No ‘Pause’ in Global Warming: Oceans Heating Up and Sea Levels Rising at Alarming Pace
UC-Berkeley climate scientist Zeke Hausfather details the findings of a new report that confirms NOAA findings about climate change
KIM BROWN: Welcome to The Real News Network. I’m Kim Brown in Baltimore.
In the summer of 2015, scientists from the National Oceanic and Atmospheric Administration published a scientific paper correcting previous data on ocean temperatures since 1998, suggesting that sea temperatures were almost double the temperatures of previous NOAA findings. Now, the updated research caused an uproar from climate change deniers, who had actively publicized the previous finding as a global warming pause, or climate change hiatus.
The House Committee on Science, Space, and Technology, lead by Texas Republican Lamar Smith, filed a subpoena for the NOAA scientist’s emails, accusing them of altering data for political ends. Now a new independently produced study confirms that the planet and the sea surfaces is indeed warming, consistent with the controversial NOAA study, and that a pause in global warming did not occur. And with us to discuss the new study, which is titled, “Assessing Recent Warming Using Instrumentally Homogenous Sea Surface Temperature Records.” That’s a little bit of a mouthful.
We’re joined by one of the study’s authors, Zeke Hausfather, who is a climate scientist, and energy systems analyst, with Energy & Resources Group at the University of California, at Berkeley. He’s also a research scientist with Berkeley Earth, which is an independent, non-profit. And his research focuses on instrumental temperature records, model observation comparisons, and climate impacts of energy systems.
And Zeke is joining us today from San Francisco. Zeke, thanks so much for being here.
ZEKE HAUSFATHER: Thank you. It’s a pleasure to be joining.
KIM BROWN: So, Zeke, according to NASA scientists that, you know, 2016 is indeed set to be the warmest year on record since 1880, when global record-keeping began. Now, this would mark the fifth time in the 21st Century that a new record high annual temperature has been set. And to date, including 2015, 15 of the 16 warmest years on record have occurred during the 21st Century. So, Zeke, based on your study, and NOAA’s, can we say with certainty that a pause or a hiatus in global warming, did not occur between 1998 and 2013, as climate changer deniers would have us believe?
ZEKE HAUSFATHER: So, we certainly can say that there has been no pause up to present. As you mentioned, the last three years in particular, 2014, 2015 and now 2016, have been the three warmest years on record. Now, it’s always possible to cherry-pick a particular period of time, say start from a high temperature in the 1998 El Niño, and go to a low temperature in 2012, and say, “Oh, the trend over that period is a little lower than the previous trend.”
But you could do that for a lot of previous periods as well, and it doesn’t necessarily mean that warming has in any way slowed down, or stopped. It just means that there is short-term variability on a decadal time scale, caused by things like El Niño events. And some dynamics of ocean currents that can make it warm slightly slower, or slightly faster, for short periods of time.
But over longer periods of time, particularly over the last 30 or 50 years, we see warming continuing unabated. And today we can say that the rate of warming from 1998 through today is exactly the same as the rate of warming from 1970 through 1998, as well as from 1970 through today. So, at this point, there’s no evidence in any sort of pause through present.
KIM BROWN: So, tell us a bit about the background of all of this. So, how did NOAA and other government research organizations get it wrong in the first place? And what did they do in the controversial paper that corrected that?
ZEKE HAUSFATHER: Sure, so taking the temperature of the Earth is a bit of a challenge. It’s not as simple as just sticking a thermometer everywhere and reading what the thermometer says. The big issue that, sort of, NOAA ran afoul from the last few decades, was changing the way… or the way that we’ve measured ocean temperatures has changed a lot. So, back in 1990 we got about 95% of our ocean measurements from ships, particularly from ship engine intake valves. So, ships pull in water through the hold to cool the engine, and they stick a thermometer in that water before it reaches the engine.
Today, however, almost all of our ocean temperature measurements, or at least the vast majority, come from buoys. And these are little floating instruments that drift around in the ocean. They take temperature of the top of the water. They sit directly in the water and they send their data up to satellites in real time. Now, the problem is, ship engine rooms are warmer, unsurprisingly, than the ocean around them. And so, if you measure temperatures in the engine room of a ship, you’re going to get a temperature that’s slightly warmer than say, a buoy sitting outside that ship will find, because it’s sitting directly in the water.
And so, what was happening is, NOAA sort of smooshed together all of the ship data, and all of the buoy data, without any sort of correction for the offset between the two. So, you take a bunch of warmer data, you stick a bunch of colder data to the end of that, you end up with a sort of, spurious cooling trend, or at least a reduction in warming trend in the data. Whereas, if you just look at the ship data, or if you just look at the buoy data, each of them is warming apace. It’s when you combine them without accounting for the fact that each instrument reads temperature a little bit differently, that you get a cooling bias.
