Speaker 1: Welcome to zero. I am aksha darti. This week a
Speaker 1: climate science mystery. One year is out and a new
Speaker 1: year is here. And if you're observing the broad trends
Speaker 1: of climate change, that might be enough to worry you.
Speaker 1: The ten hottest years on record have all occurred in
Speaker 1: the past decade, and twenty twenty four isn't bucking the trend.
Speaker 1: In December, the European Union's Kupernikus unit said that when
Speaker 1: the final numbers are tallied, it is virtually certain that
Speaker 1: twenty twenty four will be the hottest year ever and
Speaker 1: for the first time, the global average temperature for the
Speaker 1: entire year is likely to go past the threshold of
Speaker 1: one point five degrees celsius above pre industrial levels. In
Speaker 1: his New Year's message, UN Secretary General Antonio Guteriz said,
Speaker 1: this is quote climate breakdown in real time. If you've
Speaker 1: been following this, it might be my numbing to hear
Speaker 1: scientists repeat hottest year, hottest year, hottest ear like a
Speaker 1: broken record year after year. But it's pretty significant if
Speaker 1: you go past one point five C and something worth
Speaker 1: unpacking because it's going to affect all of us. One
Speaker 1: point five C is the goal under the Paris Agreement
Speaker 1: that all governments agreed on. It's also resulted in corporations
Speaker 1: tying their net zero goals to the one point five
Speaker 1: sea target. So this week I wanted to speak with
Speaker 1: two Bloomberg Green reporters who have followed this closely, Eric
Speaker 1: Rosston in New York and Zarah Heirgee in Washington, d c.
Speaker 2: Oh.
Speaker 1: Eric, let's start with you, because you and I both
Speaker 1: know that this one point five c breach is important,
Speaker 1: and yet it is not quite the breach of the
Speaker 1: Paris Agreement, right.
Speaker 2: It is significant. There's been so much attention in recent
Speaker 2: years to the one point five degree goal, and there's
Speaker 2: also been increasing concern as global temperatures are approaching it.
Speaker 2: It's important to remember, though, that the Paris goal is
Speaker 2: understood to be an average like over twenty years. They're
Speaker 2: concerned about a one point five degree c temperature rise,
Speaker 2: and so this is not great, but technically it's not
Speaker 2: the ballgame.
Speaker 1: Still going about one point five degree celsius for the
Speaker 1: entire year is pretty dramatic, but there was also a
Speaker 1: build up towards it, with phenomena like al Ninio contributing
Speaker 1: to it. Do we know how much of the one
Speaker 1: point five ce was climate change and how much was
Speaker 1: other stuff.
Speaker 2: It's a great question, and I suppose the answer is no,
Speaker 2: which is what makes it a great question. Climate change
Speaker 2: is always adding more heat, and so when you get
Speaker 2: in al Nino and global weather is a little hotter
Speaker 2: than normal, you're more likely to get a record temperature,
Speaker 2: as we did in twenty twenty three and now in
Speaker 2: twenty twenty four as well. And consequently, when there's a
Speaker 2: La Nina, which is a cooling phase, you get the
Speaker 2: warming signal, but there's like a little speed bump, and
Speaker 2: so those years tend to be like the fifth hottest years. Ever,
Speaker 2: what's concerning this year has less to do with the
Speaker 2: actual final numbers one point five. It has to do
Speaker 2: with the fact that that simple rule of thumb climate
Speaker 2: change plus La Nina, climate change plus El Nino, it
Speaker 2: doesn't explain what's happening. And scientists can't explain with confidence
Speaker 2: yet why this year is so much hotter than it
Speaker 2: has been a past and what makes it a kind
Speaker 2: of who done it is? They've assembled some suspects, but
Speaker 2: they just can't say which one or which combination is
Speaker 2: responsible for the numbers. They're seeing from twenty twenty four.
Speaker 1: A scientific mystery. I'm all is up for one, but
Speaker 1: somehow when it comes to climate science, not really.
Speaker 2: Yeah, well, it's ominous because climate change is bad and
Speaker 2: we don't want more of it. But it's also concerning
Speaker 2: because notwithstanding the twenty twenty three and twenty twenty four records,
Speaker 2: scientists are afraid that it could signal an acceleration in warming.
