NOAA, NASA to announce 2024 global temperature ranking, climate events

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Good afternoon, everyone, and welcome to this media briefing to discuss NOAA's and NASA's

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analysis of the 2024 global temperature record and other climate highlights from the year.

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I'm John Bateman with NOAA Communications, and I'll be facilitating today's briefing.

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NOAA and NASA are two keepers of the world's temperature data and independently produce a record of changes to Earth's surface

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temperatures based on historical observations over ocean and land. Consistency between these two

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independent analyses and those analyses produced by science agencies and other countries increases our

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confidence in the accuracy and assessment of the data as well as the resulting conclusions.

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We will begin this media briefing with Dr. Russ Vose the Chief of the Monitoring and Assessment

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Branch at NOAA's National Centers for Environmental Information, or NCEI. He will provide a summary

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of NOAA's global temperature and climate analysis for 2024. Following Dr. Vose will be Dr. Gavin Schmidt,

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Director of NASA's Goddard Institute for Space Studies, who will summarize NASA's global

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temperature and climate analysis for 2024 as well. After their presentations, Dr. Vose and Dr. Schmidt

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will be available for questions from the media, which can be asked in the Q&A box located at the

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bottom of your screen. Also, the slides from the presentation will be available for download.

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Just click the link in the event information window located at the bottom left of your screen. We

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will now begin our review of the 2024 global climate analysis with NOAA's Russ Vose.

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Hey, so good afternoon or good morning depending on where you are today. Happy to be here and

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happy to be doing this once again with Gavin at NASA. I'm Russ Vose. I am from NCEI and Gavin is from

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NASA. NASA doesn't need any help publicizing what they're about, but I wanted to start for just a

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minute by telling you just a tad bit more about the National Centers for Environmental Information because we're a little less known. So we archive

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a ton of oceanic, atmospheric, and geophysical data from NOAA and many other sources like 60 petabytes of it. It's all freely available

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and anyone needs it and it includes everything from tree ring data to underwater video data to space weather data. We use it to develop a wide

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variety of use inspired products and services such as the World Magnetic Model, the Global tsunami

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Database, and the U.S. Climate Normals. We're a part of the Department of Commerce and our work supports its strategic objectives, particularly

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those related to data and services for decision makers. And likewise, our work supports many

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sectors of the economy, including primary sectors like agriculture, secondary sectors such as

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construction, and tertiary sectors such as transportation. And right now we're doing a lot of work in support of insurance, retail, and

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architecture and engineering. We also do a little work with global temperature. We've done that for

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a long time and that's why you're all here today. So I'll get to the headline here with the next

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slide. The punchline is it was the warmest year on record. 2024 was the warmest year on record.

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This figure in particular shows the annual global temperature through time from 1880 to the presence from NOAA. Y-axis is the departure from

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the long-term baseline. Each dot is the temperature for a year and the blue bars are the the Katal

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averages. Just a reminder, NOAA and NASA both use surface data, meaning sea surface temperatures

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from ships and buoys and air temperatures from surface weather stations. We don't use satellite data like some other projects and we don't use

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any weather forecast models like Copernicus. Those are great ways of tracking global temperature, but that's not what we do. Again, highlight is

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2024 was the warmest year on record. In NOAA's data set it was 1.29 c degrees celsius or 2.32

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degrees fahrenheit above the 20th century baseline. We were 0.1 degrees celsius above 2023. So a lot of

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groups like Copernicus and the World Meteorological Organization have been telegraphing the possibility that this was the warmest year on record for some

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time. That includes NCEI. Our monthly reports include a statistic that estimates the probability

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that the current year will be the warmest on record and that statistic has exceeded 95% in each report since August. So this is not really

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new news at this stage. It's more of a confirmation for what we all suspected was going to happen.

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Getting back to the figure, you can see the last 10 dots which are the 10 warmest years on record. Go back a bit further, meaning the blue bars,

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to clear that each of the past four or five decades has been warmer than the decade that preceded it. And there's been a steady

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increase in temperature since at least the 1960s and Gabby has a nice figure to shed at and long-term

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increase since the late 19th century. As for next year, while barring some major volcanic eruption or

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other extreme events, our preliminary calculations suggest there's only a 5% chance or less that

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2025 will rank first. But a 95% chance it'll be in the top five. But for the sake of full

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disclosure, at this time last year we said there was only one in three chance that 2024 would be

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the warmest year on record. So it's a tough game forecasting a global temperature. A quick

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description of things that might have contributed to 2024's warmth. Gabby commented on these in

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more detail because it's really more his wheelhouse. One of the obvious ones is El Nino. We shed a warming effect for a couple of reasons.

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Above average ocean temperatures of the tropical eastern Pacific, which is a big area, and drawed over large areas such as... large

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areas such as, excuse me, much of South America, which makes it easier for the land to heat up. El

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Nino ended in May 2024. We felt La Nina conditions emerge just last month. There's been a

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recent reduction in air pollution over the ocean, particularly in the North Atlantic and North Pacific. Shipping regulations implemented in 2020

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reduced the emission of sulfur dioxide, which tends to encourage low-level cloud formation.

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So if you have reduced emissions, that implies fewer clouds and more sunlight reaching the earth, beating the ocean, and warming. There's some

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other near-term contributors that are probably tinier, like the 2022 volcanic eruption in Ponga, which

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put a lot of water vapor into the stratosphere. The sun's technically about at its peak of an 11-year cycle. Polar sea ice has been

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very low levels. Gavin will talk more about that. That allows more energy to hit the ocean rather

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than being reflected back to space. There's been a longer-term decrease in cloud cover.

