Latest / The Smart Cookies podcast / Are We Losing the Climate Change Fight? With Prof. Michael Mann

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Are We Losing the Climate Change Fight? With Prof. Michael Mann · The Smart Cookies podcast

• 0:00
  ...that was being blown in from raging wildfires
• 0:04
  in Canada, which too are now an annual occurrence.
• 0:08
  That didn't used to happen. And the air quality
• 0:11
  in Philadelphia in the summer didn't used to
• 0:14
  be the worst in the world at times, but it is
• 0:16
  now. And that has real health consequences. So
• 0:20
  whether it was the dangerous air we were breathing
• 0:22
  here in the eastern U .S., in the largest cities
• 0:26
  of the eastern U .S., or the fires that are raging
• 0:30
  in Europe right now, floods elsewhere, tornado
• 0:33
  outbreaks, dangerous climate change is here.
• 0:36
  And the question is, how bad are we willing to
• 0:39
  let it get? Ladies and gentlemen, it's an unbelievable
• 0:46
  privilege to be able to introduce this episode's
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  guest, a Presidential Distinguished Professor
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  of Earth and Environmental Science and Director
• 0:53
  of the Penn Center for Science, Sustainability
• 0:55
  and the Media at the University of Pennsylvania,
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  Professor Michael Mann. Welcome to the program.
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  Thanks. It's great to be with you. You might
• 1:02
  be one of the most renowned climate scientists
• 1:04
  in the world, but as a film buff myself. I would
• 1:08
  be remiss not to add that you also have one of
• 1:11
  the best short bios on social media out there.
• 1:13
  It says, I didn't direct heat. I predicted it.
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  Credit where credit is due, Professor. What a
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  line. Thank you. Yeah, well, you know, because
• 1:21
  there was so much confusion between me and the
• 1:24
  other Michael Mann, I figured I had to come up
• 1:26
  with some short, punchy... explanation of the
• 1:31
  difference between the two of us. So there you
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  are. You certainly did it. Okay. Now that we've
• 1:35
  gotten the important stuff out of the way, there's
• 1:37
  been a lot of really anxious talk, especially
• 1:40
  on social media of an upcoming super El Nino.
• 1:44
  Some folks are even referring to it as a Godzilla
• 1:47
  El Nino. Can you tell me what this phenomenon
• 1:51
  is and why are people super scared about the
• 1:55
  upcoming one? Yeah, and I've got to admit, I
• 1:57
  was a bit of a skeptic early on when people were,
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  you know, there's sometimes a tendency to hype
• 2:03
  things just sort of for clicks and page views
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  and, you know, especially in the online world
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  and social media. And so it felt like, you know,
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  this was happening early on with this El Nino.
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  But as time has gone on. And as the forecasts
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  have shaped up, there's something called the
• 2:20
  predictability barrier, the spring predictability
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  barrier, which is just historically, it's very
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  difficult to predict what is going to happen
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  with El Nino before you go through the northern
• 2:31
  hemisphere spring. Once you're into June, it
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  really starts to take shape. And so there were
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  early prognostications of a Godzilla El Nino
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  back in March and April before we were through
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  that barrier. And I was skeptical because there
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  was so much. spread among the models. There were
• 2:48
  a few models that were way out there and people
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  were pointing them, but there were other models
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  going in the other direction. Now that we're
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  through that spring predictability barrier and
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  the forecasts have started to sort of cluster.
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  more. We are almost certainly headed towards
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  an historic El Nino, an El Nino that at least
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  by some measures will be the largest El Nino
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  on record. We know that El Nino has profound
• 3:15
  consequences for weather patterns around the
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  world. It changes the behavior of the jet stream.
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  Some places are much hotter than usual. Some
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  places actually are cooler than usual. Some much
• 3:27
  wetter, some much drier. During El Nino years,
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  You tend to have wet conditions in the winter
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  along the west coast of the U .S. You tend to
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  have fairly quiet Atlantic hurricane seasons.
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  But in the Pacific, you have a more active hurricane
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  season. And so there are a lot of things that
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  El Nino does. And a really big El Nino is going
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  to have bigger consequences. El Nino also raises
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  the average temperature of the planet. Now, that's
• 3:54
  a temporary factor by a few tenths of a degree
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  Celsius. Now that we're watching the ongoing
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  warming of the planet, every time we get a big
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  El Nino event, it pushes us to a new threshold
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  that we've never seen before. And that threshold
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  can lead to all sorts of extreme weather behavior.
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  And so there is a lot of apprehension. about
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  what we're going to see as this El Nino continues
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  to take form. It's called El Nino because it
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  typically sort of crystallizes, it maximizes,
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  it reaches its peak during the northern hemisphere
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  winter around Christmas time. And the South Americans
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  who first observed this phenomenon called it
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  El Nino after the Christ child because it would
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  typically arrive around Christmas time. And that's
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  when we expect to see this episode peak. And
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  by all accounts, it's going to be a whopper of
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  an El Nino. It's another experiment that our
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  global climate is performing for us. We're going
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  to learn a whole lot from it. But it's also going
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  to provide us a glimpse of what the future may
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  look like if we continue with this steadier warming
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  of the planet. El Nino will go away. It'll subside.
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  And the warming impact of it will be gone in
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  a year or so. But the steady warming... due to
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  increasing carbon pollution, that will be there.
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  But what is an El Nino? And if you would be so
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  kind as to explain it as if I'm 10 years old,
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  because that's how I feel. No, I was remiss in
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  not actually even talking about what it is. So
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  it's sort of the weather of the climate system.
