A Look at Some Climate Tipping Points

After all the damage caused by extreme natural disasters in 2022, including Hurricane Julia in Central and South America and deadly floods in Nigeria and Australia, it’s challenging to envision how climate change could get any worse. However, a group of scientists have imagined some worst-case scenarios and published a study in Science journal focusing on climate tipping points. That report brought both good and bad news. In this “Tip of the Iceberg” episode, host Ethan Brown examines the climate trajectory we’re on and highlights some significant progress.

For more information, see the companion “Tip of the Iceberg” essay here


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ETHAN: Last week, Katmai National Park celebrated Fat Bear Week, which is Alaska’s answer to Shark Week that also includes body shaming. Just kidding – it’s actually an annual event where people around the world tune in to see brown bears bulk up for hibernation and vote on which bears were the chonkiest. Unsurprisingly, the winner was an absolute unit. And in a shocking turn of events, two of the mama bears actually became friends, which isn’t something brown bears generally do. Mama brown bears typically compete for PTA President and sabotage each other’s bake sales. But this is a heartwarming story, and I really wanted to make today’s episode about that, which made it all the more frustrating that Fat Bear Week got completely overshadowed by what can only be described as Climate Gloom Week. Seriously, every time I want to do an episode about animals becoming friends, another deadly flood happens. Unless this is a Noah’s Ark situation and the floods are causing the friendships, I’d really appreciate it if the climate would just chill out.

ETHAN: In all seriousness, we’ve got an episode just as exciting as bears becoming friends for you today. Good Wednesday morning, I’m Ethan Brown, and this is Tip of the Iceberg, where I will break down some environmental news and then answer a question from our listeners on the air. Submit questions via Patreon, email, or social media. Patron questions go to the front of the line, so sign up at patreon.com/thesweatypenguin.

ETHAN: The Sweaty Penguin is presented by Peril and Promise: a public media initiative from The WNET Group in New York, reporting on the issues and solutions around climate change. You can learn more at pbs.org/perilandpromise. 

ETHAN: I am obligated to discuss floods and hurricanes when they happen, but that doesn’t mean hurricanes can’t be fun and heartwarming! Actually like the mama bears, last week Hurricane Julia and Hurricane Fiona became friends in the bathroom of a club. This Atlantic hurricane season is like the messiest friend group you know. They think they’re living out the plot of Euphoria but they’re actually just annoying and destructive. Last week, we found Hurricane Julia who was still on her crazy drunken bender, crashing in Trinidad and Tobago, Venezuela, Colombia, Honduras, Guatemala, Nicaragua, Panama, and El Salvador. Julia, this was supposed to be an immersive study abroad trip but you’re destroying everything in your path and you haven’t even learned any Spanish! Julia’s winds didn’t reach the levels of Hurricanes Ian and Fiona, only registering as category one, but the hurricane still created significant damage, caused at least 76 deaths, and exacerbated deadly landslides in Las Tejerias, Venezuela. 

ETHAN: Meanwhile, flooding in Nigeria caused in part by extreme rains has worsened over the last week, having now claimed 500 lives, injured 1,546 people, inundated 70,566 hectares of farmland and “totally damaged” 45,249 homes. Southeastern Australia has been hit with deadly floods yet again. Pakistan is starting to drain, but still reeling from the impacts of the floods we discussed a month and a half ago. And, of course, the recovery efforts from Hurricanes Fiona and Ian are just beginning. With all of these catastrophes and more, I would not be surprised if many of you are starting to ask some fair but difficult questions: first, will Sam Levinson be using Julia and Fiona as inspo for a spinoff. But second, seeing how bad this damage has been, it’s hard to wrap our heads around the idea of it getting any worse from here, right? If we let climate change run wild, if we did nothing, how bad could climate change get?


ETHAN: Don’t turn off the episode right now, this is purely a hypothetical. Let me be very clear about this. At the present moment, the world is about 1.1 degrees Celsius hotter than pre-industrial times. Before 2015, we were on track to warm the planet nearly 4 degrees Celsius by 2100. But thanks to clean energy growth and current policies, we’ve already slashed that projection to about 2.6 degrees Celsius by 2100, which is significant progress. And that number could, and I think will, continue to come down. Every country in the world has agreed on a goal of limiting global warming to 1.5 degrees Celsius. That would require more pledges and more action, but absolutely remains achievable. So when I ask “how bad can it get,” remember the progress we’ve made so far and remember that countries have pledged to continue making progress. I don’t want to get into dystopian stuff and have you think that’s our fate. It’s not. We just have to keep working to prevent it.

ETHAN: Keeping all that reason for hope in mind, let’s take a look at a study that came out in the journal Science a month and a half ago which asked this very question: how bad can it get? To answer the question, the authors of this study looked at something called positive feedback loops. And no, this is not where you and your bestie go back and forth hyping each other up. Let me give you an example of what this is. We all know global warming causes sea ice to melt. In addition to other consequences, when ice melts, it becomes water which is darker in color. With that happening to the extent it is, the overall surface of the Earth is becoming darker. Now, if you’ve ever made the mistake of wearing a black shirt on Field Day in 4th grade where you have to do the potato sack race on the sunniest day of the year, you know that the darker something is, the more sunlight it absorbs. So the surface of the Earth is darker, meaning it absorbs more sunlight, which makes it hotter, which then drives more ice melt, which makes the Earth’s surface even darker, and now we’ve entered a positive feedback loop. A disturbance is exacerbated because it kicks off one of these cycles.

