"How do people come to the conclusion that another side is needed?"

Check out the pseudo-science from supposed Nobel Prize winner Steve Running here.

Excerpt:

The lingering argument which disputes planetary warming as a man-made phenomenon centers on “natural variability,” maintaining current temperature changes are part of natural fluctuations in the earth’s climate.

But that line of thought doesn’t hold, Running said. If that was the case, there would be more deviation in temperatures. Some areas would cool while others heated up. Scientists can’t find evidence that things are cooling down, anywhere, he added.

“Then that isn’t natural variability.”