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  You know, weather is something that happens from
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  day to day. It's just the random, chaotic. variability
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  of the atmosphere. And even if we weren't doing
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  anything to the planet, it would happen because
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  there's just natural variability that happens.
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  It's chaos. It's just part of the intrinsic characteristics
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  of our atmosphere that you get this sort of three
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  to seven day weather cycle with warm fronts and
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  cold fronts and mid -latitude cyclones. El Nino,
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  if you like, is sort of the weather. of the global
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  climate, which is to say it's also random internal
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  variability, just like weather is, but it has
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  a longer time scale because it doesn't just involve
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  the atmosphere, involves the ocean. And the ocean
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  sort of tends to behave more sluggishly. The
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  wave disturbances in the jet stream, those wiggles
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  in the jet stream that we see every day, those
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  wiggles sort of travel around the planet in a
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  week. quite quickly. There are other wave disturbances
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  in the tropical Pacific Ocean, and they're called
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  Kelvin waves. There are also Rossby waves, which
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  are like the jet stream waves, but they're in
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  the ocean. So there are these other wave disturbances
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  in the ocean, and they're much slower. They take
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  months or the better part of a year, for example,
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  to cross the Pacific Ocean. And so what happens
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  is you get these wave disturbances in the ocean.
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  Now, these aren't the sorts of waves that you
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  can surf. You don't see them at the surface.
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  They're happening beneath the surface, but they're
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  changing the amount of heat that is delivered
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  from the deep ocean to the surface. In the case
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  of El Nino, what happens is that the trade winds
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  stop blowing in the eastern... Tropical Pacific.
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  The trade winds at the equator drive what we
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  call upwelling. They bring cold water to the
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  surface. When those trade winds stop blowing,
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  you stop bringing that cold water to the surface.
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  If you've ever tried swimming in the Galapagos
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  Islands, it's typically really cold. You're right
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  at the equator, but it's cold because you've
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  got deep water upwelling coming to the surface.
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  Equatorial upwelling, we call it. Well, when
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  the trade winds relax, and that can do to some
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  you know random burst of winds in the tropical
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  pacific the the trade winds break down you stop
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  the upwelling so you stop the delivery of the
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  cold water to the surface and the eastern equatorial
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  pacific warms up tremendously and if you look
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  at a map right now of global temperature anomalies
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  the departures from normal you'll see a huge
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  bullseye in the eastern and central uh equatorial
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  and tropical Pacific because we've cut off that
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  source of cold water. The ocean surface has warmed
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  up there. And when the ocean surface warms up,
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  it heats the atmosphere and it causes it to rise.
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  And it causes a change in the overall circulation
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  of the atmosphere itself. And that change in
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  the atmospheric circulation feeds back on those
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  trade winds, which drove the... change and upwelling
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  in the first place. So we call it a coupled phenomenon
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  because you can't understand it purely in terms
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  of the ocean or in terms of the atmosphere. We
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  can only understand it in terms of the push and
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  pull of the ocean and atmosphere, the tropical
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  Pacific ocean and atmosphere working together.
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  And that push and pull is the weather of the
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  climate, if you like. It drives this just sloshing.
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  of heat and changes and wind patterns that have
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  a global consequence. It's a natural phenomenon.
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  It's been around as near as we can tell for many,
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  many thousands of years. Climate change, human
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  -caused climate change, may be changing the behavior
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  of El Niño. That is very uncertain. Scientists
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  don't agree on how El Niño might be changing
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  and whether this huge El Niño event might be
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  heralding. a change in the character of El Nino,
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  bigger El Nino events as we warm up the planet.
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  There's some evidence that we might expect the
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  opposite. And this is a real debate. We hear
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  too many fake debates about whether climate change
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  is real, whether it's caused by human activity.
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  This is a real debate. Scientists really don't
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  know the answer yet to how El Nino will change
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  in the future. It's an uncertainty. But as we've
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  learned, Many of these uncertainties aren't our
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  friend. As we learn more, as things play out,
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  we often find that the changes happen even sooner
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  than we expected. And maybe there are some unwelcome
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  surprises in store when it comes to how climate
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  change is impacting this huge phenomenon of El
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  Nino. You mentioned these clickbaity social media
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  posts, and they usually reference or they say
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  that the damages from the last super El Nino
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  run into the... billions or even trillions of
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  dollars, which regions are going to get the worst
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  of it? Yeah, so it's actually pretty complicated.
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  As I alluded to before, El Nino years tend to
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  be relatively quiet hurricane seasons, the Atlantic.
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  From the standpoint of hurricane damage, we would
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  expect less of that typically during a strong
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  El Nino year. La Nina, which is the opposite.
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  It's when the tropical Pacific is really cold,
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  much colder than normal. It's the flip side of
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  El Nino. That actually leads to worse drought
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  in the western U .S., in the southwestern U .S.,
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  so it's bad from the standpoint of water resources
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  in the western U .S., and it leads to more active
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  hurricane seasons. But in other places, El Nino
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  causes more active. hurricane activity. As we
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  said, in the Pacific, for example, in the Eastern
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  Pacific, we see more hurricane activity typically
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  during an El Nino year. So it really depends
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  on where you are. Now, it does elevate the overall
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  average temperature of the planet. And that does
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  drive overall an increase in intensity of what
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  we call the water cycle and storminess. And so
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  On the whole, El Nino probably is more disruptive
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  than the flip side, which is La Nina. And it's
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  pushing us more towards that warmer planet, at
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  least temporarily. And we know there are all
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  these negative consequences of a warmer planet.