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Recent study by NASA using the Terra satellite found a small but tangible drop in global cloud cover over the past two decades in both the

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tropics and the mid-latitudes. That's a little different than the shipping thing I just mentioned earlier. The shipping thing sort of

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contributes since 2020. And then, of course, there's been concentrations of gases like carbon dioxide,

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which is 50% higher than pre-industrial levels. Methane and nitrous oxide are also up about 150%

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and 25%, and those obviously contribute as well. So now I hand the mic off to Gavin to tell you the

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NASA story. Thank you very much, Russ. That

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was a great summary. The NASA data as well shows,

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of course, that 2024 was in fact the longest year on record, and the gap between 2023 and 2024 was

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significantly outside of our estimated uncertainties on any one year's estimate. So there's

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really no question about that. Just a little bit of interagency rivalry here, though. I did in fact

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predict that 2024 would be the longest year on record with, I think, a 55% probability

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at the beginning of the year. So that went for us. One of the nice things about the efforts that

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we've done is we've done a lot of work on the uncertainty associated with these numbers.

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We have now a new ensemble of possible reconstructions, which we're seeing a little bit of the

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uncertainty associated with that in there. And that allows us to say things like what's the likelihood

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that this year is more than 1.5 degrees above the pre-industrial, with a little bit more

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confidence than we have been able to do in previous years. But the main conclusions are,

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as Russ said, all of the groups agree,

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regardless of how they put the data together, regardless of what data they're using. So

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this is a very, very robust and solid result.

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All right. Thanks, Kevin. So this next map shows temperatures for 2024. It's in the NOAA analysis.

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NASA will look very similar. Redish areas had above average temperatures for the year.

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Blueish areas had below average temperatures. For this map, the baseline period is 1991 to 2020.

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So temperatures were warmer than average, meaning reddish in color, over the vast majority of the Earth's land surface. The largest warm anomalies

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were in the Arctic, Northeastern North America, and Eastern Europe. North America, South America,

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Europe, Africa, and Oceania all had their warmest year on record. Asia and the Arctic ranked second.

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Overall, it was the warmest year on record for the land surface as a whole. By the way, the U.S.

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also had its warmest year on record. The only other time that's happened, meaning both the U.S. and the globe had their warmest year on record was 1998,

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also another big El Nino year. Much of the ocean surface was above average as well. The largest

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warm anomalies were in the North Atlantic and the Western North Pacific. And again, it was the warmest year on record for the ocean as

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well. The map at the lower left, this little map, tries to put this heat in perspective. You

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don't need to look at the fine details, but anything that's reddish, in other words, most of the planet was much above average. That means the

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90th percentile. The brightest red areas had their warmest year on record, which includes a big

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chonkal planetary real estate between, say, 50 degrees north and 25 degrees south, except for

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the Eastern Pacific. So, emotion areas fell into what's called the Supermarine Heatwave category,

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meaning their daily sea surface temperatures at those locations broke their historic records. The largest such area was in the tropical Atlantic

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and the Caribbean Sea, basically along the northern and eastern shores of South America. But there

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were extensive parts of the Southern Ocean that also had Supermarine Heatwaves during the year, as did portions of the subtropical Western Pacific

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and the Indian Ocean. Some areas had more than 80 Supermarine Heatwave days during the year.

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But for the sake of fairness, it wasn't hot everywhere. Temperatures were cooler than average, meaning bluish in color over some areas

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such as southern Greenland, eastern Antarctica, the southeastern Pacific Ocean, and the Drake

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Passage, which is that ocean area between South America and Antarctica. One other point on the

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map, because this has popped up in the news a little bit briefly, the Arctic and the northeastern North America. Warming in this area sometimes gets

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some attention because of the potential for a more sustained opening of the so-called Northwest Passage, which is a sea lane or multiple sea

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lanes between the Atlantic and Pacific Oceans through the Arctic. Travel through the passage is typically only possible for, I think, a few weeks of the

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year, something small like that. Longer term warming certainly contributes to the possibility of a longer shipping season, but warming

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doesn't prevent thick multi-year ice from flowing down from the Arctic Ocean into the Canadian

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Archipelago, where it can block or choke narrow points along the passage. There's some recent

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evidence that the length of the shipping season has actually dropped in some areas since 2007 for just this reason. But I sort of share this,

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even yet, just to drive the point home that changes aren't as simple as, "Oh, it just gets warmer. The climate system is more complex than

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that." And now back to Gavin, who's going to talk about some longer-term trends. Yeah, I mean,

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the most important thing, obviously not from the questions that we're getting today, but from

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my point of view, the most important thing that our data provides is the longer-term trends,

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because those are the things that are the most predictable and the most important for the

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predictions going forward. And the long-term trends are very, very clear. It's warming more

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over the land than it is over the ocean. It's warming more in the Northern Hemisphere, where there is more land than in the Southern Hemisphere,

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where there is less. And it's warming most of all in the Northern Hemisphere, in the Arctic

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regions. And that's obviously extremely concerning for things associated with the

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Arctic sea ice, but also the ice sheets in Greenland. The only places where we see over

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this now, I mean, this is since 1970, so that's 55 years, is that right?

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The only place that has seen a net cooling is immediately around the Antarctica. And we've been

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doing work on that. And it seems that that is likely to have been influenced by the meltwater

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from the ice sheets changing the stratification in the Southern Ocean. But the pattern of warming

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that you see is in fact very close to what models have predicted for many years. And we are now

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seeing very, very clearly. Russ? All right. Thanks, Kevin.

