasa.gov/topics/earth/fea...gy-budget.html

A prolonged solar minimum left the sun's surface nearly free of
sunspots and accompanying bright areas called faculae between 2005 and
2010. Total solar irradiance declined slightly as a result, but the
Earth continued to absorb more energy than it emit throughout the minimum.

Hansen's team concluded that Earth has absorbed more than half a watt
more solar energy per square meter than it let off throughout the six
year study period. The calculated value of the imbalance (0.58 watts of
excess energy per square meter) is more than twice as much as the
reduction in the amount of solar energy supplied to the planet between
maximum and minimum solar activity (0.25 watts per square meter).

"The fact that we still see a positive imbalance despite the
prolonged solar minimum isn't a surprise given what we've learned about
the climate system, but it's worth noting because this provides
unequivocal evidence that the sun is not the dominant driver of global
warming," Hansen said.

According to calculations conducted by Hansen and his colleagues, the
0.58 watts per square meter imbalance implies that carbon dioxide levels
need to be reduced to about 350 parts per million to restore the energy
budget to equilibrium. The most recent measurements show that carbon
dioxide levels are currently 392 parts per million and scientists expect
that concentration to continue to rise in the future.

See: http://www.nasa.gov/topics/earth/fea...gy-budget.html