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  So overall, it's probably not. It's an aggravating
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  effect on top of human caused warming. But the
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  precise impact depends very much on where you
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  are. We tend to see warmer winters. in the northern
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  half of the U .S. during an El Nino winter. Now,
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  some people like warmer winters. They might say,
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  oh, that's a good thing, but that can be disruptive,
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  and there are changes in rainfall patterns, and
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  even tornadoes shift in sort of the location
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  of maximum tornado activity. in, you know, the
• 13:04
  eastern US, a shift more towards, you know, away
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  from Tornado Alley towards sort of Florida and
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  the east coast during El Nino years. So there's
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  a lot of sort of... Yeah, excuse me. What about
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  Europe, where most of my listeners are located?
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  Yeah, so here's the good news. Europe is far
• 13:24
  enough afield... from the tropical Pacific that
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  it doesn't feel those so -called teleconnections
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  as strongly as North America. What happens is
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  the heating in the tropical Pacific generates
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  sort of a perturbation in the jet stream that's
• 13:39
  really strong over the North Pacific and pretty
• 13:43
  strong over North America, but it sort of dampens
• 13:46
  out by the time you get all the way over to Europe.
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  And so Europe typically doesn't see any reliable
• 13:53
  or consistent impact of El Nino. But the planet
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  overall is warmer, and that has consequences
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  for weather around the planet on average. Professor,
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  in 2024, you released your book, Our Fragile
• 14:08
  Moment. And during that time, you gave an interview
• 14:11
  for The Guardian during which you said, we're
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  not doomed yet. Two and a half years later, has
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  your prediction changed at all? Yeah, we're doomed.
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  Sorry. That was quick. It happened a year ago.
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  I believe you. We crossed the threshold. Well,
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  you know, if we're doomed, it may be for other
• 14:33
  reasons. It may be because of the fraught nature
• 14:35
  of our politics here in the U .S. That was my
• 14:39
  most recent book, Science Under Siege, with Peter
• 14:42
  Hotez. It's really about the assault on... Public
• 14:46
  health science on climate science under the current
• 14:49
  administration, under the Trump administration
• 14:51
  and congressional Republican control of our Congress.
• 14:57
  And the rise of disinformation, anti -science
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  disinformation that's promoted by bad actors,
• 15:08
  the fossil fuel industry, conservative interest
• 15:12
  groups, that makes it so difficult. for us to
• 15:15
  take the actions necessary to deal with the climate
• 15:19
  crisis, to deal with ever more dangerous and
• 15:22
  deadly pandemics. And so if we're doomed, it's
• 15:27
  likely going to be for other reasons. It's going
• 15:31
  to be for the fraught nature of politics. And
• 15:33
  there I have hope, right? Because political will
• 15:38
  is renewable. The laws of physics are immutable.
• 15:42
  If the laws of physics told us it was too late,
• 15:45
  to stabilize the planet's climate below catastrophic
• 15:50
  levels of warming. I would tell you that. If
• 15:54
  that's what the science told me, if that's what
• 15:55
  the physics said, I would tell you that. But
• 15:58
  it doesn't. The laws of physics are immutable,
• 16:02
  but the laws of politics are not. And so it's
• 16:05
  still up to us. We're still at the point where
• 16:08
  if we take the right actions, we can prevent
• 16:11
  truly catastrophic... You know, global climate
• 16:16
  impacts. We're already seeing, you know, in places
• 16:20
  dangerous, damaging and deadly. We're not going
• 16:23
  to escape that because it's already here. The
• 16:26
  question is, can we sort of keep the impacts
• 16:28
  within our, you know, our adaptive capacity,
• 16:32
  our ability to to, you know. adapt to those changes
• 16:38
  that are inevitable, instill measures that will
• 16:42
  put in place measures that will instill resilience.
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  At some point, we leave that sort of range of
• 16:49
  adaptive capacity, but we're not there yet. And
• 16:53
  so what we need to do. is stop burning fossil
• 16:56
  fuels, move away from fossil fuel energy to clean
• 17:00
  energy, decarbonize our societal infrastructure
• 17:03
  as quickly as possible so we don't make all of
• 17:06
  this worse while investing in the adaptation
• 17:12
  that's going to be necessary just for us to deal
• 17:15
  with those changes that are now baked in. All
• 17:18
  right, that was much more hopeful than I was
• 17:20
  expecting because... Reading the headlines is
• 17:25
  a bit daunting lately. I read a startling article
• 17:27
  in Science Alert yesterday. The title reads,
• 17:30
  scientists detect a sharp acceleration in global
• 17:33
  warming. Let me read just two lines from it.
• 17:36
  The adjusted data show an acceleration in global
• 17:38
  warming since 2015 with a statistical certainty
• 17:40
  over 98%, explains Stefan Ramstorf from the Potsdam
• 17:46
  Institute for Climate Research. The article goes
• 17:48
  on to say that we'll probably breach the 1 .5
• 17:51
  Celsius degrees we set up for our... for ourselves
• 17:53
  in the Paris Agreement. That sounds scary. What
• 17:57
  are your thoughts? Yeah, so Stefan is a good
• 18:01
  friend of mine. We've worked together on a whole
• 18:03
  range of problems over the years, including a
• 18:06
  paper back in 2015, where we showed that the
• 18:09
  so -called ocean conveyor, the Great Ocean Conveyor
• 18:13
  sort of... that popularized in the movie The
• 18:16
  Day After Tomorrow that sort of delivers heat
• 18:19
  to the higher latitudes of the North Atlantic
• 18:22
  and warms Europe. The AMOC. The AMOC, exactly.
