Why do I accept the reality of human-caused global warming? Because I accept the following top-ten list of physics facts, which have never been disputed in the scientific literature. This is also why the American Physical Society of 47,000 physicists says "The evidence is incontrovertible: Global warming is occurring".
PHYSICS FACT #1: The atmospheric carbon dioxide concentration has increased rapidly since the beginning of the industrial revolution, after being nearly constant for thousands of years.
PHYSICS FACT #2: The surplus carbon dioxide has an isotope composition that can only come from fossil fuels. The increase in concentration is not natural; it comes from human activities.
PHYSICS FACT #3: The radiative properties of carbon dioxide have been measured by physicists in the laboratory: It absorbs thermal infrared (heat) radiation.
PHYSICS FACT #4: Because carbon dioxide has this heat-absorbing physical property, the increase in its concentration has increased the infrared opacity of the Earth's atmosphere and blocks the outward radiation of heat.
PHYSICS FACT #5: More net energy is now coming into the Earth's atmosphere from sunlight than is going back out to space as heat radiation.
PHYSICS FACT #6: Conservation of energy is a fundamental law of physics. When more energy comes in than goes out of a system, it warms up.
PHYSICS FACT #7: The Earth's temperature is increasing by an amount that is consistent with predictions, based on the laws of physics and the well known heat-absorbing properties of the excess carbon dioxide
PHYSICS FACT #8: Measurements show that night-time temperatures are increasing faster than daytime temperatures, just as physicists predicted. The excess carbon dioxide causes a warmer night-time sky which is the main source of heat at night, but does not affect the brightness of the sun, which is the main source of daytime heat.
PHYSICS FACT #9: Measurements show that the top of the atmosphere is getting colder, just as physicists predicted, because the excess carbon dioxide in the lower atmosphere is blocking the heat from below.
PHYSICS FACT #10: Heat-sensing instruments on satellites have measured a reduction in the amount of infrared radiation coming from the atmosphere, at the exact wavelengths predicted by physicists.
Anybody who calls themselves a "skeptic" must refute one or more of these physics facts by publishing the extraordinary evidence for their claim. Otherwise, it the word "denier" is appropriate.
Thanks for this list goes to Mark Boslough
I first came across the list on the great blog WaterWired