Sun causing global warming? 2 reasons why not
Is the sun causing global warming? Solar physicist C. Alex Young – who leads EarthSky’s daily sun news post – says no. Read the quick-and-easy-to-understand explanation here. Original article via NASA. Edits by EarthSky.
Is the sun causing global warming?
No. The sun can influence Earth’s climate, but it isn’t responsible for the warming trend we’ve seen over recent decades. We know subtle changes in Earth’s orbit around the sun are responsible for the comings and goings of the ice ages. But the warming we’ve seen in recent decades is too rapid to be linked to changes in Earth’s orbit and too large to be caused by solar activity. Here are two smoking guns that tell us the sun isn’t causing global warming.
1. Since 1978, using sensors on satellites, scientists have been tracking the amount of solar energy that hits the top of Earth’s atmosphere. This measurement tells us that there has been no upward trend in the amount of solar energy reaching our planet.
2. If the sun were responsible for global warming, we’d expect to see warming throughout all layers of the atmosphere, from the surface to the upper atmosphere (stratosphere). But we don’t see that. What we see instead is warming at the surface and cooling in the stratosphere. This is consistent with the warming being caused by a buildup of heat-trapping gases near Earth’s surface, and not by the sun getting “hotter.”
Bottom line: Is the sun causing global warming? A solar physicist with NASA says no. Read the quick-and-easy-to-understand explanation here.