• 18:25
  The Atlantic Meridional Overturning Circulation.
• 18:28
  That just rolls off the tongue, doesn't it? So
• 18:30
  I like the conveyor. But yes, the AMOC is slowing
• 18:34
  down. And we actually showed back in 2015 in
• 18:37
  an article in Nature Climate Change that that
• 18:40
  was happening ahead of time. That's an example
• 18:43
  of one of those changes. You know, uncertainty
• 18:44
  isn't our friend. It's happening and it appears
• 18:47
  to be happening earlier than we expected. On
• 18:50
  this particular matter, I part ways with Stefan.
• 18:54
  Now, that press release, it was a little weird
• 18:56
  to me because it was a reissued press release
• 18:59
  on an article they published almost a year ago.
• 19:02
  They just decided to put it out again. on Science
• 19:06
  Daily or whatever the website was. So it looks
• 19:10
  like they put out the press release. And sometimes
• 19:11
  institutions do that. They see a news cycle that
• 19:14
  might be favorable for a story that didn't get
• 19:18
  as much traction when they first put it out.
• 19:21
  And right now, this is a pretty ripe environment
• 19:23
  for talking about the climate crisis. So it looks
• 19:27
  like they put it back out there. But it's actually
• 19:29
  old. There's not a new article. they published.
• 19:32
  We published an article actually since then in
• 19:35
  the Proceedings of the National Academy of Sciences,
• 19:37
  where we showed that the recent temperatures,
• 19:41
  including the record global temperature 2024,
• 19:44
  was consistent with the models. The truth is
• 19:47
  bad enough. The models predict steady warming
• 19:50
  as long as we continue to add carbon pollution
• 19:53
  to the atmosphere. And there are fluctuations
• 19:55
  around that due to things like El Nino. 2023
• 19:58
  -24 was one of those very large El Nino events.
• 20:02
  And so there was a positive fluctuation. But
• 20:04
  what we showed was what we saw, what we see in
• 20:08
  the temperature record is consistent with the
• 20:10
  model predictions of steady warming plus the
• 20:12
  random effect of El Nino. So the truth is bad
• 20:17
  enough. No, we're not. There's no evidence, for
• 20:20
  example, in our article shows there's no evidence
• 20:22
  that we are seeing. some acceleration of warming
• 20:25
  that isn't predicted by the models. Now, there
• 20:28
  was an acceleration of warming when we passed
• 20:30
  the Clean Air Acts back in the 1970s that, you
• 20:35
  know, we had been producing, you know, coal -fired
• 20:37
  power plants had produced all of the sulfur pollution
• 20:40
  that was blocking out sunlight and actually cooling
• 20:43
  off the planet. But that sulfur pollution was
• 20:45
  also acidifying lakes and rivers in Europe and
• 20:49
  North America. And so we passed the Clean Air
• 20:51
  Acts. That... One of the consequences of that
• 20:56
  is that unmasked warming that had been hidden
• 20:58
  by the sulfur pollution. So you see, with the
• 21:01
  passage of the Clean Air Acts, an acceleration
• 21:04
  of warming in the late 1970s. And it sort of
• 21:08
  puts us on a more rapidly warming trajectory.
• 21:13
  But there's no evidence that, A, there's anything
• 21:17
  there that isn't captured in the climate models
• 21:20
  that we use. to predict the future. And that's
• 21:23
  true of the last decade. The trend over the last
• 21:26
  decade is consistent with the climate models.
• 21:28
  And what those models tell us a little bit of
• 21:30
  good news, getting back to your question about,
• 21:32
  you know, hopefulness, doom, what have you. One
• 21:35
  thing we've learned with much greater confidence
• 21:37
  over the last 10 to 15 years We used to think
• 21:41
  that the planet would continue to warm up even
• 21:44
  after we stopped burning fossil fuels because
• 21:46
  of the so -called thermal inertia of the oceans,
• 21:50
  the sluggishness of the oceans. They continue
• 21:52
  to warm up. And that's true, but there's an offsetting
• 21:56
  factor which wasn't included in the early simulations
• 21:59
  and is much better captured in more comprehensive
• 22:02
  models run today where the oceans and the vegetation
• 22:06
  on the Earth's surface are taking carbon out
• 22:09
  of the atmosphere. So when we stop putting carbon
• 22:13
  pollution into the atmosphere, the CO2 levels
• 22:15
  start to come down. The greenhouse effect actually
• 22:18
  slightly cools. It starts to cool. That offsets
• 22:22
  the warming, the extra warming that we would
• 22:25
  expect from that thermal inertia. Those two things
• 22:28
  basically cancel out and you get a flat line,
• 22:31
  which is to say when carbon emissions reach zero,
• 22:34
  the surface temperature of the planet stops warming
• 22:38
  almost immediately. And that is now very much
• 22:41
  the consensus of the world's climate scientists.
• 22:44
  It hasn't gotten out there. That understanding
• 22:47
  hasn't penetrated into our public discourse as
• 22:51
  much as I would hope. It's actually the basis
• 22:53
  for the whole notion of a carbon budget. The
• 22:57
  reason we can talk about a carbon budget is that
• 22:59
  there is some amount of carbon that we can afford
• 23:02
  to burn and keep global temperatures below some
• 23:05
  level. like 1 .5 Celsius. Stefan might be right
• 23:10
  about that. We're very close to burning through
• 23:12
  the carbon budget for 1 .5 Celsius. On that,
• 23:16
  I agree. But that's not the end of the world.
