Charles Pierce does his usual exemplary job of hauling Marco Rubio out to the woodshed, and I can’t improve on it. I do want to mention though, that he missed one point that is a common mantra of the climate change denialists.
RUBIO: "What I said was that humans are not responsible for climate change in the way that some of these people out there are trying to make us believe for the following reason: I believe the climate is changing because there has never been a moment when the climate is not changing..The question is what percentage of that — or what is due to human activity?…If we do the things they want us to do — cap and trade, you name it — how much will that change the pace of climate change versus how much will it cost our economy? Scientists can’t tell us what impact it would have on reversing these changes. But I can tell you with certainty that it would have a devastating impact on our economy."
That’s such a bad question, it’s not even wrong. We don’t care what percentage of the change is due to human activity.
Here’s a metaphor to explain that: picture a balance. On one pan is a mass representing carbon being pumped into the atmosphere; on the other, a mass representing the carbon being extracted. Both of these processes are going on all the time, and have been for billions of years: a plant breathes in, extracting carbon and fixing it as carbohydrates, the plant dies and that carbon is released by decay or burning. The two sides of the balance are roughly equal, with variations over time, but they’re mostly stably in equilibrium.
Just to make it concrete, imagine that we’ve got 10 kilogram weights in each pan.
Now we add human activity: someone adds one gram to one side of the balance. It’s a difference of only 0.01%. But the arm of the balance will inexorably tilt toward the heavy side. We care about the total amount of human-contributed carbon load, because that’s what we have to remove or compensate for in order to restore the balance…but the concern right now is the slide downward on one side, that is getting greater and greater even if we stopped throwing more mass at the problem.
We’ve thrown all this carbon that had previously been sequestered — it used to be on the side representing extracted carbon, and human activity has moved it to the other side. We have an imbalance, and it needs to be corrected, and while the Rubios of the world are fussing over exactly how severe the difference is, the problem is increasing.