re: #122 Pythagoras

On this, we agree precisely. My goal is not to show that the recent warming isn’t anthropogenic; obviously some of it is.

The reason AGW is “urgent” is that we’re about to hit a “tipping point” where the temperature is going to do more than rise a little bit. The current global temperature is not, yet, viewed as worse than it was 100 years ago. But if it rises suddenly and uncontrollably so that the polar ice caps melt and sea level rises a lot, then the warming becomes a problem.

But if it was warmer a thousand years ago and it didn’t tip then, we don’t yet have a problem. Global warming could need bold action eventually, but the statements that we only have a few years to fix the problem depend on it being warmer now than in the middle ages.

Not so fast there. If it was warmer a thousand years ago and it didn’t tip then, we may still have a problem. THIS time, along with whatever temperature we reach, we have a forcing mechanism that wasn’t in force last time to the same extent, and it keeps pushing. Today’s temperatures cannot as easily drift back the other way.

As to having “only a few years”, all this is incremental. We’ve already hit some tipping points. Various amphibian species are going extinct, for example. At any given date in the future, there will be an opportunity to change the course of the rest of the future. But the longer we wait, the more of the bullet we’re going to have to bite.

To strike an analogy, suppose you’ve been diagnosed with cancer. It doesn’t spread like wildfire, not overnight. You can put off the operation for a week, or two weeks, or a month. Or longer. But each delay cuts into your chances.

The analogy is a bit strained, because this climate thing won’t kill us. Not as a species. We can screw the pooch completely, ignore it until it’s too late to avoid a tropical climate at Anchorage, and lose billions of people, and come out at the other end with a rebuilt civilization and a bright future. Not everything rides on getting this right.