• 23:20
  We still go for 1 .6. If we miss 1 .6, we still
• 23:23
  go for 1 .7 because every fraction of a degree
• 23:26
  means much less harm and damage done. You said
• 23:30
  we need to stop emitting as soon as possible,
• 23:33
  but it doesn't look like that's going to be the
• 23:35
  case. And if we keep going at it like we are
• 23:39
  right now, what is the world going to look like,
• 23:41
  let's say, in 10 or 20 years on our current trajectory?
• 23:46
  Yeah, so there's been a whole debate about this
• 23:48
  a few months ago. The latest IPCC assessment.
• 23:55
  sort of published a new set of scenarios, the
• 23:58
  so -called CMIP7s. Basically, the scenarios are
• 24:02
  like different possible pathways that we can
• 24:05
  envision of future carbon emissions under different,
• 24:09
  you know, policies, under different global international
• 24:14
  climate policy and domestic energy and climate
• 24:18
  policies. there was a little bit of, again, a
• 24:25
  little bit of good news. The worst case scenario
• 24:27
  isn't quite as bad as it once looked. The so
• 24:30
  -called business as usual, like if we don't make
• 24:33
  any further progress, we just go with the policies
• 24:35
  we have today. We've made enough policy progress.
• 24:39
  For example, this year, 86 % of all added global
• 24:45
  power generation capacity will be renewable energy.
• 24:49
  So we are decarbonized. We're moving away from
• 24:51
  fossil fuels. We're moving towards clean energy,
• 24:54
  not as fast as we'd like to see, but we are moving
• 24:57
  in that direction. And so business as usual doesn't
• 25:00
  look as bad as it once looked. Current policies
• 25:04
  alone don't look as bad as they once looked.
• 25:07
  They used to look like four degrees Celsius,
• 25:10
  seven degrees Fahrenheit warming later this century.
• 25:14
  Now it's more like. three degrees Celsius, a
• 25:18
  little more than three Celsius. That's still,
• 25:20
  yes. And you're right to grimace because that's
• 25:23
  still really bad. Professor, right now we're
• 25:25
  at 1 .3 over, right? Added warming, 1 .3 Celsius.
• 25:30
  And three would be really bad. I'm glad that
• 25:35
  you grimaced on that because we have to be able
• 25:37
  to, there are these two seemingly conflicting
• 25:40
  things we have to hold in our minds at the same
• 25:42
  time. We've made progress. It isn't nearly. Enough
• 25:47
  progress. I just wanted to say that at 1 .5 or
• 25:50
  nearly 1 .5 where we're at right now, half of
• 25:53
  Europe is burning every summer. And the headlines
• 25:56
  keep getting scarier and scarier. Part of it
• 25:59
  might be clickbaity stuff, like you said at the
• 26:01
  beginning. But some of it is real. You know,
• 26:04
  I come from a small country called Slovenia,
• 26:08
  Southeast Europe. And the weather has changed
• 26:12
  profoundly since when I was a kid. No question.
• 26:16
  And not for the better, if I might add. We're
• 26:19
  having like crazy floods. We're having like wildfires.
• 26:23
  And none of this stuff was happening when I was
• 26:26
  a child. So I'm just imagining if that's happening
• 26:29
  in 1 .5, what does it look like at 3? That's
• 26:35
  exactly right. I mean, this is one of the things
• 26:37
  that I've been trying to drive home in terms
• 26:40
  of my own messaging. Dangerous climate change
• 26:43
  is here. It's not a... It's not at 1 .5, 2 or
• 26:48
  3. It's here. Look out your window. Dangerous,
• 26:52
  damaging, deadly climate change is here. And
• 26:55
  my good friend Stefan Ramstorf, again, I mentioned
• 26:58
  earlier, there was an article that appeared in
• 27:01
  one of the Murdoch papers, the Telegraph in the
• 27:05
  UK, you know, mocking concern about climate change,
• 27:10
  saying England just has to welcome its Mediterranean
• 27:13
  future. As the Mediterranean is on fire, and
• 27:17
  Stéphane sort of mockingly posted a photo, here's
• 27:21
  my Mediterranean vacation for you. And he came
• 27:25
  face to face with those wildfires. He and his
• 27:27
  family came face to face with those wildfires
• 27:29
  in southwestern France. So you're absolutely
• 27:33
  right. We are seeing catastrophic climate impacts
• 27:36
  now in Europe, here in North America, where...
• 27:41
  You know, my city of Philadelphia, we had unhealthy
• 27:43
  air, not because of smog, but because of Canadian
• 27:48
  wildfire smoke that was being blown in from raging
• 27:53
  wildfires in Canada, which too are now an annual
• 27:57
  occurrence. That didn't used to happen. And the
• 28:00
  air quality in Philadelphia in the summer didn't
• 28:04
  used to be the worst in the world at times, but
• 28:06
  it is now. And that has real health consequences.
• 28:09
  So whether it was the dangerous air we were breathing
• 28:13
  here in the eastern U .S., in the largest cities
• 28:16
  of the eastern U .S., or the fires that are raging
• 28:20
  in Europe right now, floods elsewhere, tornado
• 28:23
  outbreaks, dangerous climate change is here.
• 28:26
  And the question is, how bad are we willing to
• 28:29
  let it get? Let's talk about another highly unpleasant
• 28:32
  phenomenon, and that's data centers springing
• 28:35
  up everywhere, adding. to the emissions, I believe,
• 28:38
  guzzling up all the available water and causing
• 28:41
  all kinds of nasty pollution in those areas.
