2009-11-30 Scientific American
Evidence for human interference with Earth’s climate continues to accumulate
Answers to the most common mythological claims by contrarians and denialists (follow the link for the answers):
Claim 1: Anthropogenic CO2 can’t be changing climate, because CO2 is only a trace gas in the atmosphere and the amount produced by humans is dwarfed by the amount from volcanoes and other natural sources. Water vapor is by far the most important greenhouse gas, so changes in CO2 are irrelevant.
Claim 2: The alleged “hockey stick” graph of temperatures over the past 1,600 years has been disproved. It doesn’t even acknowledge the existence of a “medieval warm period” around 1000 A.D. that was hotter than today is. Therefore, global warming is a myth.
Claim 3: Global warming stopped a decade ago; Earth has been cooling since then.
Claim 4: The sun or cosmic rays are much more likely to be the real causes of global warming. After all, Mars is warming up, too.
Claim 5: Climatologists conspire to hide the truth about global warming by locking away their data. Their so-called “consensus” on global warming is scientifically irrelevant because science isn’t settled by popularity.
Claim 6: Climatologists have a vested interest in raising the alarm because it brings them money and prestige.
Claim 7: Technological fixes, such as inventing energy sources that don’t produce CO2 or geoengineering the climate, would be more affordable, prudent ways to address climate change than reducing our carbon footprint.