So, that was the big factor behind the underestimation of temperature in recent years by NOAA. And so, what their scientists did in 2015 is two things. One, they corrected for that offset. So, they said, “Okay, whenever we’re measuring data from ships, it’s about .12 degrees centigrade, it’s almost .2 degrees Fahrenheit, warmer than we’d get from a buoy measurement. So, we’re going to take that into account when combining these measurements together.”
The other thing they did was they decided that the buoy data was more reliable than the ship data. So, every ship is different, travels at a different speed, has a different hold depth, and all of those things will affect how the temperatures are read.
Whereas buoys, they’re all the same instrument. They’re specifically set up to measure temperatures globally. So, NOAA decided that if there’s a ship and a buoy in the same general part of the ocean, they’re going to prefer to use the data from the buoy over the ship. And so, those are the two things that, combined, lead to a significant increase in the estimated rate of warming.
KIM BROWN: So, how are you and your colleagues able to verify the NOAA findings?
ZEKE HAUSFATHER: So, as I mentioned earlier, one of the challenges with NOAA is, they’re trying to combine data from multiple types of instruments into a single record, which you need to do if you want to have a long-term record back to say, 1880. But whenever you do that, it involves judgement calls of how to adjust for changes from one instrument to the other. Our sort of big idea was — what if we don’t combine data from multiple types of instruments?
So, the period on which everyone is focusing, the last 20 years, we have a wealth of new ocean temperature data that we’ve never had before from satellites, from buoys, from robotic Argo floats — these neat robots that dive deep down in the ocean and come back up. And we have enough data now that we can create a global sea surface temperature record just from buoys, without any ships, or any other instruments involved. We can create a record just from satellite data without using anything else. We can create a record just from these Argo floats without using anything else.
And the benefit of these instrumentally homogenous records, as we call them, is they don’t require any adjustments for changing measurement types. And when we compare these three records we created, to the old NOAA record and to the new NOAA record, we find that they agree almost perfectly with the new NOAA record, and they show a strong cooling bias in the old NOAA record.
From a scientifically important standpoint, they also show a significant cool bias in some of the other ocean data sets, like the UK Hadley Centre’s data set, which is widely used. And that means that a couple of the global temperature records that use the Hadley data, set right now, are running too cold compared to the ones that use the more accurate NOAA data set.
KIM BROWN: So, generally, Zeke, have the methods improved for verifying climate change data and research?
ZEKE HAUSFATHER: Definitely. I mean, we have much more, and much higher quality, data today than we’ve ever had before. We’ve invested a lot of money in automated measurement systems that are widespread around the Earth’s oceans, as well as in the air above us, through satellites. And we can be a lot more confident in temperatures in the last say, 20 years, because of this wealth of data, than before that period.
I mean, that said, we still have a high confidence that our estimates of temperature change since 1880 are correct, you know, plus or minus maybe 5% uncertainty. It’s just in the last two decades we eliminate most of that uncertainty. So, we’re very certain about what’s happened in the last 20 years.
KIM BROWN: So, can you talk a bit about the effects of climate change on the ocean, in terms of absorbing Co2 and other greenhouse gases?
ZEKE HAUSFATHER: So, there are a couple important effects of climate change on the oceans. One big one is ocean acidification. So, about half of the Co2 that humans emit into the atmosphere gets absorbed by the ocean and the land. And most of that gets absorbed by the ocean. And when the ocean absorbs this carbon dioxide, a certain amount of it becomes carbonic acid and it affects the pH, the acidity essentially, of ocean waters.
Now, a lot of folks are concerned about ocean acidification because it can affect the growth rates of various calcium-based organisms, like coral, or shelled sea creatures. It can affect fisheries. It can affect fish populations in general, and so there’s a lot of concern about how the changing acidity of the ocean will affect ocean life in the future. Another issue that happens with climate change in the oceans, is simply the ocean’s water is getting warmer. And a lot of organisms, particularly in the tropics, are very sensitive to small changes in temperature.
So, coral reefs, for example, on average the difference between summer and winter temperatures in places with coral reefs, is about two degrees. And so they’re really not adapted for temperatures widely outside that range.
And so we saw this year, for example, we lost upwards of 15% of all the world’s coral reefs due to coral bleaching. Where the temperature got so high, that the organisms that live in the coral that help provide food to the coral polyps died. The corals turned white, bleached, and large portions of the Great Barrier Reef, for example, are now dead.
Now, these reefs can recover given enough time. But the problem is — what is an extreme event in, say 2016, is going to be an average event by year 2025. And so, when we start having these extreme heat events every single year, and they become the new normal, it’s really hard for coral reefs and other eco systems to recover.