• 28:44
  How much do they set us back in terms of our,
• 28:46
  as you mentioned, carbon budget? Yeah, you know,
• 28:50
  they have the potential to set us back far more
• 28:53
  than they do now. So I think it's one of those
• 28:55
  things where, depending on how you extrapolate
• 28:57
  the trajectory, it potentially looks really bad.
• 29:00
  Right now, It's still a small, a pretty small
• 29:03
  fraction of total carbon emissions down in the
• 29:06
  low single digits. But we could imagine that
• 29:09
  scaling up given the plans that big tech has
• 29:13
  for scaling up data centers. Now, some of my
• 29:15
  colleagues will say there's some potential mitigating
• 29:19
  factors. For example, if you look at China, China
• 29:22
  has developed far more efficient AI algorithms
• 29:25
  that aren't nearly as power hungry. And so maybe
• 29:28
  that paves the way to far more efficient AI.
• 29:31
  I'm worried about sort of the direction that
• 29:36
  AI and machine learning are taking for a completely
• 29:38
  different reason, which is the way that AI is
• 29:41
  now being used to promote misinformation and
• 29:49
  disinformation at a massive scale. inundating
• 29:53
  us with misinformation and not random. I don't
• 29:57
  call it misinformation. I actually call it disinformation,
• 30:00
  climate denialism, attacks on renewable energy.
• 30:05
  Now we're dealing with fake videos and fake images.
• 30:13
  you can no longer trust what you see and hear
• 30:17
  yourself. And that's very dangerous. That's very
• 30:19
  dangerous when the machinery is being weaponized
• 30:23
  by the very bad actors that we're talking about,
• 30:26
  fossil fuel interests, polluters, plutocrats
• 30:29
  who want to gain the system for their advantage
• 30:33
  against our own interests, against the interests
• 30:35
  of us and the planet. And they have this tremendous
• 30:38
  machinery now with which to do it. And so that
• 30:41
  is my main worry. about AI and big data right
• 30:45
  now is the way it's being weaponized by autocratic
• 30:49
  big tech companies that are aligned with petrostates
• 30:53
  in the US. There is a very disturbing alignment
• 30:56
  between a lot of the big tech companies in Donald
• 30:59
  Trump's administration right now, currying favor
• 31:01
  with him so that they can get favorable decisions
• 31:05
  from the courts. It's a scary time. Yes, it is
• 31:14
  a contributor and it isn't just the energy. These
• 31:17
  data centers are, you know, hog fresh water as
• 31:22
  well. They use up tremendous amounts of water.
• 31:25
  They use, you know, large amounts of energy.
• 31:28
  They're taking up resources. They produce pollution.
• 31:34
  If they're polluting the environment and the
• 31:36
  ones who are, you know, at the receiving end
• 31:38
  of that pollution are often the poorest, those
• 31:41
  with the least wealth who can't live anywhere
• 31:45
  else. So from a sort of environmental justice
• 31:48
  standpoint, it's problematic. We could go on
• 31:50
  down the list. There's so many reasons why unregulated
• 31:54
  AI, which is what we have right now. is such
• 31:58
  a threat in so many different ways. Yeah, I don't
• 32:00
  think there's any data centers being built in
• 32:02
  Beverly Hills. Exactly. By the way, my previous
• 32:07
  guest on the podcast, Cory Doctorow, who just
• 32:09
  released a fantastic book on AI, he said how
• 32:13
  the kids, he called them the kids working at
• 32:15
  Elon Musk's Doge, the so -called Department of
• 32:19
  Government Efficiency, slashed a lot of climate
• 32:22
  funds because they said AI will solve... climate
• 32:25
  change anyway. We just need to get there. We
• 32:28
  need to get to AGI as soon as possible. I'm not
• 32:30
  going to lie, but that sounds pretty demented.
• 32:34
  Well, you know, it feeds those dystopian sci
• 32:39
  -fi sort of narratives where one could imagine
• 32:46
  that we do produce an all -knowing, an omniscient
• 32:50
  AI. that, and we charge it with solving the climate
• 32:55
  crisis. This is like, you know, almost a Twilight
• 32:58
  Zone episode, the sort of irony that Rod Serling
• 33:00
  would have sort of brought to the table. We tell
• 33:03
  AI to solve the climate crisis and it does it.
• 33:06
  It gets rid of us. So be careful what you wish
• 33:10
  for is what I would say. It may be that we don't,
• 33:14
  we won't like the solution. You mentioned this
• 33:18
  before, but when Trump won again in 2025, he
• 33:21
  immediately gutted all the environmental agencies
• 33:24
  as well as drained the clean energy and climate
• 33:26
  grants. How bad was Trump's victory for setting
• 33:29
  back U .S.'s climate goals and that of the world
• 33:33
  consequently? Or how has that turn towards climate
• 33:36
  denial manifested on the ground in the U .S.?
• 33:41
  Yeah, it was horrific. And Peter and I talk about
• 33:44
  it in Science Under Siege. I wrote a couple of
• 33:47
  commentaries for the Bulletin of the Atomic Scientists.
• 33:49
  They're outside the paywall. People can go and
• 33:51
  check that out. At the time, I talked about that
• 33:53
  in some detail. What does this mean for climate
• 33:57
  action, environmental policy here in the US,
• 33:59
  but also globally, right? Because if the United
• 34:02
  States, which is the world's biggest legacy polluter,
• 34:05
  don't believe any of the propaganda you hear
• 34:08
  right now. China. They love talking to the climate
• 34:11
  deniers. They love talking about China. China
• 34:14
  is actually doing a whole lot more than us right
• 34:15
  now on renewable energy, on decarbonization.
• 34:18
  And we are the world's largest carbon polluter.
