Forces more powerful than your iPhone charger: How much energy would it take to warm the universe by 4,000 degrees C.?

Astronomers find evidence of 'cosmic climate change'

ScienceDaily (Nov. 2, 2010) — A team of astronomers has found evidence that the universe may have gone through a warming trend early in its history.
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'Of course, the temperatures we measured are a bit different from what you find on Earth," commented Becker. "One billion years after the Big Bang, the gas we measured was a 'cool' 8,000 degrees Celsius. By three and a half billion years the temperature had climbed to at least 12,000 degrees Celsius."