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What we've got here now is a little video to show for what things look like over the course of the

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year. So this video is showing the departures

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from average by month. So it's like the previous map that I showed only. It's on a month by month basis. So consistent with it being the warmest

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year on record, there was a lot more red than blue on most of the maps. That's not a real surprise. Every month from January through July was record warm with August being a tie.

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In fact, there were 15 straight months of record global temperatures from June 2023 through August of 2024. It's cooled off a bit since then. For

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example, December 2024 was about 0.13 degrees Celsius cooler than December 2023 in the NOAA

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analysis. September through December of 2024, each ranked second warmest. But that's again,

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hardly visible on the maps. As always, there were significant month to month changes in the pattern, particularly over land. For example,

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Antarctica was much colder than normal in January, but warmer than normal in August. Asia was colder

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than normal in February, but warmer than normal in November. And Africa was warmer than normal in March, but much cooler than normal in

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October. This sort of variability is quite normal over land. In contrast, there was a lot less month

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to month change over the ocean, which is also normal, simply because water has a higher capacity than air. As a result, some patterns

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were persistent, such as above normal conditions in much of the Atlantic and the Indian Oceans. Other areas changed gradually, such as the

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tropical eastern Pacific, which was above normal early on, then became cooler than normal. This

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reflects the transition from El Nino conditions to a neutral state, and then in December to La Nina. And now back to Gavin.

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So every year we get asked, you know, why is any one particular year or warmer or cooler or

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different from the trend that we were expecting? And so we try and help you guys out here

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by examining the expected impact of what's happening in the tropical Pacific. So the El

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Nino, La Nina variations, as you know, El Nino is a warm event in the eastern tropical Pacific.

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La Nina is a cool, not quite opposite, but effectively opposite, cool event in the

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eastern tropical Pacific. We started 2024 with a

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medium to strong El Nino at the beginning of the year. And what we can see from a statistical

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analysis of the data going back to the 1950s is that if you start a year with an El Nino

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event, there is a lag by which that heat kind of

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affects the heat around the world. And there's a very strong correlation between the state of

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El Nino in February or March and the eventual annual temperature. And so you can use that

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relationship, statistical relationship, to kind of abstract out what the standard response in the

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annual mean temperature to the state of Enzo would be at the beginning of the year. And as I said,

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we started the year with an El Nino. And so that

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gave us a boost, statistically speaking. And you can see in the graph that we have seen similar

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boosts in, for instance, 1998, 2016, a little bit

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2020, and very clearly in 2024. And the boost

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that you get is for a medium to strong El Nino is around 0.1 degrees Celsius above the trend. And so

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in that sense, 2024 was behaving much more like a

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normal year in that it was responsive. It was, well, it's not really normal anymore. So

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as a departure from the expected long-term trend than 2023. Now, 2023, if you recall, started the

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year with a mile of La Nina. And so it would have been expected to have been relatively cool, a little

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bit cooler than the trend, but in fact was a massively warm year, which took everybody by

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surprise last year. We're not seeing quite such an anomalous anomaly, if you like, in 2024. But it was

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at the high end of what we predicted at the beginning of the year. But there was a very clear

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ENSO signal. But I have, and our analysis

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suggests, that there are other things going on that are giving us a little bit of a boost beyond

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what you would have expected just from the trends and the variations from El Nino. But I think that

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a full synthesis of that really is still to come, and we will be talking about that in the months to come. Russ?

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Thanks, Kevin. Shifting gears here a little bit. So far today, Gavin and I have spoken mainly about

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temperature, and there were a number of truly notable extreme heat episodes last year. I'm in

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the significant event territory now, if you will. Not the long-term stuff, but just the significant individual events that happened. But yes, there

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were a lot of big extreme heat episodes last year, some of which were crazy in Mexico in May when

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the howler monkeys were literally dropping from the trees from the heat. Or Phoenix last year,

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which had 70 days over 110 degrees Fahrenheit. I used to live out there. It was not like that

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30 years ago. Any day over 110 is uncomfortable. You certainly don't want to go for a run in that weather. But 70 days, that's tough. But I'm

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shifting gears. I want to talk a little bit about notable precipitation extremes for a minute, both on the wet side and the dry side, meeting

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drought, because of their dramatic impacts to communities worldwide. Here are just a few

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examples from the map that you see here, but there were many others. In September, there was an

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unusually early storm system that drenched large parts of the northwestern Sahara. Some areas received

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up to eight inches of rain in just two days, which is about what you get in an entire year. In one case, the rainfall filled a lake there that

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had been dry for 50 years. In September, you've all heard about this. Hurricane Helene struck

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the southeastern United States, including the headquarters of NCEI. There were over 200 fatalities, and it was the deadliest

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hurricane since Katrina. From a rainfall perspective, it was probably about a one in a thousand year

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event. The USGS actually estimated that there were over 1,000 landslides in the area and

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considers it one of the worst such events in history. Just a few weeks later in October, there was

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torrential rain in southeastern Spain that led to flooding that killed over 200 people and caused extensive property damage. In some areas,

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over a year's worth of rain fell into sofra a day. Unfortunately, there were many others

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that I don't have time to talk about today because I want to mention a couple of dry examples. One of the real compelling ones this year was South America. It was exceptionally

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arid throughout the year, in part due to the lingering impact of El Nino. It was also the continent's warmest ground record, or at least

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tied for warmest ground record. The NASA Earth Observatory noted that rivers in the Amazon fell to record low levels in October. There were months

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of diminished rains that amplified fires, parched crops, disrupted transportation, and reduced hydro power. There was also an extended dry

