New research confirms global warming pause never existed.

A New Piece of Research Shows—Once Again— the Global Warming “Pause” Never Existed

A New Piece of Research Shows—Once Again— the Global Warming “Pause” Never Existed

Bad Astronomy
The entire universe in blog form
Jan. 5 2017 8:45 AM

New Study Confirms Sea Surface Temperatures Are Warming Faster Than Previously Thought

sea surface temperatures
Sea surface temperatures in 2001 as measured using the Terra Earth-observing satellite. Observations like this provide an independent measure of temperatures.

Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

In 2015, scientists from the National Oceanographic and Atmospheric Administration published a paper that angered a lot of climate science deniers.* In it, the researchers found that some historic measurements of sea surface temperatures were off by a bit and needed to be corrected. Sounds innocuous enough, doesn’t it?

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  

The thing is, when the researchers applied the correction, the so-called global warming pause disappeared. Poof. Gone.

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For deniers, this was a red-alert situation. The slowdown in global warming was their go-to cry, their hammer they could wield to claim climate scientists were wrong about warming. If the proposed corrections were real, they lose a big weapon.

Fast-forward to Wednesday: A new paper published by a different group of researchers studies the same problem in a different way. What they found confirms the suppositions in the earlier paper: Some ocean temperature measurements were indeed off by a bit, and when corrected, show that the hiatus in warming never existed. In fact, the planet has been warming pretty consistently right through the latter half of the 20th century to today.

Deniers will not be happy about this.

The earlier 2015 paper, titled “Possible Artifacts of Data Biases in the Recent Global Surface Warming Hiatus,” discussed the methods used to measure planetary temperatures, including sea surface temperatures. They found that some older measurements were likely slightly off due to the way they were gathered.

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In a nutshell, the problem is that sea surface temperatures are measured in numerous ways. Historically, a big method is to directly sample ocean water using ships. This is problematic, though, because different ships use different methods, and sample water from different depths. Worse, it’s common to measure the water scooped up by intakes that feed it to the engine room to cool the engines. Ships tend to be warmer than the surrounding ocean, of course, so the measurements done this way are biased to be too warm. The ocean water is actually about 0.1°C cooler than what’s measured.

Not only that, but only some ships bring the water in through the engine room. Others throw a bucket over the side and scoop up water. So you have to be careful and adjust for the difference.

When the researchers applied a correction to the data to account for the measurement offset, they found that the rate at which the ocean surfaces were warming was faster than previously determined. When this was combined with data from land and air temperatures, it showed the whole planet was warming faster, too (oceans cover more than 70 percent of the Earth’s surface, and so strongly affect the overall measured temperature).

sea surface temperatures
Three datasets showing sea surface temperatures: The old NOAA data (blue), U.K. Hadley Centre data (purple), and the new NOAA data (red). Independent measurements using buoys, floats, and satellites show that the new NOAA dataset is the most accurate. It also shows the most warming.

Hausfather et al.

While it had previously looked like global warming had slowed, this correction shows it hasn’t; when they compared the rate of warming to that in the past few decades, they found it was equal; the warming was occurring at the same rate it had since the second half of the 20th century.

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This is the part that, politically, hit like a bomb. For many years, deniers have been claiming that global warming has stopped, or at least drastically slowed, since 1998. This supposed plateau in temperature has been used to make a lot of hay by the anti-science brigade, from fossil fuel–funded “think tanks” to fossil fuel–funded politicians.

Given that denial is practically a party plank of the GOP, this caused quite a stir.  In reaction to the release of the research showing the pause never happened, Rep. Lamar Smith, R-Texas, chairman of the House Committee on Science, Space, and Technology, attacked the NOAA. He started a fishing expedition to try to impede any research it did on climate change, including issuing subpoenas for all emails and data from NOAA scientists, and went as far as accusing scientists of “altering” their data, when really what they were doing was calibrating them, making their data more accurate.

Smith’s McCarthy-esque political shenanigans are ongoing and will no doubt continue. He has shown no signs of abating. And moreover, he’s dead wrong about all this.

The new paper just published will no doubt enflame him. In it, a group of scientists investigated the claims of the earlier paper. They compared the various methods of measuring sea surface temperatures as a way to independently check the historical record. What they found is that the supposition of the first paper was correct: Some measurements were a bit off, and when a correction is applied, the global warming slowdown disappears.

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Zeke Hausfather, the lead researcher, made a short video explaining what they did:

In the new paper, the researchers looked at newer ways to measure water temperature, including buoys that actually sit in the water, robotic ocean probes called Argo floats, and satellite data. These provide far more accurate data and provide a nice, homogeneous sample.

Isolating these methods and using them to compare to the older data, they found the same bias as found in the earlier paper, confirming them. And when they correct for them, again they find the oceans are warming steadily. The “hiatus” was never real. That’s why I tend to call it the “faux pause.”

This is a very big deal. Remember, Rep. Smith is accusing NOAA scientists of falsifying data! That is just about the highest crime you can accuse a scientist of doing.

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And in fact, the opposite is true: These scientists are trying their damnedest to make sure their work is as accurate as humanly possible. They have devoted their lives to this field of study, and they are critically aware of how important this work is, and what its implications are.

Global warming is one of if not the biggest existential threats to humanity. These new results show that—once again—the overwhelming consensus of climate scientists is right. The planet is heating up. And we also know why: It’s our fault. We burn fossil fuels, adding carbon dioxide to the air, trapping warmth, and heating things up. This is having profound effects on our environment, effects we already see.

Despite this, I expect to hear more denial from Congress, from the incoming president, and from state governments as well. This denial will have a profound effect as well. It’s more than just the appallingly shuttering parts of NASA and the attacks on the NOAA. It means years more of inaction toward fixing the problem, and many years more of actively exacerbating it.

There is still hope, though. You can take action. It helps; as we just saw with Congress backing down (for now at least) its gutting of the Office of Congressional Ethics, phone calls work. Make your voice heard.

*Correction, Jan. 5, 2017: This post originally misidentified the National Oceanic and Atmospheric Administration as the National Oceanographic and Atmospheric Administration.