How did the cavemen end the last ice age? pollution? litter? did they invent the suv?

[tatimsaspas]

Or it is maybe that ice ages come and go regardless of human activities?

[LissReynolds]

I'd say they had industrial coal power plants. (sarcasm)

Global warming and cooling is cyclical and natural.

I think no one on this site gets sarcasm. I took this question as sarcasm. No senses of humor around here, me thinks.

[Benjamin]

Um mmm, cavemen didn't end the last ice age. The comings and goings of ice ages are now thought to be related to Milankovich cycles,[1] or small predictable changes in Earth's orbit around the sun.

Just because something had a "natural' cause in the past, doesn't mean that it always must have a natural cause. Take forest fires for example. They have long been caused by lightening strikes ("natural"), but this doesn't mean that a careless camper or arsonist can't also start a forest fire.

[Tellem]

I just love all of the fallacious correlation that goes on here!

If you had looked at any of the statistics or understood any of the science, you would see the drastic differences between the end of the last ice age and our current situation.

Go take a probability & reasoning course, followed by a science class, then get back to us.

[DidierDrogba]

"Thought to be" - - - - -

Bottom line, scientists can't tell you precisely what changes in what forcings caused the last Ice Age to begin and end, or what caused the intermittent warm and cool periods since the last Ice Age ended.

Does that mean that the 20th century warming COULDN'T have been caused by humans?

NO, IT DOES NOT. PAST NATURAL WARMING, EVEN PAST NATURAL WARMINGTHAT IS NOT FULLY UNDERSTOOD, DOES NOT PRECLUDE MAN-MADE WARMING TODAY.

But it DOES preclude the INFERENCE that today's warming is man-made, absent direct proof.

And that inference is the case for man-made global warming.

[Foobs]

It would be easier to take global warming skeptics seriously if they didn't have so many morons in their camp.

Lets begin with a simple equation: Energy In = Energy Out.

So the energy from the sun that enters the planet must leave. Clearly, this isn't strictly true. In the short term, temperatures change drastically (as in day and night). In the long run, they still change, but the energy involved will be a small fraction of the heat that comes to the earth. As such, we've made a reasonable simplification.

Now, we'll add transport:

Energy out = Earth Temperature / Resistance to Heat Loss = T / R

So, Energy In (E) = T / R therefore T = E * R

So, the Earth's steady state temperature is a function of the energy that reaches it and it's resistance to heat loss. Anything that effects either parameter will affect temperature. The energy that reaches the Earth is most strongly affected by things outside of human control (solar activity, the tilt of the Earth's axis, etc), though not entirely. The Earth's resistance to heat loss has a number of natural components, but also a number that are affected by human activity. The meaningful question is whether the human effects are a significant part of the whole. If they are, then there are serious problems requiring serious solutions. Of not, then there is nothing to worry about.

I assume that you recently stopped posting things like "It's cold today, so global warming is obviously nonsense!". Now you've graduated to nonsense like this question. Keep up the progress and in a few years you might be capable of an intelligent conversation. Good luck.