kengr

I used to work with trendline analysis for a living, so I have a better handle on overlapping trends than most folks.

When talking about natural climate trends, the short term is that we're (slowly) coming out of a record low sunspot cycle. The lower solar output cooled the globe by one or two kelvins (ie degrees centigrade for those who don't already know).

The medium trend is that we're in the rising part of the 750 year climate cycle. (Which is probably the average of several natural cycles.) The trough was right around 1800. Remember all those stories and artwork showing how bad the Winters were during the American Revolution? This, plus a major volcanic eruption, probably also triggered the French Revolution. The effect is slow and irregular enough that there's considerable argument about when the last minimum and the preceding maximum were, but the consensus is that we're now in the rise.

The long term is that the climate should turn seriously cooler in another two or three thousand years, starting perhaps as soon as a thousand years from now.

In the *really* long term trend, the Sun will bloat into a red giant and swallow the Earth. :-)