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spell in southern Africa early in the year, some areas receiving less than half of the normal rainfall. Again, El Nino was likely a driver and

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above normal temperatures certainly exacerbated the situation. The dry conditions came at a critical time in the agricultural season,

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reducing crop yields and livestock production and caused food shortages and damaged regional

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economies. At one point, Zambia's biggest source of power, something that's called the Caribou Hydroelectric Plant, was operating at less than

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one-tenth of its capacity, which led to days at a time without electricity. These are just

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illustrations of the extreme events that went on last year. There were many others, but having recounted all that, I wanted to clarify a couple

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of things. First of all, we aren't saying that any of these events were caused by changes in the Earth's climates. Extreme events have always been a part

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of the climate system. As an example, us anyone who lives in an area that has a decent chance of dealing with a tropical storm each year like

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Florida or Louisiana. It's also important to note that things like exposure or changes in exposure,

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meaning who or what lies in the path of an event, and vulnerability of susceptible those people and things that are being damaged,

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they can exacerbate the impact of extreme events. In the US, for example, there's been an upper trend in billion dollar disasters due to increases

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in exposure and vulnerability, as well as changes in the frequency of some extremes. We certainly

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expect to see more rainfall extremes in a warmer world simply because warmer air can hold more

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moisture. And in theory, a warmer climate might have worsened some events this year. But to be clear, individual events have complicated a

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particular circumstance that need to be sorted out, which is really on the frontier of science this year.

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One last point going back to global and scale to like use the transition for Gavin.

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According to preliminary data from the Global Precipitation Climatology Project, 2024 was the third-west year on record for

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the globe behind 1998-2016 by the tiniest of origins, meaning 0.22 millimeters. Again, notably,

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El Nino was a major player in both of those years. Back together.

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And now, focused a little bit on the polar changes. So the declines in the Arctic are still

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very steady. We haven't matched, fortunately, the peak declines that we had in 2012. But

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Antarctic sea ice remains on a very, very strong downward trend, and that's having huge impacts

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on the climate associated with the polar

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regions there. People often ask us how much

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faster the Arctic is warming than the global mean. And it's roughly three to three and a half times

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as fast. And that's really been a very big shift

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in the last 40 years. If you go to the next slide,

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you can see the Antarctica is not really the same story until very recently.

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Trends had actually been slightly up, perhaps associated with the

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freshwater that was coming off the Antarctic continent. But somewhat unexpectedly, since 2015,

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we have seen increasing decreases in Antarctic

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sea ice. And while last year's September maximum in 2023 was the lowest on record, the 2024 number

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was right behind it. And so we don't have a great

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explanation for why that trend shifted or whether it's just noise. But that's certainly something

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that we are looking at through multiple different techniques going forward into the future.

26:09

Back to you, Russ. Thanks, Kevin. Back to something completely different again.

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This slide shows ocean heat content from the late 1950s to present. Ocean heat content is basically

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the total amount of warmth, the heat energy that's stored by the oceans. It's essential for understanding and modeling global climate

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because 90% of the excess heat in the US system is actually absorbed by the ocean. Changes

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in ocean heat content are determined using measurements of ocean temperatures around the world at different depths. These measurements

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come from a variety of instruments ranging from things that are called batty thermographs to Argo pro-falling floats to bio logging

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devices on marine mammals such as whales and seals. Yes, I guess we do exploit like animals once in a while for the sake of climate.

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In 2024, the warmth of the world's oceans hit a record. Again, it's the highest since records

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began six decades ago. And the five highest ocean heat content values have all occurred in the last

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five years. There's been a steady upward trend since about 1970. And as with surface temperature,

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each decade has been warmer than the decade that preceded it. But there's less variability from year to year because oceans just they don't work

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that way. There are multiple estimates of ocean heat content. We have a couple of lines on

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here. And I can point out that NASA echo record is consistent with the NOAA record and showing an

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ongoing increase in record levels of ocean heat content. Because changes in the ocean systems

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occur over centuries, the oceans haven't actually warmed as much as the atmosphere, even though they have absorbed again more than 90% of the heat

27:42

since the mid 50s. If it wasn't for the large heat storage capacity provided by the oceans, the atmosphere would have formed much more rapidly than it already has.

27:51

Now back to Kevin. Actually, let me just kind of go back to that last one again. There's one

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more data point there. One of the things that is worth saying is that echo is an ocean state

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estimation, which uses a lot of different data, not just temperature data to calculate the total heat content change. And we have

28:17

multiple versions there. So you can see that there's a clarity in how this is increasing year by

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year. But there is some uncertainty about what you're doing when you're filling in the data. So that

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was just a tiny little point on that. Next slide. Sorry. Yeah, this wasn't updated. One of the

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things that people often ask us is how we know that the surface temperature records that we put together are true. How do we know that these are

28:57

good estimates of what's going on? Well, we have different ways of assessing the temperatures.

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There are two ways that are mentioned here. And they haven't quite been updated to 2024, but the patterns are very similar. So you can

29:12

see what's going on. The trends that you see in the re-analyses, which uses different weather

29:19

measurements, it uses satellite instruments, it uses a weather model to put those things together. You can see that there's higher

29:26

resolution there. But the patterns of change that we see that warmth over land in the

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northern hemisphere, in the Arctic, et cetera, et cetera, is very similar in the reanalysis data

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and in the in-situ surface measurement analysis. And a totally different way of estimating what

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the temperatures are is directly from a satellite. There is an air instruments that has been flying

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on, I think, ECWA, I forget, since 2003. And

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that has a, it's a totally independent estimate of what the surface temperatures are doing. It

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has some systematic differences from the surface temperatures. You can see perhaps the trends

30:18

in the tropical rainforest regions are somewhat

30:24

anomalous. And I think that the cooling in the southern ocean is a little bit exaggerated.

