Your world population prediction is horrible. You are getting it from an opinion piece in the new york times. At least use the UN's numbers: http://en.wikipedia.org/wiki/World_population

Their highest estimate is 14 billion by 2100, and their lowest is 5.5 billion.

Friedman is far from the only one to assume that we will reach high levels of industrialization. Most of the predictions for our CO2 output in the future assume that Africa will be industrialized and pumping a lot more of it into the atmosphere. Everyone makes the prediction of a richer world, with a doubling in population at the most. Not some ridiculous factor of 10 increase.

We're not talking about slightly warmer weather here. If we're serious about listening to climate scientists, then listen. It's not about a few degrees (warmer weather generally helps plants, after all). It's about changes in rainfall causing droughts and floods. Hard to simply "change crops" if all your soil has blown away.

Yes we are, go look up the IPCC's climate reports. Their median prediction is about a 2 degrees Celsius increase.

That's not how people work, and you know it. We were warned about New Orleans literally years ahead of time. It would have cost a billion dollars, in the most prosperous nation on earth, to raise the levees. Pocket change compared to the damage.

So you want the same idiots in charge of raising a levee to deal with global warming?! Look, people in government face relatively similar incentives at different levels, why would you expect people to be behave differently if they face the same incentives? If you really don't want people building in areas that are in danger of flooding then get rid of federal flood insurance.

Did we? Of course not. Why do we think Calcutta will be any different? They'll delay and delay until their houses are swept away by record-level storm surges.

I don't know anything about Calcutta, I'm guessing they probably don't have an idiotic federal flood insurance program that allows people to get away with living in these dangerous areas.

So we have reason to believe that humanity will not go extinct. How encouraging.

No we have a reason to doubt that there is some kind of "perfect temperature" that we must remain at.

This is pretty meaningless, because over the past few thousands of years we haven't had 7-billion mouths to feed. Most places on Earth are habitable if your population density is low enough.

There has never been mass starvation in a democracy. Given the right incentives farmers can find a way to feed people. They have been doing it quite successfully for ten thousand years. We also have a relatively untapped research areas of genetic crop modification which could drastically increase our ability to feed people. It was a change in the stalks of rice plants that allowed us to avoid mass starvation in India and China during the 70's and 80's.

All-in-all, a bunch of hand-wavey, poorly thought out attempts to dismiss the damage of climate change and ecosystem disruption. Color me unimpressed with this "economist."

After your use of the idiotic 72 billion people prediction I'm not inclined to listen to any of your opinions.

Well that explains it. Libertarians' eyes tend to glaze over when the world gets subtle.

No, we just realize that the doom and gloom preachers have been around throughout human history, and they are generally as wrong now as they were when they predicted god's wrath.