Select text to annotate, Click play in YouTube to begin
00:00:01
[Music] this is Star Talk Neil degrass Tyson here your personal astrophysicist we're going to do a climate update this will be fast
00:00:15
catching up on the latest knowledge of what the state of the world's climate is let me bring in my co-host Paul mrio Paul good to have you back man good to see you so I don't how many people don't
00:00:28
know this but right up the street from the American Museum of Natural History is a branch of NASA called the Godard Institute for space studies which focuses primarily on planetary
00:00:40
atmospheres I think we can count Earth as a planet here so that counts we have with us and it's not his first rodeo Gavin Schmidt Gavin welcome back to Star Talk hi thanks a lot for having me back
00:00:54
there's a lot to talk about you're you're only the third director of that storyed institution it's been around for at least 60 years uh that's exactly right yeah about 65 years now so you're chief a climate scientist and climate
00:01:06
modeler there's a climate you know in any given instant but if you have to predict it you need a computer to help you do that so a climate modeler is someone who programs computers to get
00:01:17
some insight as to where things are versus where they will be and why things are doing what they do like how how will the bits and pieces fit together so so we use the models for that we use the
00:01:31
models for you know explaining you know how much of this is our fault how much of it is is natural cycles and then Gavin it's all your fault we we know this well judging from the comments on my
00:01:43
Twitter feed I think I think some people might agree with you yeah who runs the model that says all of this is a hoax and doesn't exist is yeah there there's no there's no such model it you do this spoken like a true
00:01:56
conspiracy theorist good for you yeah that he has to say that yeah exactly wa so Gavin you know you responded to our distress call you know we put up the bat signal over the Gard Institute which is
00:02:08
right just south of Columbia University just off of Broadway we put up a distress call because we read that there was a report a NASA Noah report Noah as
00:02:19
in National Oceanic and Atmospheric Administration not Noah the man Noah working for he he he did know a lot about
00:02:31
floods he could predict a flood okay he knew his water that guy so we read in this report that 2023 was the hottest year on record indeed could you just break down for us how is that measured
00:02:43
by how much is it the hottest is this a trend uh or is it a fluctuation what's going on we want to keep track of what's going on on the planet right so we have lots of uh senses we have lots of we have weather stations all over the world
00:02:55
we have uh uh ocean uh ships and and boys floting around measuring uh everything uh and we want to put all these things together just just to be clear I don't know what accent you're coming from you said but you have boys
00:03:08
in the ocean and I to to booies booies Oh I thought I thought you had like some kind of AI or something my boys my boys they in the ocean measuring stuff yeah and we've
00:03:21
been trying to put that together since the 1980s we have the the longest running time series of of global temperatures that uh that that anybody has had um and we started doing that in
00:03:34
the 1980s just to be clear two-thirds of the Earth surface is covered by ocean when you say you have ocean buys are they measuring the ocean temperature at the locations of those bullies or the air temperature above the ocean at those
00:03:46
locations they're measuring the uh the ocean temperature at the surface and then down to about uh 700 MERS and they come back up some of them go down a little bit further and they come back up and they radio their information so these are bobbing buoys they are bobbing
00:03:59
buoys yes wow okay put all of that information together and uh you know with the historical data you can push this back to the late 19 century and so you can get a record of how uh warm the
00:04:11
planet has been uh both globally and and regionally uh over the last you know 150 odd years and 2023 uh was the warmest of all of those years by a record margin
00:04:25
right so not just a record but it was the the biggest new record that has ever been set uh and so that's uh that's a very big deal because it comes on the back of a long-term Trend uh
00:04:38
particularly since the 1970s of steadily increasing decade by decade temperatures that are that's driven by what we've been doing right so the the increases in carbon dioxide increases in methane and
00:04:52
other greenhouse gases the predictions were that they it would it would heat it but not that much right because uh they we were starting with a linia phase right but right so you didn't see this coming but not not even your models no
00:05:06
no we didn't and so that's that's very discomforting yes it should be we thought we had a pretty good idea about how you know the long-term trends uh are affected by things like the greenhouse gases so we we we think we've got that
00:05:19
down uh and then we have uh you know 150 years of History where we've seen when you get an El Nino event at the beginning of the year then that makes that year and then when you have a Lino which is a cool event in the tropical
00:05:33