Speaker 2: And if that's the case, we're not looking anymore at
Speaker 2: a couple of years that were in aberration. We're looking
Speaker 2: at a potential scenario that's worse than the pathway scientists
Speaker 2: had assumed we've been on.
Speaker 1: So acceleration, I mean, there was a period about ten
Speaker 1: years ago where people were talking about this quote unquote
Speaker 1: hiatus when warming had slowed down. Of course, that turned
Speaker 1: out to be spoonious data. Is there any worry that
Speaker 1: this acceleration might also be kind of spurious?
Speaker 2: A number of scientists have told me that what they're
Speaker 2: seeing now with these faster moving temperatures feels similar to
Speaker 2: that period of the hiatus ten or fifteen years ago
Speaker 2: that turned out to be sort of a data artifact,
Speaker 2: like temperatures just kind of started moving up again, and
Speaker 2: also there were important updates to the data itself that
Speaker 2: sort of corrected what turned out to be a kind
Speaker 2: of bias. I think scientists, a couple of them have
Speaker 2: told me that they're more concerned about this because they
Speaker 2: understand it better. All through that hiatus period, one of
Speaker 2: the things you heard was, well, we're not sure what
Speaker 2: it is, but really you can have like fifteen or
Speaker 2: twenty years of flatline temperatures and still not echo the
Speaker 2: prediction range for climate change. What's different now is that
Speaker 2: they have these suspects, and so there's there's a much
Speaker 2: stronger physical underpinning to the concerns, even though again they're
Speaker 2: just not sure what's causing the spikes.
Speaker 1: Okay, so who done it? Who are the suspects, and
Speaker 1: what do we know about them, and which ones are
Speaker 1: sort of the highly suspected and which ones we might
Speaker 1: want to drop out.
Speaker 2: So there is, as I said, there's climate change that
Speaker 2: makes things hotter. There is an al Nino through through
Speaker 2: the spring of twenty twenty four, and that made things hotter.
Speaker 2: The sun has entered the sort of increasing output of
Speaker 2: it of its eleven year cycle, and so that adds
Speaker 2: like a little bit of heat, but sort of a
Speaker 2: rounding error. The real culprit does have to do with
Speaker 2: these sulfur aerosols that humans put out. So nothing is
Speaker 2: clean in climate change, right, there's no free lunch. And
Speaker 2: so after you negotiation, the world's shipping industry a few
Speaker 2: years ago was able to make a path to reduce
Speaker 2: the sulfur content of the fuels they use. And that's
Speaker 2: great because that means less pollution.
Speaker 1: However, because this sulfur pollution causes air pollution, especially at ports,
Speaker 1: and that's really bad for humans. But there's a climate
Speaker 1: effect that comes from those sulfur particles too.
Speaker 2: Right, So that sulfur pollution is acid rain, right, and
Speaker 2: so that's what we wanted to get rid of in
Speaker 2: the West in the eighties and nineties. But there is
Speaker 2: this cooling effect. So all that shipping pollution actually had
Speaker 2: a little cooling effect. So when there was an eighty
Speaker 2: percent drop off in the sulfur pollution from shipping, there
Speaker 2: was no longer these chemicals to sort of reflect heat,
Speaker 2: and so it got a little warmer, particularly in the
Speaker 2: North Atlantic. Another thing that I think people just haven't
Speaker 2: talked about enough is a really monumental decline in these
Speaker 2: aerosol emissions from China. So between the shipping regulations and
Speaker 2: China and further progress in the US and Europe, we're
Speaker 2: seeing the disappearance of these cooling chemicals and that consequently
Speaker 2: is making things a little bit hotter.
Speaker 1: But is that a one time thing? Because like once
Speaker 1: the a results have disappeared and have led to this
Speaker 1: additional warming, will they continue to contribute to warming like
Speaker 1: carbon dioxide does, which is a greenhouse gas that keeps
Speaker 1: on absorbing the heat.
Speaker 2: It's a short term phenomenon, right, The atmosphere is catching up.
Speaker 2: There's conversations about whether we should spray the stratosphere with
Speaker 2: these chemicals on purpose in order to cool the atmosphere.
Speaker 1: Quote unquote geo engineering.