30:31

But otherwise, the patterns, particularly things like that warm band of temperatures across the

30:38

North Pacific and in the Arctic, all of those things are coherent from these very independent

30:46

data series. And so our confidence that the surface temperature data set can be used to go

30:54

back in time with some credibility is boosted by the comparisons with what we can now do in terms

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of comparative analysis with different measurement systems. Thank you.

31:09

All right. Thanks, Kevin. And this is our last slide of the day before we take questions. The punchline here is there are a number of

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groups out there that track global surface temperature and they all tend to sell the same story. Some of

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the other major players include the UK Met Office slash Hadley Center, the Copernicus Climate Change Service, Berkeley Earth, and the Japan

31:30

Meteorological Agency. This figure shows time series for several of those major analyses.

31:36

And despite using some of the different data sources in analytical methods, the results really diverge by much. And they all indicate that 2024

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was the warmest year on record. In fact, using an average of multiple data sets, 2024 was about

31:50

1.55 degrees Celsius above the average for 1850 to

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1900, which is a reasonable surrogate for pre-industrial conditions. So it is likely that

32:02

we have now seen the first calendar year with an annual global mean temperature about 1.5 degrees Celsius. But to be clear, this does not indicate

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the planet has exceeded the 1.5 degrees Celsius target discussed in the Paris Agreement. That

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target refers to a sustained eating multi-decadal average that exceeds 1.5 degrees Celsius. That's

32:22

projected to happen sometime in the 2030s or 2040s. It's worth noting that by coincidence, NOAA

32:29

and NASA were actually slightly below 1.5 degrees Celsius. We haven't had the time to do any

32:35

analysis to investigate that yet. But there was at least one recent paper that found that some other

32:41

global temperature data sets were slightly warmer than, say, tree ring reconstructions over the land areas

32:48

of the northern hemisphere during the second half of the 19th century. And if that's the case with NOAA, for example, then NOAA might have had an

32:55

average for 1850 to 1900 that was a little bigger than it should be. And if that average was a

33:01

little too big, then you're subtracting a number that's too big from the 2024 temperature, which would nudge you under 1.5 degrees Celsius if you

33:08

like to split hairs. But the real punch line here is it was another really warm year. And the

33:16

threshold doesn't exactly mean anything in that context. There's heat. Two other quick points.

33:25

There are groups like NOAA, remote sensing systems in the University of Alabama, that also track temperature, meaning above surface temperatures

33:32

using satellites. This slide doesn't show those. Those are starting in 1979. They all show that

33:39

2024 was the warmest year in record for the lower and middle troposphere. They also show a big jump,

33:44

as Gavin pointed out to me the other day, over 2023, about 3.10 degrees Celsius. This is my final word with one exception. I

33:52

just wanted to emphasize this is, I think, the fifth year in a row. Gavin and I have done this. It's been a pleasure working with Gavin on

33:58

this and a privilege working with NASA. So we're forward to doing it again down the road. Gavin,

34:03

if you want to chime in on the series of green, feel free, and then we can be happy to take questions. Yeah, thanks to us. And obviously,

34:11

likewise. One of the things that's coming up in the questions, and you mentioned just

34:17

now, is really the uncertainty in these numbers.

34:22

And it's worth digging in a little bit as to why any of these things are uncertain. You can see that from the 1960s onwards, there is very,

34:30

very little difference between any of the different methods that are used to put this together. And

34:35

that would include the Copernicus data as well. And so the uncertainty for any one annual year

34:43

measurement in the modern period is around 0.05 degrees Celsius. That's very small. And on a graph

34:51

like this is barely detectable. But you will also see that as you go back in time, there's more

34:56

diversity, right? Because the methods that we're using have to do more work because there are

35:04

more inhomogeneities in the data set. There are more gaps in the data set. There are more areas of the

35:11

world that do not have sufficient data to really constrain what was going on. And so the

35:18

differences that we have in our methodologies, whether we're using EOFs or Kriging or interpolation or

35:26

artificial intelligence now in the machine learning in the new NOAA data set or a

35:34

constrained model, all of those things make more of a difference. And so when you try to estimate

35:41

how things have changed since the pre-industrial, there are more significant uncertainties. And the

35:48

uncertainties associated with 19th century anomalies are around 0.1, perhaps even 0.2 degrees

35:56

Celsius. And it's not obvious that all of the data sets that we have are really capturing all of that

36:03

true structural uncertainty, particularly in the sea surface temperatures. And there was a paper

36:08

very recently that looked at sea surface temperatures kind of in the early 1900s and suggested

36:15

that there may still be some quite significant

36:20

for our purposes, but not really significant in the bigger picture of things. There may still be

36:27

some significant uncertainties in what the global mean sea surface temperatures were doing at that

36:32

point. And of course, going back even further, then the uncertainties expand. And so you cannot expect

36:40

a clean answer for when we will have passed a level like 1.5 or 2 or anything. These are going

36:51

to be things that are clearer in retrospect, but there's a effectively an irreducible uncertainty

36:59

due to the fact that the data collection systems that we had in the 19th century were not as fit

37:06

for this purpose as the data systems that we have at present. And so, yes, so thank you very much.

