re: #522 LudwigVanQuixote

As a scientist, it’s been my experience that valid scientific arguments usually don’t have the political consequences I mentioned. I note that you did not refute my points, just whine about Exxon. They produce a panoply of incredibly useful products, at reasonable cost, but that makes them EVIL, right?

But okay, now let’s make the scientific argument. Fact A: The climate of the earth has been both much warmer and much colder than it is now, including episodes of both within recorded human history. Fact B: None of the events mentioned in Fact A could possibly have been caused by human activity. Fact C: it is not necessary to invoke human activity to explain anything that is currently being observed. Fact D: Even if you ignore Fact C, CO2 is not well correlated with 20th century climate. The climate was cooling for more than two decades in the middle of the century, at a time when fossil fuel production and consumption was expanding markedly. Over the past 9 or ten years, the climate has not changed significantly- if anything there is a slight cooling trend. Yet CO2 continued to rise. The greenhouse effect of CO2 is trivial compared to the effect of water vapor, a far more prevalent atmospheric gas.

So what exactly is the actual physical data showing that CO2 drives climate change? Hint: the output from computer models does not constitute data. Physical observations constitute data.