Re: The open question is if ...
" they could, I suppose, make some sort of prediction that we could use as a guideline."
in 2040, you'll see cold temperatures similar to 1970's and 1900's, just like the mid-2000's were similar to the mid 1930's. ~70 year cycle. Prediction should be accurate. You're welcome.
Fixed It For Ya.
There are also long cycles in the northern hemisphere of about 500 years. 2000'-ish was at the peak of one of those, oh by the way. The last "warm period" was 1500'ish. The mid 1700's [think valley forge and frozen-over Thames] was the last major cold period. In the ~1000's (or so) there was a warm peak. That's about the time that Eric the Red gave "Greenland" its name because it was, well, GREEN. Unfortunately 100 or so years later, NOT so green, and Viking settlements did rather poorly as a result. Yeah, he found Greenland just after a warming peak, while it was on its way over the hump.
So let us learn from actual history and pay attention to these normal temperature cycles, and base our predictions on THOSE, instead of bogus computer models that were rigged for an outcome by AlGore's religious zealots [who are probably just corrupt political elitists trying to manipulate people].