• 34:22
  Cumulative carbon pollution is all the global
• 34:24
  climate system cares about. How much total carbon
• 34:27
  pollution have you produced historically? And
• 34:30
  the U .S. has produced more than any other country.
• 34:32
  We've contributed most to this problem. And when
• 34:35
  we're not taking leadership. as we were under
• 34:37
  Barack Obama, as we were to a good extent under
• 34:41
  Joe Biden, although he faced headwinds, increasing
• 34:44
  headwinds, because polluters have really been
• 34:46
  very effective at creating obstacles to action
• 34:49
  here. But we saw good faith efforts. previous
• 34:54
  administrations, the Obama administration, the
• 34:55
  Biden administration, the Inflation Reduction
• 34:59
  Act, a half trillion dollar investment in clean
• 35:03
  energy really was sort of moving us in the direction
• 35:06
  we needed to go. And the reelection of Trump
• 35:10
  brought all of that to a standstill. In fact,
• 35:13
  what they're now doing, what they've been doing
• 35:15
  over the past year, and keep in mind that Donald
• 35:18
  Trump is just a figurehead. The people who put
• 35:20
  him in power, the fossil fuel industry, are the
• 35:23
  plutocrats like the Koch brothers and the Mercers
• 35:26
  and the rest of them that have this right -wing
• 35:30
  libertarian deregulatory philosophy. And they
• 35:35
  just want a president who's going to give them
• 35:37
  what they ask for. And Donald Trump was that
• 35:39
  president. So if you read, for example, Project
• 35:42
  2025, and I wrote a commentary about... Project
• 35:45
  2025. It was written by the polluters. It was
• 35:48
  written by the plutocrats. And it was basically
• 35:50
  the how -to guide for the Trump 2 .0, what they
• 35:55
  wanted Trump to do. And what they wanted him
• 35:58
  to do in particular was to defund environmental
• 36:00
  science and climate science, get rid of environmental
• 36:04
  regulations, turn the clock back on environmental
• 36:07
  sort of protection going back a half century,
• 36:10
  even now. eradicating policies that were put
• 36:16
  in place by prior Republican administrations
• 36:18
  like Reagan and Nixon. to deal with environmental
• 36:21
  problems. And so we have seen, you know, and
• 36:27
  obviously an end to all of the incentives that
• 36:31
  had been put in place to help us move towards
• 36:33
  renewable energy, literally canceling wind farms
• 36:36
  that are nearly done and paying energy companies
• 36:39
  money to cancel their clean energy projects and
• 36:42
  replace them with fossil fuel projects. I mean,
• 36:45
  it's almost, it would be. comical if it weren't
• 36:49
  so obscene, the measures that they are taking
• 36:51
  to turn back the clock. And when the United States
• 36:54
  says to the rest of the world that it's not going
• 36:57
  to do its part, that makes it really challenging
• 37:01
  to convince other countries that don't have the
• 37:03
  legacy, that didn't have 200 years of free fossil
• 37:06
  fuel energy to build their economies with. It
• 37:09
  makes it really hard to tell them that they shouldn't
• 37:12
  have the same opportunity. Fortunately, One of
• 37:15
  the things that gives me a little bit of hope
• 37:17
  is despite all of that, China sees an opportunity
• 37:20
  here. I think they see an opportunity to be the
• 37:23
  adult in the room. They see an opportunity to
• 37:26
  be, you know, the United States used to call
• 37:30
  itself the leader of the free world, whatever
• 37:32
  that means. But I think China sees an opportunity
• 37:35
  now to be the leading country on this planet.
• 37:39
  And they're seizing that opportunity and they're
• 37:41
  moving ahead and they're taking advantage. Getting
• 37:45
  out ahead on the greatest revolution of this
• 37:47
  century, the clean energy revolution, while the
• 37:50
  United States is left behind. Here's the bottom
• 37:53
  line. In the end, I think the United States no
• 37:57
  longer gets to determine what happens here writ
• 38:01
  large. They only get to determine whether they
• 38:04
  get on board or get left behind at the station.
• 38:08
  Why do you think climate denial still exists
• 38:10
  in 2026? We talked before about how even an ordinary
• 38:14
  person such as myself can notice how dramatically
• 38:17
  the weather has changed in the past couple of
• 38:20
  decades. But yet there are still people out there
• 38:23
  who are saying that this is all within like natural
• 38:26
  parameters. I heard Joe Rogan say the other day
• 38:30
  that actually we're in a cooling period. Facts
• 38:34
  no longer matter, right? Carl Sagan presaged
• 38:36
  this decades ago in Demon Haunted World. He presaged
• 38:40
  a future like this where people no longer have
• 38:43
  the critical faculties to even figure out what's
• 38:45
  right or wrong, and they easily fall prey, they
• 38:48
  fall victim to bad actors spreading propaganda,
• 38:52
  misinformation, disinformation. Most of the people
• 38:54
  spreading it know better, but the people who
• 38:57
  are consuming it, they don't. They're the victims
• 39:00
  in some sense. We're all the victims. And so
• 39:03
  we now live in this truth -free world where Donald
• 39:07
  Trump can say something. He can say, you know,
• 39:09
  up is down, black is white, the sky is green.
• 39:13
  It doesn't matter. His followers accept whatever
• 39:17
  he says as an article of faith, really. And that's
• 39:21
  a very dangerous place for us to be right now.