Speaker 2: Yeah, And one of the problems with that is if
Speaker 2: you ever stopped doing that, you'll get a heat spike
Speaker 2: like we're doing now. A big paper that made us
Speaker 2: splash and added a lot of explanation to what we've
Speaker 2: been seeing. Paper came out a month or two ago
Speaker 2: about how they ben like we're missing clouds. Low lying
Speaker 2: clouds do us a huge favor because they reflect a
Speaker 2: lot of sunlight, just sort of in the way that
Speaker 2: polar at ice caps do, and so the fact that
Speaker 2: we're starting to miss these low lying clouds, it's a
Speaker 2: real red flag for scientists because again, if that's just
Speaker 2: a blip and they come back, then we're on our
Speaker 2: warming trajectory we've been familiar with. But if that marks
Speaker 2: a change in the Earth's system itself, then we could
Speaker 2: be in line for more warming than we expected.
Speaker 1: And Zara, we talk about these temperature goals because well,
Speaker 1: they are goals and they are very important, but there
Speaker 1: are some real life implications off this level of warming,
Speaker 1: and particularly in twenty twenty three and twenty twenty four,
Speaker 1: we saw some of the most extreme weather events around
Speaker 1: the world. So beyond the fact that there is an
Speaker 1: arbitrary one point five seagull, why does it matter that
Speaker 1: we pay attention to these reports?
Speaker 3: So I guess there are a couple of reasons. First is,
Speaker 3: you know, when we think about one point five C
Speaker 3: as a goal and one point five C being broken
Speaker 3: in a particular year, I think something that all of
Speaker 3: us have heard when we've talked to scientists is like
Speaker 3: last year with sort of a preview and what a
Speaker 3: warmer world looks like. So when you have a full
Speaker 3: year where the temperature is basically above one point five CE.
Speaker 3: We saw the impacts of that in terms of extreme
Speaker 3: whether at least some of the impacts, and how destructive
Speaker 3: and uncomfortable it is. It's a reminder that we don't
Speaker 3: want to live in that all the time. I mean,
Speaker 3: when it's really hot, when we're getting devastating hurricanes, when
Speaker 3: we're getting brutal floods. That's not good. It kills people,
Speaker 3: it's bad for economy. I mean, it's it's not a
Speaker 3: great way to live, and it's a reminder of what
Speaker 3: is at stake in the long run as these impacts
Speaker 3: get worse. And so when we think about this goal
Speaker 3: and passing this goal, because that is the trajectory that
Speaker 3: we are on undeniably and something that's come out of
Speaker 3: my reporting, you know, this is what worth talking about,
Speaker 3: having to deal with more and more these kind of
Speaker 3: impacts all the time, and how disruptive they are.
Speaker 1: And the one point five C goal again is one
Speaker 1: that we talk about at cop meetings where there are all
Speaker 1: these countries coming together wanting to find new ways of
Speaker 1: addressing the challenge. But we also talk about it at
Speaker 1: corporate level because a lot of the net zero targets
Speaker 1: are tied to one point five C or a lot
Speaker 1: of the banks are trying to fund things so that
Speaker 1: they can keep temperatures below one point five C. How
Speaker 1: should they be thinking about perhaps changing their goals, finding
Speaker 1: new ways talking about a new goal, like what is
Speaker 1: it that they should think about if we have gone
Speaker 1: beyond one point five c?
Speaker 3: H One point five c as a goal is such
Speaker 3: a tricky thing, and there are so many like caught
Speaker 3: up emotions in it. I think a lot of scientists
Speaker 3: sort of hate it as a goal because in a
Speaker 3: way it feels rather arbitrary in the sense that there's
Speaker 3: nothing that is different at one point four to nine
Speaker 3: versus one point five versus one point five to one c.
Speaker 3: You know, those small increments. We can't actually tease out
Speaker 3: a lot of differences there, and so to them it's
Speaker 3: just we need to talk about trying to reduce or
Speaker 3: keep warming down as much as possible, and every tenth
Speaker 3: of degree matters. But obviously goals are important, and one
Speaker 3: point five C has been this rallying cry that we
Speaker 3: saw really truly drove momentum on climate action, and it
Speaker 3: is something that as you said, governments and companies can use.
Speaker 3: They like to have a number that they can push towards.
Speaker 3: You know, one of the things that I think about
Speaker 3: a lot that has been really important about one point
Speaker 3: five C is I was taught with Sam at the
Speaker 3: Gross from the Brookings Institution, and she was saying, you know,
Speaker 3: it wasn't that long ago that we were on a
Speaker 3: traructory of three C four C degree and now we're not.
