Indeed, the natural long - term climate trend today would be toward a cooler climate were it not for human activities. (ramblingsdc.net)
The moral of the story - don't use short term weather patterns to draw conclusions about long term climate trends. (skepticalscience.com)
It is essentially irrelevant whether the insolation has changed at that level, both when trying to understand the regional south pole climate changes, and long term climate trends on Mars. (realclimate.org)