37:14

I'm happy to join Russ with answering the questions. All right. Yeah, thanks so much,

37:21

Gavin. Thanks so much, Russ. We'll open the briefing to questions right now. As a reminder, to ask a question, please find the Q&A box

37:29

located at the bottom of your screen. Type in your name, your media affiliation, your question, and

37:35

the specific expert you would like to answer it, if possible. Russ and Gavin, just looking at some

37:41

of the questions coming in, you have touched upon a lot of this already in your talk, but it

37:47

probably is going to be good to go over some of this again for some of the folks who need to get these answers. First one is from Isam Ahmed from the

37:57

French press agency, either Gavin or Russ. To what extent is La Nina expected to hit the brakes

38:05

and prevent 2025 from being another record warm year? Yeah, happy to take that. So going with the historical precedent set by the data,

38:22

starting this year with a mild La Nina suggests

38:27

that we will be a little bit below the trend. And since we've been so far above the trend, that implies that 2025 is less likely to be a

38:37

global warmest year. And so my prediction for that is that it will be the third warmest year

38:44

after 2024 and 2023. Having said that, these predictions failed quite badly in 2023,

38:52

and are being stretched in 2024. And so to the

38:58

extent that there are ongoing additional things that are happening, that might mean that the

39:04

predictions that come from that kind of methodology may be biased a little bit low. As I said, this

39:10

is something that we're going to be looking into in a lot more detail in the months to come.

39:16

But I think it is, it would be very surprising

39:22

if 2025 was also a record warm year, but and shocking, in fact, so I don't think it will be.

39:30

Russ. Nothing to add to that. You nailed it, Kevin.

39:35

Thank you. All right. And thanks to both of you. The next question from Kimberly Cartier from the American Geophysical Union. And this is about the 1.5 degrees C

39:46

question. Given the observed warming spike for the past two years, do NASA and or NOAA find that

39:52

the 1.5 degrees C warming limit goal is still attainable? I can make a quick comment, then Gavin can

40:00

chime in. Mine's basically, it's not really our wheelhouse, at least not NCEI's wheelhouse.

40:08

We can document what's gone on. We do work with saying something about what the future might be like. But this kind of wades into like a territory

40:16

of other elements, like what do societies decide to do in terms of like, you know, emissions of greenhouse gases and such. And that's

40:25

not really our wheelhouse. So I'll leave it at that.

40:30

I mean, yes, I mean, effectively, Russ is correct. Even if we will likely exceeded 1.5 this year,

40:42

that doesn't mean that we've exceeded it in the context of the Paris Accord, which is over a longer time period. But I will say that, you know, we

40:55

anticipate future global warming as long as we are

41:00

emitting greenhouse gases. And until we get to

41:05

net zero, we will not get a leveling off of global mean temperature. And so global mean

41:12

temperature will continue to rise as long as we get to net carbon dioxide. And that's something that

41:22

brings us no joy to tell people. But unfortunately, that's the case. Okay, thank you. Next one is

41:31

from James Deneen. This is for Russ. It looks like it's kind of a two-part question, Russ. The first

41:37

part of it is, what is the 1850 to 1900 baseline for NOAA? Do you have that in front of you?

41:46

Yeah, sure. We use the 20th century baseline for our figures. What I can tell you is the 1850 to 1900

41:54

baseline is 0.17 degrees Celsius cooler than the 20th century baseline, if that helps. As far

42:02

as this year's temperature, 1.29 degrees C. Yeah, 1.46 above the pre-industrial baseline. I

42:13

have them all in front of me here. Yeah, 1.46 for NOAA and 1.47 for the GIST temper analysis.

42:22

Wonderful. All right. Thank you, guys. Next question kind of related to this from Eric Rostin. Are NASA and NOAA's temperatures

42:31

meaningfully, in quotes, below 1.5 degrees C?

42:37

Are all the other data sets meaningfully above 1.5?

42:43

Great question. And the answer is no, not really. The spread amongst the models and the

42:49

uncertainty associated with that is about 0.13 degrees Celsius. And so that puts the

42:58

NOAA and NASA numbers comfortably within the possibilities that the real number is 1.5.

43:04

And it's similar for the Berkeley Earth and Hadley Center estimates as well. So I don't know that

43:13

there is a meaningful difference between the different estimates. And so the WMO synthesis

43:22

number, which is 1.55 plus or minus 0.13, I think

43:27

is a reasonable assessment of what the real world should. Yeah, I'll add briefly to what Gavin

43:36

said. The differences between the analyses this year, that's like splitting hairs. I wouldn't get

43:41

wrapped around the axle about those differences. And that's partly why when organizations try

43:47

to say more generally, has the world passed 1.5 degrees C Celsius threshold, they're talking

43:54

about a multi-decadal average. Something that's going to be a more robust number, something that's not going to be nearly as sensitive to little

44:01

differences like this. Okay, thank you, guys.

44:06

We have another question. And again, you've been kind of answering some of these as we've been going along. So there may be some information

44:13

that you have to repeat. But this is from Seth Borenstein from the Associated Press. A two-part question. It says, Gavin, what

44:20

amount of the warming comes from the El Nino Southern Oscillation? This year about 0.1 degrees.

44:30

Wonderful. Thank you. And then the second part for either NASA or NOAA, and you guys did touch upon this. Why are both NASA and NOAA

44:40

only the only ones of the major monitoring teams not to exceed the 1.5 threshold?