Speaker 3: And that's sort of because we set on this goal
Speaker 3: and people really tried to reach it. But the thing is,
Speaker 3: the goal was always really ambitious and potentially always out
Speaker 3: of reach, and now we're sort of hitting up against
Speaker 3: that point when it's really becoming clear that we're not
Speaker 3: going to reach it. And so the question is does
Speaker 3: it lose its value as a goal, and do we
Speaker 3: need to have a new goal? But in the sense,
Speaker 3: you know, the thing that's tricky about this, and this
Speaker 3: is something that David Victor, who's a professor at the
Speaker 3: University of California at San Diego, told me, is right now,
Speaker 3: there's no context out there where groups can talk about
Speaker 3: things other than one point five SE and not be
Speaker 3: accused of backsliding. And I think there are people who
Speaker 3: would love to discuss a goal that's a little bit different,
Speaker 3: that seems a little bit more realistic, like a one
Speaker 3: point six or a one point seven or a one
Speaker 3: point seven to five, But at the end of the day,
Speaker 3: you still the actions that you're going to take to
Speaker 3: meet that goal versus one point five are pretty similar,
Speaker 3: and that you need to figure out how you're going
Speaker 3: to cut your emissions really fast, and companies and governments
Speaker 3: aren't doing enough of that, so it sort of doesn't
Speaker 3: matter what their goal is because they need to be
Speaker 3: doing more. And that's sort of the bottom line.
Speaker 1: After the break, more from my conversation with Zara and Eric.
Speaker 1: And by the way, if you've been enjoying this episode,
Speaker 1: please take a moment to rate and review the show
Speaker 1: on Apple Podcasts and Spotify. It helps other listeners find
Speaker 1: the show. This is a place where science and politics
Speaker 1: interacts in interesting ways. So the arbitrary nature of this goal, Eric,
Speaker 1: the fact that this is one point five C not
Speaker 1: one point six C, just give us a history. Why
Speaker 1: is it that we have these goals one point five
Speaker 1: C and two C.
Speaker 2: Well, while you're right, while it started out arbitrary, it's
Speaker 2: become less arbitrary. And that's because the UN diplomatic body
Speaker 2: that hosts the All nations to talk about climate change
Speaker 2: every year, they asked the Intergovernmental Panel on Climate Change
Speaker 2: very specifically in Paris when they were doing the Paris Agreement,
Speaker 2: to really study and understand the difference between one point
Speaker 2: five C and two degrees C, and that led to
Speaker 2: a super influential report in twenty eighteen that really for
Speaker 2: the first time puts specificity into what one point five
Speaker 2: I've seen means versus two degree cee versus one degree C,
Speaker 2: which is now in the rear view window. So it's
Speaker 2: somewhere between arbitrary and it's not a threshold, as Zara said,
Speaker 2: you know, it's not a threshold. It's not a cliff.
Speaker 2: But every ton of CO two that we put up
Speaker 2: in the air matters.
Speaker 1: But we are also living in twenty twenty five, sort
Speaker 1: of a year after all these elections that happen around
Speaker 1: the world, and we are seeing many parts of the world,
Speaker 1: including where you live Zara in the US, put in
Speaker 1: leaders who are likely to be very hostile to climate policy.
Speaker 1: So at the exact time that we are in the
Speaker 1: hottest year reaching one point five CE we're also getting
Speaker 1: politicians who are unlikely to be doing much on climate.
Speaker 1: How should people make sense of this moment?
Speaker 3: I'm still trying to make sense of this moment. I mean,
Speaker 3: I think it's awkward, but it really gets at something
Speaker 3: we've seen over and over again when it comes to
Speaker 3: climate politics, and it's really sort of coming to a head,
Speaker 3: which is that bringing down emissions and dealing with the
Speaker 3: climate crisis is hard, it costs money, and it's scary.
