Debunking this skeptic myth is left as an exercise to the reader
Posted on 17 December 2010 by John Cook
I recently received an email proposing an alternative cause for global warming:
"The real reason for global warming is the earth's orbit around the sun is slowly decaying, and the earth is being pulled closer to the sun."
It's fairly straightforward to determine whether this is actually occuring using direct measurements. Without wanting to give away too many details (for reasons that will soon become apparent), I cited some empirical observations that falsified the "decaying orbit" hypothesis. His response:
"This is where we must agree to disagree. I measure the progression of earth's decaying orbit by the surface temperature, and by the increase of the surface area the sun is warming. Houston is near the equator. Our winters are becoming sunny, and warmer."
I queried why he relies on these indirect methods and ignored the direct measurements I cited. The response:
"I ignore direct readings, because I feel it flawed."
I was never able to extract from him why he felt the direct measurements were flawed, other than a general "I'd rather depend on my own senses" sentiment. But I've intentionally left out the details of my response as I thought I'd leave it as an exercise to the reader as to how you would respond to the argument that global warming is being caused by a decaying orbit. I'd be interested to see what different approaches others take.