Global mean sea level has been rising at an average rate of 1 to 2 mm/year over the past 100 years, which is significantly larger than the rate averaged over the last thousand years. Projected increase for the 21st century is about 0.5 meter, but estimates range widely. Some changes, particularly part of the pre-1960 temperature record, show some relationship with solar output, but the more recent warm era is not well correlated. The exact magnitude of purely natural global mean temperature variance is not known precisely, but model experiments excluding solar variation indicate that it is likely less than the variability observed during this century
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