In his latest reply to co-blogger Bryan Caplan, Yoram Bauman writes:

If more economists like Bryan were upfront about their agreements with basic climate science then I would feel better about not having time to respond to people like David Henderson, who goes to great linguistic lengths in an effort to argue that global temperatures have not been increasing over the past century.

Bauman links, correctly, to my response to his question. But in case you didn’t follow that link, here’s my statement of his question [it’s word for word what he asked] and my response:

Yoram: That global temperatures have been increasing over the past century?
David: No. “Have been” implies not only that they have increased but also have increased in the recent past. Global temperatures have increased over the past century. Of that fact, I can find no dispute, no matter which side of the issue climate scientists are on. But global temperatures have not increased for over a decade.

Bauman calls this “great linguistic lengths.” I call it proper use of verb tenses. I bet you he does understand the difference.

In case some of the readers don’t, though, let’s get it away from global warming and look at a more neutral topic. Imagine that you are 70 years old and that when you were 10, someone told you that you should go to the dentist every year for a checkup. Imagine that you faithfully went every year for 50 years but haven’t gone for the last 10 years. Someone asks you whether you have been going to the dentist for the last 60 years. What is the right answer?