Comment Causal link established: UV Radiation that warms (Score 1) 628
Don't be too sanguine that the "global cooling" folks are all nutters.
A 2001 NASA/GISS study by Drew Shindell found a causal link between the Little Ice Age and the Maunder Minimum (a prolonged period of no sunspot activity first observed by Galileo). The causal link was the loss of facular ultraviolet radiation from sunspots. The effect was a general -0.3 to -0.4 degrees Celsius cooling of the Earth, but since windborne oceanic moisture slowed down, inland winters became more severe.
We've already seen a -0.1 degrC (-0.33 w/m-2) effect from a decrease in solar radiance since the early 1990's. Some astrophysicists are already predicting an additional -0.1 to -0.2 degrC decrease in solar energy by 2025.
Although that's almost as much as the temperature decrease modeled to cause the Little Ice Age, remember the planet has warmed since then, so the effect will be to blunt global warming first, not send us back into another Little Ice Age.
A 2001 NASA/GISS study by Drew Shindell found a causal link between the Little Ice Age and the Maunder Minimum (a prolonged period of no sunspot activity first observed by Galileo). The causal link was the loss of facular ultraviolet radiation from sunspots. The effect was a general -0.3 to -0.4 degrees Celsius cooling of the Earth, but since windborne oceanic moisture slowed down, inland winters became more severe.
We've already seen a -0.1 degrC (-0.33 w/m-2) effect from a decrease in solar radiance since the early 1990's. Some astrophysicists are already predicting an additional -0.1 to -0.2 degrC decrease in solar energy by 2025.
Although that's almost as much as the temperature decrease modeled to cause the Little Ice Age, remember the planet has warmed since then, so the effect will be to blunt global warming first, not send us back into another Little Ice Age.