ETHAN: Not every positive feedback loop is infinite, though. Nature is remarkably resilient. We’ll see ice melt in the summer, but it can re-freeze  in the winter. Coral reefs may undergo bleaching events, but they can bounce back to life. Trees in a forest may burn down in a wildfire, but Smokey will always survive and plant new trees. He cannot be destroyed by the elements and he is immortal. But with each of these scenarios, there is a point at which nature can’t keep up, which has led climate scientists to develop the concept of a “tipping point.” A tipping point is a threshold where a positive feedback loop is kicked into motion to the point where it can’t stop, and it ends up causing irreversible damage. Nature can’t bounce back.

ETHAN: So this study in Science assessed more than 200 previous studies to put together a list of sixteen climate tipping points. Starring Molly Ringwald, Sixteen Tipping Points is a coming of age comedy where everyone forgets about Mother Nature’s birthday, so she floods all their houses. No, it’s a comedy, I swear. After these scientists identified these sixteen tipping points, they then asked at what degree of warming would each tipping point be set off. Given how complicated the climate system is, that’s not a question that can be answered with complete precision, but these scientists were still able to come up with some useful answers. The bad news is that four of the sixteen tipping points are likely to be set off at 1.5°C of warming, and may have been hit already. These would be the collapse of the Greenland and West Antarctic ice sheets, the complete die off of tropical coral reefs, and the abrupt thawing of the northern permafrost. The permafrost, if you’re not familiar, is a layer of ice under the soil in the Arctic that has trapped an estimated 1.4 trillion tons of carbon. Without the permafrost trapping that carbon, we could see it enter the atmosphere.

ETHAN: What if we stayed on the current trajectory and warmed by 2.6°C? Then, we would be likely to hit three more tipping points, and a few more would start to become possibilities. We’d be very likely to hit the loss of mountain glaciers, abrupt ice loss in the Barents Sea, and the collapse of ocean currents in the Labrador Sea. Although you’d think is the Labrador Sea lost its ocean currents, it could just… retrieve them. Another seven feedback loops would be likely to get set off around the 3-4 degree range, and the remaining two would be likeliest in the 6-8 degree range.

ETHAN: I remember when this study came out, there seemed to be some grief. And that’s totally reasonable. Whatever we do at this point, we are likely to see the collapse of the Greenland and West Antarctic ice sheet, the die-off of tropical coral reefs, and the abrupt thawing of the northern permafrost. And that’s bad. I am not going to minimize that at all. Hitting any one of these sixteen tipping points means more of these aforementioned hurricanes, floods, and natural disasters that are getting worse and worse.

ETHAN: But if you’ll allow me to be Mr. Optimist for a second. Remember what I said earlier. In 2015, we were on track to warm the planet by 4°C. That warming would likely hit 14 out of these 16 tipping points. But we made progress since then. We’re currently on a trajectory to warm by 2.6°C, which would lead us to hit seven tipping points, with the possibility of a couple more. And that means in just seven years of innovation, investment, and policy, we may have halved the number of worst case scenarios. Does that mean we can let up? Not at all. “On track to contain global warming to 2.6 degrees” does mean we’ve already done it, and life would be a hell of a lot better if we kept working that number down into the 1.5 range. But it’s still encouraging to me that we’re making progress. We can acknowledge what we’ve lost, but be inspired by what we’re poised to protect.

ETHAN: You may have heard last week about climate protesters who threw soup on Van Gogh’s “Sunflowers” painting at the National Gallery in London. I personally am most outraged because… I called dibs on that soup. This incident sparked interesting discussions in the climate community about if these extreme protest tactics are effective or damaging. I’m not an activist, so I don’t know the answer, but I heard a lot of people say how this protest could backfire, and make ordinary people frustrated with climate advocates and less likely to engage as a result. On the other hand, the rebuttal I kept seeing was along the lines of, “well, nobody cares right now anyway. We’re headed for the apocalypse. Those protesters had nothing to lose.” Which, like, even if you believe that, at least throw the soup at an Andy Warhol. 

ETHAN: But going off what this study found about tipping points, I just can’t look at it way. People do care! We’ve moved the needle. Is it still bad? Yes. But it could be worse. It could be a LOT worse. And it isn’t. Because of progress we’ve made. I don’t want to go overboard talking about worst case scenarios when we’re poised to avoid so many of them, but it’s good scientists are asking that question, and I think what could have been a pessimistic study actually turned out to be somewhat encouraging. Is it as heartwarming as two bears becoming friends? I don’t know, but if Molly Ringwald is starring in Sixteen Tipping Points, I think it has a fair shot.

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ETHAN: The Sweaty Penguin is presented by Peril and Promise: a public media initiative from The WNET Group in New York, reporting on the issues and solutions around climate change. You can learn more at pbs.org/perilandpromise. 

