This is a response to G. Horner’s misleading comment. I’ve decided to post it here rather than bury it in the responses:

According to GISTEMP LOTI, the difference between the global average temperature in 2016 and 2015 was 0.34 degrees Celsius or .612 F.

That is well outside the margin of error.

Which brings up a point: Note that I went from a number with two decimal places to one with 3 — from hundredth of a degree to thousandths — by multiplying.

Similarly, the average global temperature for a given year is not one measurement, but an average of several thousands. It is by averaging — IOW, dividing — that you get a result accurate to within hundredths of a degree.

While you are correct that the difference between 2015 and 2014 is quite small, it was, in fact .144 F, per GISSTEMP.

Your claim re increases per five year period: The difference between 2005 and 2000 was .46 C = .828 F. So that claim is wrong, too.

And, if you drill down to how the “hottest year” is determined, you’ll find that, given a range of possible years, the year with the highest probability of being the hottest year gets the title. I haven’t looked at this year’s numbers, but the last time I did (2014, IIRC) there was a probability of .48 that that current year was the warmest on record. That probability was higher than the probability for other years, so…

So, what’s going on here? You are an anonymous person making claims based on fictitious numbers. I don’t know if you made up the numbers yourself or if you’re trolling on behalf of someone else.

But unlike you, I actually have been following climate science for 28 years. I’m an economist with the background to understand the science at a skilled layman level, and I have the data on my computers. So does Joe Romm.