Pacific when that happens you have a cool year and El Nino and L so the El Nino comes from uh it's it's Peruvian it's the it's the Christ child arriving at Christmas and and the the El noo
00:05:45
would Peak uh around December January so that's that's uh it was something that would arrive uh around the holiday season and so that's what it was called and then the the lanin is just the opposite phase is it is it six months
00:05:57
later uh no so that Peaks around Christmas as well oh it's just which whichever one it is that that's doing it got right so that that Peak around Christmas that tells you what's going to happen the next year right and that was
00:06:08
that was a very useful uh heuristic and and you know and for many many years you would make a prediction based on that oh it's going to be a little bit warmer than the trend a little bit colder than the trend and it worked and it's not it's not like it's peaked either because
00:06:21
isn't it like nine more months it will over the next N9 months or so beyond this point it'll continue to get hotter but but this this this year Well in 2023 total failure total fail no no no you you failed but still in the right
00:06:34
direction okay just total failure would be oh it's going to drop the temperature dropped by five degrees and went up by two and a half degrees that would be total failure he just well okay so maybe I'm being a little bit harsh on myself I mean you know uh but I think you should
00:06:47
be harsh on yourself this is our lives at stake here I think you got be harsh on yourself well fair enough fair enough like it's this is a big deal and so uh one of the reasons why why we put out the report and and why we raised the the
00:07:00
notes of cautions that we did is because when we don't understand something right there's science to be done but it also means that our predictions of the future suddenly become less certain right you
00:07:11
know so we're we're not sure what's going to happen with 2024 I have I have a prediction for that based on what used to happen but like maybe what used to happen is no longer what's actually
00:07:23
going to happen and that's that's like I said uncomfortable do you guys factor in the Solar because the sun is on its way towards solar Max right now yes it is and so the sun there was there were
00:07:36
predictions of what the solar cycle would be and uh and and and this solar cycle is is kind of ramped up a little bit faster it's a little bit bigger than we uh uh than the than the than the solar people uh predicted uh so there's
00:07:48
still mysteries about how to predict the solar cycle just to be clear the solar cycle is 11 years yeah so we had a we had a solar Min uh a minimum value for the solar radiation uh around uh you
00:07:59
know 3 four years ago uh and we expect the maximum uh to occur in two or three years from right so that's headed up and so at solar maximum there's higher
00:08:11
energy output of the sun especially at high energy wavelengths yeah so so it affect it very um it amplifies ozone uh so you get these these very large temperature shifts in in the
00:08:23
stratosphere uh at the surface you you can see you know it's it's a pretty small number it's it's around you know 05 to 0.1 Dees celsus so it's about 02
00:08:35
degrees Fahrenheit from from minimum to maximum so it's not a huge number but it is a driving force that's in your models absolutely yeah yeah no it's something that we've been uh that yeah we've been looking at that for a long time what
00:08:47
input parameter do you think you either missed or didn't adjust accurately to have predicted this this uptick right great great question um so one of the most mysterious things that we we don't
00:08:59
really have great data for yet uh is uh what what the what the particles in the air are doing so these are called aerosols um some of them are you know dust that's been swept up from the deserts some of it's salt that's been
00:09:13
kind of swept in from the sea uh but a lot of it is air pollution right so uh things that we get from burning uh burning coal or or or or industrial processes or or sometimes from agriculture that's putting a lot of
00:09:25
particles pm2.5 sort uh into the air so these these are particles 2.5 microns and smaller uh yes yes but this PM stands for particulate matter
00:09:36
particulate matter and Micron is one 10 the minus 6 one millionth of a one millionth of a meter so that's 1,000th of a centimeter 100 yes something so that's small okay good but the things
00:09:50
that that that do the most amount of damage when they get into your lungs so so there's there's uh there's been changes in uh in in in particulate matter in the air because we've been we've been writing laws and saying no
00:10:02
you can't pollute quite as much you have to be you have to do cleaner stuff so we've seen uh We've we've seen drops in in these uh in these aerosols and the net effect of these aerosols is to cool the climate a little bit because they
00:10:14
interfere with the sun's radiation they reflect a lot of it back to space uh and so the more uh pollution you have the cooler the climate is and so now we're removing that pollution and so that's causing a little bit more warming on top
00:10:28
of the warming from the greenhouse gases and the and the deforestation and all okay let me I have to restate what you just said because people this is mind-blowing what you're saying is we are so good at stopping air pollution
00:10:41