ETHAN: Welcome back to Tip of the Iceberg. It’s time for “Ask Me Anything,” where our listeners get a chance to ask me any environmental questions they may have. Submit questions on our Patreon, email, or social media. Questions from patrons go to the front of the line, so be sure to sign up today at patreon.com/thesweatypenguin.

ETHAN: As you all know, we did a live show in August to celebrate episode 100, and today’s Ask Me Anything comes from that show! Have a listen: 

ETHAN: I see we’ve got a hand already. If you wanna take the mic…

AUDIENCE MEMBER: Sure, thanks. Um, what’s your hot take on the Inflation Reduction Act?

ETHAN: What’s my hot take on the inflation Reduction Act. Coming out strong! Thanks so much for the question. I appreciate it. So yeah, the inflation reduction act just passed the House yesterday, I believe. And I think that it’s actually very hard for me to come up with hot takes on environmental policies that are widely agreed upon. And this is a little bit of a wonky situation, because the actual politicians don’t all agree on it. But there was some polling that I saw, I believe it was around 73% of Americans support the inflation Reduction Act, including 52% of Republicans and 95% of Democrats. So in that sense, in my head, it kind of blends in with a lot of other widely agreed upon things. And with The Sweaty Penguin, my goal has always been to bring people in, engage them on climate help find common ground, and then send you on your way to other people. So once people have found common ground, it can be hard for me to really jump in and have a strong opinion. What I think is interesting about this bill, though, is got climate change inflation. And a lot of people may not know how that fits together, right. And I think that’s what’s interesting. So this is all in theory about how the bill could tackle inflation. And in the short term, there is certainly measures in there such as reducing the deficit, and bringing healthcare costs down that are more directly targeted at that. But in the long term, looking at things like addressing climate change, a big driver of inflation has actually been extreme heat and extreme weather events. So that can create issues with shipping, it can create food crises, food has been one of the biggest drivers of inflation this year. And that’s, that’s not great. So in addressing climate change, for looking to the long term, that actually does kind of help with inflation. And I think that’s kind of an interesting angle that I haven’t seen talked about a lot. I talked about it a little bit on Wednesday. So I encourage you to check that out. But yeah, that’s maybe the hottest take that I’ve got on it right now. 


ETHAN: If I can add one more thing, I wrote an Op-Ed last month for Real Clear Energy about the fact that in the one-pager explaining the Inflation Reduction Act, lawmakers claim it will reduce carbon emissions by roughly 40 percent by 2030. That’s not really true. And I didn’t know at the time of recording that live show just how misunderstood this was. In using this statistic, they are referring to a 40 percent reduction from 2005 emission levels, when United States emissions were at their peak. From 2005 to 2019, U.S. emissions dropped by about 16 percent. By 2030, emissions would have continued to drop under policies predating the Inflation Reduction Act to 24 to 35 percent below 2005 levels according to an analysis from the Rhodium Group. Is turning 24 percent into 40 percent a big deal? Absolutely. But without that context, I worry that lawmakers may be trying to take credit for a lot more than maybe they should be.

ETHAN: And this goes back to that “nothing to lose” point I was making before. We are making progress. I saw news outlets referring to the Inflation Reduction Act as the nation’s first major climate law, but that’s just not the case. In the last few years alone, the U.S. passed bipartisan laws including the Infrastructure Investment and Jobs Act, USE IT Act, BEST Act, Nuclear Energy Leadership Act, and Great American Outdoors Act, all of whom had climate implications. I know none of these were advertised as climate laws, but neither was something called the “Inflation Reduction Act.” And on top of that, the bulk of our climate action has come from the private sector, where we’ve seen the costs of clean energy drop considerably over the last decade.

ETHAN: I really tried to make a slightly more pessimistic episode today, but my research really swung me in the other direction, as it always does. That would be pretty depressing if the Inflation Reduction Act were the first major climate law, but it really isn’t. And I hope in using this misleading “40 percent by 2030” statistic, lawmakers don’t start taking success for progress they had nothing to do with. It might seem like a way to score political points, but it isn’t worth leaving people in the dark about decades of progress we’ve been making on climate that could actually get them a lot more excited.

ETHAN: Thanks so much for the question. And thanks to all of you who listened to Tip of the Iceberg. Take two minutes, help out the show, and get a shoutout at the end of the show by leaving a five star rating and a review on Apple or Podcast Addict OR join our Patreon at patreon.com/thesweatypenguin. You get merch, bonus content, and your questions moved to the front of the line for Tip of the Iceberg. The Sweaty Penguin is presented by Peril and Promise: a public media initiative from The WNET Group in New York, reporting on the issues and solutions around climate change. You can learn more at pbs.org/perilandpromise. The opinions expressed in this podcast are those of the host and guests. They do not necessarily reflect the opinions or views of Peril and Promise or The WNET Group. Thanks so much for listening, and I’ll see you on Friday for a deep dive on another carbon bomb. We’ll be traveling to Venezuela to discuss the Orinoco Belt. This is the highest emitting carbon bomb in South America and a very important region of the world to discuss, so I will see you there.