44:48

It's related to the sea service temperature data that we're using. So both the NOAA and the NASA

44:54

data use the ERSST-5 version of the historical

44:59

SST data. So that's the ocean components. The Hadley Center and Berkeley Earth use a different SST

45:11

product. But really, there's only two products being used. And so one of them is a little bit

45:18

warmer than the other. But it's very unclear which one is most accurate. And so people who are

45:25

looking at sea service temperature reconstructions have been making a point very vociferously

45:31

in technical meetings recently that we need more and better understanding of the

45:39

uncertainties in that product. So the reason why R2 products are a little bit low and the other two products

45:47

are a little bit warmer is almost entirely due to the SST data set that's being used. The only

45:54

thing I'd add to that is we've been using that data set since, for at least five years now, in our

46:00

global analyses. So there's nothing new here. I'm a little concerned that some might look at

46:06

NOAA and NASA being below 1.5 and thinking that something's up with that. And there's nothing

46:12

up with that. We've used the same ocean data for years now. Yeah, I mean, there's real genuine

46:18

uncertainty about what 19th century sea service temperatures look like. We had very few

46:24

ships going anywhere close to the Southern Ocean. At that point, we had very sparse coverage in

46:30

most of the Pacific or in the South Atlantic. And so

46:35

you don't know what you don't know. So those are

46:42

real issues that are not going to go away anytime soon. Okay, thank you guys. Another question coming

46:50

in from Global Brazil from Marco Brito. To what extent can we say that wildfires and other extreme

46:57

events or anomalies are becoming a new pattern or new normal? To quite a large extent, we have

47:08

done now collectively hundreds of analyses of

47:13

specific extremes. We have done collective analyses of all the different patterns of

47:23

rainfall and heat waves. And it's very, very clear that the heat waves that we're seeing

47:29

would not have been happening without the anthropogenic climate change. The intense

47:35

rainfall increases that we're seeing almost everywhere would not have been happening without

47:40

the anthropogenic climate change. The signal in wildfires has been slow to emerge, but it is

47:49

very clearly emerging, unfortunately. So

47:56

we are seeing changes. And for a long time,

48:02

the global mean temperature changes were a bit of an esoteric thing. Nobody lives in the global mean.

48:08

But the signal now is so large that you're not only seeing it in the global mean, you're not only

48:13

seeing it at the continental scale, you're not only seeing it at the regional scale, you're seeing it at the local scale. You're seeing

48:19

it in local weather. And we have collectively,

48:26

my colleagues at NASA and JPL, your whole lab this year have been at the very sharp end of some of

48:36

these events whose intensity and impact has been juiced by anthropogenic climate change. And so

48:45

this is no longer an esoteric academic exercise for us. This is now quite personal.

48:55

Good. Thank you so much, Gavin. Let me see what we got here. It looks like some more questions are coming in. This could be for

49:03

either one of you guys, Russ or Gavin. How are average temperatures around the globe measured and in what locations? Do you use

49:11

satellite measurements? Yeah, I grabbed this one quickly. Over the land surface, we use

49:17

air temperatures from near surface weather stations, which are scattered all over the world,

49:23

tend to be more populated areas. There's, for example, not that many in Antarctica, but there are some. Over the oceans, it's sea

49:31

surface temperatures, which are measured historically like, say, 19th century and early 20th century on

49:36

ships. They usually, they would just take a bucket, dump it in the water, measure the sea surface temperature over time that's been more sophisticated.

49:44

Ocean temperatures being measured through like engine intakes on ships. Now there's like buoys,

49:50

cargo floats, things like that that are even more precise that measure sea surface temperatures. We don't use satellite data in our analysis.

49:57

They're wonderful. We have nothing against them, but these are just basically derived from more traditional observations because they go back

50:03

further in time. Yeah, I mean, we use the satellite data to, as we mentioned earlier on,

50:10

to validate the efforts that we're doing to make sure that there's no,

50:15

there's no in homogeneities that are crept in or non-climatic issues with such as like

50:22

Urban Heat Island. So we spend a lot of time trying to make sure that the data that we have is

50:28

representative of larger areas and as far as we can tell it is.

50:37

Great, thanks guys. Let me see what else we have here.

50:44

All right, it looks like Karen Rives from S&P

50:51

Global Commodity Insights. I'm hoping I'm pronouncing that correct. Interesting question. This year

50:59

it appears that we all tried to coordinate the release of our global reports with the international agencies. What prompted that?

51:08

Well, what prompted it was a desire to be a

51:14

little bit clearer in terms of what message goes out to the public. We coordinated with the EU

51:23

Copernicus services, such that we all released data today. But it wasn't that big a deal in

51:33

terms of coordination. But we have been coordinating I know we're at NASA now for at least over a

51:41

decade and we've been coordinating as well with the HABBIE Center in Berkeley Earth for most of that time as well. We're not rivals, right?

51:52

We're all kind of looking at the same thing from slightly different views and the best thing that

52:00

goes out to the public and to the media is the subtotal of all of that information. Because we

52:08

learn a lot when things when they line up, that tells us that something is very robust.

52:14

And when they diverge, it tells us that there's still some real uncertainty there. And so that's very useful information for

52:21

people to know. And the coordination of these releases and of these efforts is really in

52:29

order to make that abundantly clear for everybody. Yeah, spot on. The only thing I'd add to that is

52:38

just expressing our appreciation to all the other groups for being willing to coordinate because that does put some pressure on some groups because

52:44

you're trying to get the data that are rolling in at the last minute and you have operational processes that are running and it's not always

52:50

so easy to make happen. And it does have some stress. So we appreciate everyone doing that.

52:56

And a particularly shout out to like Copernicus, because they're a slightly different position where their numbers are available a tad earlier.

53:02

And they were willing to like hold on so we could all do things at the same time. So we really appreciate everyone being on the same page.

53:11

Yeah, we certainly do. Thanks, guys. Next question from Nippon TV. First of all, thank you so much

53:17

for the wonderful presentation. What can you say about potential changes to the great ocean currents

53:23

like the AMOC and how that might factor into global service temperatures down the road?