that that is a factor in your models that is actually heating the air because previously the air pollution was blocking sunlight from hitting Earth's surface that's what you're saying that
00:10:55
is what that is what I'm saying hang on one second I gotta get my way Carol get me an aerosol can I got to start spray come on everybody do your so now you're going to send everybody out there to just do like I was going to say that
00:11:08
like Neil and I were the problem because we have hair and you don't and we're spraying and using dryers and stuff but it turns out that we're the ones fixing the we can't win so uh our ability to
00:11:21
keep track of all of these different things is actually pretty limited we're actually launching a satellite um in uh beginning febal Pace uh which for the first time will produce uh a map of the
00:11:35
composition of all of these different Aerosoles all these different particles in the atmosphere across the globe um and we're we're fingers crossed that goes well uh but uh but we have the possibility from then on uh to really uh
00:11:48
kind of nail down those uncertainties uh by by quite a lot so what you're hinting at here is in the future where geoengineering might be a thing um if we want to cool the Earth abruptly we could
00:12:01
reintroduce aerosols of a particular size into the atmosphere there are some real problems with that as a as a as a solution uh the main one is is that once you start and it's working you can't
00:12:14
stop like ever and uh and and when I say ever I mean like hundreds of years um and so uh because you're constantly fighting what
00:12:26
how tie the temperature would be and if you then if you stop then boom boom the temperature jumps just like it did this past year right much bigger you don't know how much to calibrate that to know
00:12:39
exact how yeah you see yes I know words these are exactly the issu so how would you calibrate it how would you govern it what happens when something goes wrong it's a non-starter for any actual
00:12:53
sustainable responsible solution okay so rather than leave The Listener thinking we're all you you please just give us some positive I was thinking the exact same thing before we close out okay the
00:13:06
good news is is this so if you take if you take these same models you take the same thing and you and you match everything uh if you suddenly stop making the problem worse if you suddenly stop adding carbon dioxide into the
00:13:20
atmosphere it basically stops right this the the global warming just stops things don't get any worse and that means means that anything that we do what we're
00:13:32
doing now we're in charge of what the future is so the future is determined by our actions we're not we're not uh we're not on a runaway train here uh we're not
00:13:45
out of control we have agency and we control what is going to happen in the future but we is not an accurate we in all seriousness because you got half the population that's fighting the other half that's trying to deal with it so
00:13:56
the Wii is not really an effective we okay so you know how how we get the we to all be collectively pushing in the same direction that's beyond my payr right should we be able to do that like
00:14:09
we as a society we control our future and uh that means that however however dire the news sounds we have the ability to make decisions to make it better to
00:14:23
make it stop uh and we can continue to make those decisions and and we have to continue to make those decisions and we're going to be making those decisions you know from now you know you know for the rest of this Century uh and we have
00:14:37
to make better decisions if this is going to slow down and stop and if not then the upside the global warming is uh turkeys will base in their own juices apples will bake on the trees and you'll
00:14:51
be able to grill right on George Foreman it'll be awesome so you got some upside there it's I mean it's doing wonders for uh for for p Noir in Oregon and Washington State Gavin I
00:15:04
understand that some fraction of the CO2 we put in the air gets absorbed into the ocean so that's in equilibrium so if we start dropping CO2 by whatever magic methods we have isn't it just going to come back out of the ocean and be no
00:15:18
better than we were before well the idea is to go back to what we were doing before but but yes I mean so so uh for every uh ton that we put into the atmosphere half of it get sequestered straight away and half of it is still in
00:15:30
the atmosphere and so when you take out uh a ton uh you have to take out a half from the atmosphere and a half from the ocean as well oh okay it goes both ways it's not quite symmetric but it's quite close to being symmet but I am right
00:15:44
that if you take the full ton back out of the air a half a ton comes back out of the ocean to fill the air again yes that's exactly okay so it's a CO2 echo system that we have to consider but if you take stuff out it's it it's it stays
00:15:57
out it doesn't but it's just not quite as effective as uh as you might have thought initially so Gavin thanks for responding to our distress signal because we were all very disturbed hearing that and uh thanks for scaring
00:16:08
the living out of it you're welcome it's uh it's my joke way to go all right Gavin Paul thanks for being there this has been another St talk explainer this one on climate and
00:16:23
climate change Neil grass Tyson your personal asro buiness it keep looking up [Music] a
End of transcript