• 39:24
  And so we saw the sort of... We saw that coming
• 39:29
  in a sense in climate science more than two decades
• 39:32
  ago, the sort of the way that lies and myths
• 39:36
  were so readily spread by, again, bad actors
• 39:41
  who have access, who have own. you know, social
• 39:45
  media and media outlets with which they can spread
• 39:48
  misinformation and disinformation. Bad actors
• 39:51
  like Russia and Saudi Arabia that spread disinformation
• 39:54
  online on social media. It's not a coincidence
• 39:57
  that Russia and Saudi Arabia helped Elon Musk
• 40:00
  buy Twitter. It was so they could weaponize Twitter
• 40:02
  for the spread of their disinformation. And so
• 40:06
  we live in this world. And again, AI now, machine
• 40:11
  learning and AI. offers the prospects for that
• 40:14
  disinformation to go infinite now, to just sort
• 40:19
  of to be propagated at a rate that we can't possibly,
• 40:24
  you know, this fire hose of disinformation that
• 40:27
  there's just no way for us to push back against
• 40:29
  the lies and to inform people in the presence
• 40:32
  of this fire hose of lies. And that's what, to
• 40:36
  me, that's the greatest danger right now, because
• 40:38
  everything else we care about, the environment,
• 40:40
  climate, public health. Everything else goes
• 40:43
  to the wayside if we can't get a hold of this
• 40:46
  problem, if we can't return to a good faith,
• 40:51
  fact driven discourse. It's interesting because
• 40:55
  you're much more hopeful on the climate side
• 40:57
  than I thought you were going to be. But you
• 40:59
  seem less hopeful when it comes to society and
• 41:02
  politics. Well, yeah, here's the difference.
• 41:05
  One is physics and the other is, you know, the
• 41:08
  laws of physics are immutable. They are what
• 41:10
  they are. And I'm. As a climate scientist who's
• 41:13
  studied climate science for decades, I'm familiar
• 41:19
  enough with those physics to know that that at
• 41:21
  this point is not the real threat. The physics
• 41:25
  isn't what's holding us back. It's the politics.
• 41:28
  And there, there's a crack in the door. There's
• 41:31
  an opportunity. There's a glimmer of hope because
• 41:33
  we can take hold of our politics. I think something...
• 41:40
  Very important is going to happen here in the
• 41:42
  U .S. in the midterm elections just a couple
• 41:45
  of months from now that will fundamentally change
• 41:48
  the path that we are on here in the United States
• 41:51
  with implications for the rest of the world.
• 41:53
  So I am not a doomer either on climate or on
• 41:57
  our ability to survive the challenges we face.
• 42:00
  But I do think we are at a critical juncture.
• 42:03
  And the next several months, in fact. are going
• 42:07
  to be critical to determining whether we sort
• 42:11
  of right the ship and get off this dangerous
• 42:14
  path that we're on or not. Talk to me in mid
• 42:19
  -November and I'll be able to give you a more
• 42:25
  confident prognosis as to where I think we're
• 42:29
  headed. be my last question then. Doomers. That's
• 42:35
  a subset of people who believe in climate change,
• 42:38
  but they also believe it's too late and that
• 42:40
  we should abandon all hope, stop organizing and
• 42:42
  go live in the woods or something. How do you
• 42:46
  comment on that kind of phenomena? Because from
• 42:51
  my perspective, it does seem to drain a lot of
• 42:54
  the energy and hope out of a lot of people who...
• 42:59
  otherwise earnestly try to maybe organize or
• 43:02
  participate in something or believe that it's
• 43:06
  not too late. So I just want to hear your thoughts.
• 43:09
  Yeah, no, absolutely. In fact, I was going to
• 43:11
  try to find, where is it? The headline that ran
• 43:16
  in the Telegraph. It was, Britain can't stop
• 43:23
  climate change. Let's just embrace a Mediterranean
• 43:26
  lifestyle. I mean, just execrable headline that
• 43:34
  just embodies so many different denialist and
• 43:37
  deflective tropes at the same time. But note
• 43:43
  the doomism, right? They're feeding that doomism.
• 43:46
  Britain can't do anything about this. And so
• 43:49
  understand if you've fallen victim to doom, and
• 43:52
  it's understandable, and a lot of good people
• 43:54
  have. I have at times as well. Again, bad actors
• 43:59
  are doing is they're preying upon that. They
• 44:02
  want you to fall victim to doomism. They want
• 44:06
  you to feel hopeless. And that's true right now
• 44:08
  with the assault on American democracy. The Trump
• 44:10
  administration and those behind this autocratic
• 44:13
  assault want us to feel hopeless. They're doing
• 44:17
  everything they can to make us feel powerless
• 44:19
  and hopeless because that's disabling. That leads
• 44:23
  to disengagement. They want us disengaged. So
• 44:26
  understand. if you've fallen victim to doom,
• 44:30
  that the bad actors want, that's where they want
• 44:33
  you. They want you to give up hope because then
• 44:37
  you're not there on the front lines demanding
• 44:39
  action. You're on the sidelines, which is where
• 44:41
  they want you. So here is the bottom line. And
• 44:45
  I think this is a reason for not Pollyannish,
• 44:48
  you know, hope, but real hope is the fact that
• 44:53
  at this point, The obstacles, as I said, they're
• 44:56
  not physical. They're not technological. We've
• 44:59
  got the technology to decarbonize our world.
• 45:03
  They're not physical. They're not technological.
• 45:05
  They're political. And political obstacles can
• 45:09
  be overcome. It's up to us. That is up to us.
• 45:14
  I do love ending on a hopeful note. Professor,
• 45:17
  thank you so much for taking the time. I know
• 45:18
  how incredibly busy you are. I really appreciate
• 45:20
  it. No worries. Always great talking with you.