53:30

Yeah, so we don't monitor AMOC ourselves. I mean, there is a monitoring effort that's run out of

53:37

the UK, the rapid array. And it shows a lot of inter-annual variability. There's a very slight,

53:43

though not quite significant decline in the AMOC. But that's really something for the future.

53:51

Yeah, I don't really have anything else to say. Okay, I'll move on unless you have anything to add Russ?

54:01

Okay, the next question is coming in from Japan Broadcasting Corporation, Mikio Tanabe.

54:09

This is a question for either one of you. The probability for 2025 to be one of the five

54:16

warmest years is estimated to be about 96%. Can you explain or perhaps review a little bit as to

54:22

what made you arrive at this conclusion? Sure,

54:28

briefly. We have a... We did some work about a decade ago that just looks at the shape, the

54:34

nature of the global time series and the things that drive it like ocean temperatures and such.

54:39

And so it looks at the persistence of things and the variability around that. And it does a

54:45

reasonable job of sizing things up. And that's how we came in 95-96% chance to be in the top five years on record.

54:56

All right, thank you. And I just want to remind folks, I have about five more minutes left to

55:02

take your questions. It looks like we have a few more. From the new scientist, Russ, you mentioned

55:07

official US breach by late 2030s and 2040s. I'm

55:13

sorry, not US. Let me read that again. You mentioned official 1.5 breach by late 2030s or 2040s.

55:20

Seems like researchers think it might come earlier than that. What is your perspective?

55:27

Well, I suppose it could. It really depends upon how things progress over the next decade.

55:33

It's possible, but that's sort of the best guess as of a couple of years ago with the Intergovernmental Panel and Climate Change

55:41

Assessment Report, the same 2030s or 2040s. But if we keep having warm years like the last two,

55:47

then that happens earlier. But I'm personally pulling for Gavin's prediction that we're like third and we don't get there quite as fast.

55:56

Thank you, Russ. And it looks like one last one,

56:03

and they said they know we're running late. So apologies if you have the time. I'm wondering what makes either one of you confident about

56:10

the onset of La Nina. And could you try to explain in simple terms why you're confident of it and

56:17

why some other agencies may not have yet called it?

56:23

So we monitor the La Nina. The ENSO Outlook is now being run out of

56:30

gifts. And so they use multiple initialised

56:35

models, both dynamic and statistical, to expand out what we expect. They have a very good track

56:43

record in keeping track of the state of ENSO.

56:49

There's a bit of a predictability barrier in the spring, so it's hard to see what's going to happen

56:54

beyond April or May to see what would happen in the second half of the year. But right now,

57:00

we're in a mild La Nina, whether it meets one

57:06

person's threshold or another person's threshold is a little bit unclear. But it's not a very

57:11

large perturbation at this point. And it's not quite

57:16

clear how that's going to evolve over the rest of the year. Come and ask us in like April, and we'll

57:23

have a better idea of how that's going to pan out for the rest of the year.

57:31

Anything else?

57:45

John, you're muted. Thank you. I apologise for that, guys. We've got

57:53

a couple more minutes here. One final question. John Todd Waterman from the Tennessee Sierra,

57:58

and it looks like, what do you expect the relative future impact of global warming and cooling feedback loops to be, particularly whether or

58:06

not they would accelerate each other? Well, I mean, there are feedbacks to

58:15

global warming. We're very aware of the increasing amount of water vapor, which is a positive

58:21

feedback, an amplifying feedback, the change in sea ice, which is also an amplifying feedback,

58:27

the melt in the permafrost, which releases greenhouse gases, which is another amplifying feedback. And that's measured, that's moderated

58:33

by the negative feedbacks, the dampening feedbacks associated with more energy going out to space,

58:41

perhaps shifts in the clouds. Those are things that are kind of working out all the time.

58:49

We think that, well, we know that the net

58:55

feedback is amplifying, so it warms a little bit more than you would have expected just from the

59:02

radiative transfer associated with carbon dioxide on its own. And that's playing out right now.

59:11

We're seeing some very interesting patterns of dynamical cloud feedbacks. So the clouds are

59:18

moving poleward in the storm tracks that may be having a big impact on the measured albedo,

59:26

the reflectivity of the planet that we've been measuring from NASA satellites. But yeah, I mean,

59:34

knowing how all these things are playing out is really the bread and butter of the climate modelers, which when I'm wearing a different

59:41

hat, that's me as well. But other groups as well. And we're very interested in seeing exactly how

59:49

these things are playing out, even on a year by year basis. But unfortunately, they're not

59:55

going to come and save us from ourselves.

1:00:01

Okay, anything you want to add on to that, Russ? If not, it's right at the top of one o'clock. Nope, we're good. All right. Well, thank you guys.

1:00:10

Thank you very much Russ and Gavin for taking the time to present and give your feedback to

1:00:15

the reporters. We're going to wrap up the press briefing at this time. I'd like to thank all of our presenters and participants for joining us

1:00:22

today. I just want to remind you that a recording of this media briefing will be available on

1:00:27

Monday on the online media advisory on NOAA.gov, as well as on NOAA satellites YouTube channel.

1:00:32

And of course, if anyone from the media has additional questions or informational needs,

1:00:39

please feel free to reach out to me and I will spell it. nesdis.pa at noah.gov.

1:00:46

That's n-e-s-d-i-s dot ga @ n-o-a-a dot g-o-v.

1:00:56

And my contact information is also available in the media advisory. Thanks for joining us today.