And then finally, the third thing we have to worry about with the oceans is, sea level rise. So, climate warming affects the oceans in two ways. One, is it melts land based ice, so, ice sheets, glaciers — and that water runs into the ocean, contributes to rising sea levels. The other thing is that as water warms, it expands. Warm water takes up more space than cold water. And so, as the oceans warm they also just expand due to the expansion of water itself. And so, there’s still a fair amount of uncertainty on how much the sea level rise we can expect globally in the next century, but the latest models tend to suggest somewhere in the range of one to three feet of sea level rise, if we continue emissions unabated, without, you know, changing our behaviors in the next 100 years.
And one to three feet of sea level rise could cause serious flooding and damage to a lot of places. And a lot of coastal cities would be partially under water. It would also make storm surges that more dangerous. Because now if a storm surge comes, you know, two feet below the top of the levee, if we have three feet of sea level rise, it’s going to be over the top of the levee. And so there will be a big need to invest in additional costal defenses and things like that.
KIM BROWN: All very sobering information there, Zeke. So, could we reach a point where the oceans can no longer absorb any more Co2, and if so, what would the effect be on the Earth’s atmosphere?
ZEKE HAUSFATHER: So, we’ll never reach a point where the oceans can’t absorb any more. That said, under higher levels of atmospheric carbon dioxide, like we might reach by 2070 or 2080, if we don’t reduce emissions, we could see a case where the oceans can’t absorb as much anymore. So, they start saturating, the surface water has absorbed so much Co2 that they’re not able to pull in as much as they used to. And in that case, our emissions would have a bigger effect on the atmosphere.
So, as I mentioned earlier, right now about half of the Co2 we emit stays in the atmosphere, the other half gets absorbed by the ocean and the land. In a world where we emit so much that the oceans saturate, then we’d end up with less than half, maybe only 40% or 35% of the Co2 being absorbed by these natural sinks. Which would mean the amount in the atmosphere would increase more quickly. Which would mean we’d have more warming of the land and of the oceans for that matter.
And there’s some feedbacks there that are a little worrisome, because as the ocean warms, it also can absorb less carbon, because warm water can hold less carbon dioxide than colder waters. And it makes it more difficult to reduce emissions in the future, because the rate at which the oceans will be taking up emissions from the atmosphere will be slowed for a long time.
KIM BROWN: So, let’s shift gears a bit and discuss the political backdrop. Because now we have Republicans and climate deniers running all three branches of the US government, President-elect Donald Trump and members of Congress have discussed eliminating the Earth Science Divisions of NASA and NOAA. NOAA could also potentially be on the chopping block.
So, how important is the science that they do, in terms of tracking climate change, as well as extreme weather for independent research, and also the American public?
ZEKE HAUSFATHER: It’s absolutely critical. I mean, none of us can afford to launch satellites that monitor the Earth. Pretty-much all of Earth’s observation systems, that we have today, are funded and provided by U.S. government agencies. Almost all of them, Europe has a few, but the US has really taken the lead on this. And the funny thing is, you know, the word we’ve gotten from Donald Trump himself is that he’s not sure about climate change. And if you’re not sure about climate change, you need more observations, not less. You need to understand what’s going on better, not cut all of our observation systems.
So, I feel like, if people think climate change is more uncertain, they really should be focusing on getting better data not, you know, getting rid of our ability to monitor it. Because then we really won’t know what’s going on. It’s definitely worrisome, particularly for folks working in those agencies who are, you know, as our study showed, good scientists doing good work. They’re not, you know, politically motivated or trying to cook the books in any way. And hopefully, at the end of the day, you know, the cuts will be minimal.
There are civil service protections. It’s hard to completely change government agencies overnight. They’re very large and slow moving organizations. And even during the Bush administration, you know, it wasn’t great for climate research, but we didn’t see wholesale upheavals. That said, back then, climate was less of a political issue. So, it’s definitely worrying. A lot of folks are, hoping for the best and planning for the worst, and we will have to see what happens.
KIM BROWN: Indeed. Well, we’ve been joined with Zeke Hausfather. He is a climate scientist and energy systems analyst with the Energy & Resources Group at the University of California, at Berkeley. He’s also one of the authors of the recent study that has been published, it’s called, “Assessing Recent Warming Using Instrumentally Homogenous Sea Surface Temperature Records”.
You can find a link to it at the bottom of this interview. Click on it, comment on it. And give us your thoughts and your comments. Zeke, we really appreciate your time today, thank you.
ZEKE HAUSFATHER: Thank you.
KIM BROWN: And thanks for watching The Real News Network.