Richard Muller is a smart guy and he’s a climate skeptic. Or at least, he was. He’s a professor of physics at the University of California Berkeley. He’s written a book called Physics for Future Presidents. And, as a scientist, he was skeptical about the quality of the data that gets used to calculate global temperature.

There are a lot of problems with collecting temperature data from all around the world, measured in many different ways, and turning it into one big number. Dr. Muller chronicles many of them himself in his recent Wall Street Journal article. Some of the stations are in cities, where buildings and roads trap heat (known as the urban heat island effect) and are hotter than outside the city. Other stations used to be outside the city, but the city has grown up around the weather station over the years.

But here’s the great thing that Dr. Muller did: Instead of just complaining about how bad the temperature record was, he decided to give it a go himself. And he did just that. He pulled together a team of scientists and statisticians called BEST, Berkeley Earth Surface Temperature, who took all the data and started from scratch to see what they came up with and whether the planet is heating up or not.

The BEST team did a few things differently. They used a lot more weather stations (over 39,000) than previous data sets that only used the temperatures stations that had been running for a long time, about 7000 of them. They used new statistical approaches to account for stations that are “good” and stations that are “bad.” (Note: Previous temperature records from NOAA, NASA and the UK Met Office also take into account weather station quality. Read more about the BEST team’s methods here.) BEST also made sure all their data, as well as their number-crunching techniques were all publicly available for others to use and comment on what they did. Very cool. Teachers – you can even use some of this data for graphing and statistics exercises in your classroom. Watch out, though – there are over 1.6 billion measurements there.

The BEST team has now submitted 4 papers to be published, but they’ve also released preliminary reports on their findings, which have been getting a lot of press. Here’s why: Their results are very similar to the already existing temperature records, which show that the Earth is getting warmer. It’s true. They actually found that it’s been getting warmer than previous results – 1-2ºC compared to the 0.6ºC from the 2007 IPCC report. Here’s a graph of their preliminary data compared to the 3 other temperature datasets. Hard to know what line you’re looking at? That’s because they’re all on top of each other, showing the exact same thing.

So, science wins the day. These results are as much a pat-on-the-back to the scientists at NOAA, NASA and the UK Met Office who have been calculating global temperature, sometimes under high scrutiny for years, as they are for Dr. Muller for going out there, taking them on and, in the end, proving them accurate.

From Dr. Muller himself in the WSJ: “When we began our study, we felt that skeptics had raised legitimate issues, and we didn’t know what we’d find. Our results turned out to be close to those published by prior groups. We think that means that those groups had truly been very careful in their work, despite their inability to convince some skeptics of that…

Global warming is real.”