A few individuals and groups have queried Skeptical Science about a misleading and myth-filled climate page from PreventDisease.com. The page is actually a re-post of a document put together by amateur astronomer Gregg D. Thompson. We at Skeptical Science aim to please, so here we will examine the claims made in this document. Since it consists almost entirely of long-debunked myths, most of our response will consist of linking to existing rebuttals in the Skeptical Science database. Unfortunately, but unsurprisingly, the document contains no supporting evidence or references, so we will evaluate its arguments on their own merit (and lack thereof).

Human Emissions are Small

The document begins by making a number of irrelevant and misleading statements about human carbon dioxide (CO2) emissions. The three principle errors are:

"CO2 is less than a mere four 100ths of 1% [of the atmosphere]"

"Humans produce only 3% [of global CO2 emissions]"

"If the public were aware that man-made CO2 is so incredibly small there would be very little belief in a climate disaster"

These statements presume that anything that is present as a small proportion can have no effect, which is clearly nonsense. In reality, the percentages of CO2 in the atmosphere and of human CO2 emissions are irrelevant to the risk that those emissons pose. A very small proportion of arsenic in drinking water can be very dangerous, for example. 99% of the atmosphere is composed of non-greenhouse gases, so the entire greenhouse effect is caused by the remaining 1%

The second statement ignores the fact that although natural emissions are much larger than human emissions, the natural carbon cycle is in balance. Natural carbon sinks absorb more than natural carbon sources emit, and human emissions upset that balance. That's why humans are responsible for the 40% increase in atmospheric CO2 over the past 150 years.