Speaker 3: I do think it's important to remember that the last
Speaker 3: time that Donald Trump was elected president in the US,
Speaker 3: there were some surprising outcomes that sort of led to
Speaker 3: the we are all in coalition and kind of a
Speaker 3: bumping up of the one point five c rallying cry
Speaker 3: and people sort of pushing back on that, and so
Speaker 3: there's always sort of this push and pull. But what's
Speaker 3: hard about this is there is you know, you can
Speaker 3: have climate action from the bottom up and the top down,
Speaker 3: and I think we've seen that the most effective action
Speaker 3: really involves that top down. And when you're not having
Speaker 3: countries setting new regulations like that's going to push back progress.
Speaker 3: And so people recognizing that as much as you have
Speaker 3: politicians talking and downplaying these issues. They're not going to
Speaker 3: go away with the type of policies that they're advocating,
Speaker 3: and they're just pushing down the road the problems that
Speaker 3: are going to grow and arise out of this.
Speaker 1: Eric, you talked about the twenty eighteen report where scientists
Speaker 1: sort of work through what one point five C means.
Speaker 1: And in some way, scientists are very good at doing that.
Speaker 1: If you give them a goal, they'll tell you what
Speaker 1: is needed to meet it. So is one point five
Speaker 1: SE still possible even though technically everybody says we are
Speaker 1: going to preach it.
Speaker 2: Yeah, So scientists started talking about overshoot when they realized
Speaker 2: we may not stay within our carbon budget and temperatures
Speaker 2: may rise beyond one point five sea or even higher temperatures,
Speaker 2: And it became a word that's it's sort of an
Speaker 2: impetus to find ways to correct the problem that we've
Speaker 2: now created.
Speaker 1: And so these are technologies like director capture, which will
Speaker 1: remove carbon dioxide from the air. What else is there
Speaker 1: this list of dealing with overshoot?
Speaker 2: The biggest tool in our toolbox, though, is not polluting more.
Speaker 2: You know, we're still putting up more than one hundred
Speaker 2: million tons of co two a day from fossil fuel
Speaker 2: and cement making, and that is the main thing we
Speaker 2: need to do to prevent overshoot. You can't address overshoot
Speaker 2: until you stop making the problem worse.
Speaker 1: If we do eventually get serious about these goals and
Speaker 1: you know, want to still stay beyond one point five,
Speaker 1: see overshoot might be an option. But if the politics
Speaker 1: is hard right now, how much harder is it going
Speaker 1: to be when you're trying to convince people you have
Speaker 1: to do all these weird wacco things that are going
Speaker 1: to be necessary in a world of overshoot.
Speaker 3: I mean, I think the assumption is that overshoot is
Speaker 3: already on the table. When a lot of people are
Speaker 3: talking about one point five still being alive, they're actually
Speaker 3: the unspoken part is they are assuming or banking on overshoot,
Speaker 3: this idea that we are going to go above one
Speaker 3: point five and then have the tools necessary to eventually
Speaker 3: bring it down. The concern about focusing too much on
Speaker 3: overshoot is that then we sort of lose sight of
Speaker 3: the fact that we need to bring emissions down, not
Speaker 3: just invest in the technologies that can help pull it
Speaker 3: out of the air and rely on that or overly
Speaker 3: rely on that because we don't know a lot about
Speaker 3: how that will work. And so I feel like the
Speaker 3: answer is we have to do both. That's not actually
Speaker 3: a pitch you have to make to people. I think
Speaker 3: that's just where we are today, and you're sort of
Speaker 3: starting to see it with the policies that came underway
Speaker 3: with the Biden administration and how actually a lot of
Speaker 3: the companies and industries that are going to need or
Speaker 3: rely on overshoot are the ones getting text credits and
Speaker 3: sort of investing on it. And the problem is you
Speaker 3: don't want them to overinvest on that versus not actually
Speaker 3: changing anything to their business. But I think we actually
Speaker 3: need to talk about it it more as something that
Speaker 3: is on the table now and just dig into a
Speaker 3: little bit more about what that looks like. But I
Speaker 3: don't think it's a matter of if or when, Like
Speaker 3: we're here and we're dealing with it, and it's just
Speaker 3: maybe changing what that means and what we need to
Speaker 3: do about it.
Speaker 1: Well, climate change one point five and twenty twenty five,
Speaker 1: it's going to be a messier. Thank you both for
Speaker 1: at least setting the stage for what is going to
Speaker 1: be a messier and we'll talk a lot more about it.
Speaker 1: Thank you, thank you, thank you for listening to Zero.
Speaker 1: And now for the sound of the week, which I
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