UN Report Confirms 2023 Was Hottest Year On Record

IRA FLATOW: This is Science Friday. I’m Ira Flatow. Later in the hour, what happens when an endangered plant is poached from the wild and then is illegally transported into the US? We’ll talk with botanists who run a plant rescue program. Plus, diving into how sea lions swim and why understanding the physics of their strokes may provide inspiration for better underwater vehicles.

But first, a new report from the world meteorological organization shows that last year had the hottest average global temperatures since they were first recording stuff 174 years ago. Wow. Most concerning is a rise in ocean temperatures. And 2024 is on track to break last year’s records.

Joining me to talk about that and other top science news of the week is Jason Dinh, climate editor at Atmos Magazine, based in Washington. Welcome back to Science Friday.

JASON DINH: Thanks for having me, Ira.

IRA FLATOW: You were our NSF fellow.

JASON DINH: I was.

IRA FLATOW: Yes, nice to have you back. Let’s get right into this. It’s really interesting. Break it down for me. What were the big takeaways from this latest UN Climate Report?

JASON DINH: Yeah, so in this report, the WMO secretary general says that they’re, quote, “Sounding the red alert to the world.” The report documents that nearly every single climate record was broken in the last year. So that includes greenhouse gases, land temperatures, water temperatures, glacial melt, sea level rise. Basically, you name it, it was probably broken.

These record-breaking conditions were in part due to the El Niño climate patterns that we saw in the last year. But it’s also clear that the big drivers are really greenhouse gases and human-caused climate change.

And maybe the most troubling part of all of this is that the WMO says that 2024 might even be worse, right? We’re still emitting tons of greenhouse gases into the atmosphere. And the year after El Niño does tend to be warmer than average. So in January, we’ve already seen the hottest January on record. February was the hottest February on record. And just last week, global sea surface temperatures broke daily records for a whole year straight.

IRA FLATOW: There’s the cynic in me that says, OK, we’ve heard all of this before. Is anybody going to take any action?

JASON DINH: Yeah, so the WMO does acknowledge that there is a glimmer of hope. So renewable energy capacity from wind and solar and hydro rose nearly 50% between 2022 and 2023. And it’s also worth noting that even if we pass this pretty dangerous benchmark of 1.5 degrees Celsius of warming, it is still worth it to fight for a rapid and a just transition to clean energy because every 10th of a degree beyond that we hold onto really is going to save countless lives.

IRA FLATOW: And another bit of not so great climate news– I hate to keep piling on– a report by the IQAir people– they’re a Swiss air quality organization. And they have found that only 7 of 134 countries they monitored met the WHO guidelines for air quality. Whoa. Can you rank the countries for us? Who’s the worst?

JASON DINH: Yeah, sure. Well, the best were Australia, Estonia, Finland, Grenada, Iceland, Mauritius, and New Zealand. And this report, it was based on 30,000 monitoring stations that were measuring what are called PM 2.5. They’re sometimes called fine particulate matter. These are basically tiny particles, 2.5 microns. So that’s smaller than the width of a human hair.

These are really dangerous. They kill about 4 million people each year globally. And the World Health Organization says that the safe standard for this is about 5 micrograms per cubic meter. In the worst-case scenario in Bangladesh, the level was about 15 times that. And even here in the US, where we’ve seen things like the Clean Air Act and renewable energy really improve our air quality, we’re still at around 9 micrograms per cubic meter. So that’s almost double the standard.

IRA FLATOW: Who is the worst country?

JASON DINH: The worst country was Bangladesh, which is around 15 times. And Pakistan was just right behind it at 14 times higher.

IRA FLATOW: Well, it’s not all terrible news, though. Air quality has improved in the last half century.

JASON DINH: Yes, exactly. Air quality has really improved thanks to some really great legislation, like the Clean Air Act. The caveat to that is that climate change really is biting back a little bit. So we know that as the climate changes, air is starting to stagnate in certain places, which allows these pollutants to accumulate.

And we’re also seeing more severe and frequent wildfires, which themselves are a source of PM 2.5. So if you look at the report, Canada actually has worse air quality than the US, in part due to those wildfires that turned the skies orange last year.

IRA FLATOW: Who can forget that? We’re hoping that doesn’t happen again. Let’s shift our focus a bit to an infectious disease outbreak in Brazil. And I’m talking about dengue fever. The country plans to release mosquitoes infected with a bacteria to six cities to help stop the outbreak. Tell us how that works.

JASON DINH: Yeah, so Brazil is really going through this unprecedented outbreak of dengue fever, which is this viral disease that’s spread by the mosquito Aedes aegypti. And so far in 2020, 1 and 1/2 million people have caught the disease. That’s the total of last year’s cases combined.

So according to reporting from The Guardian, Brazil is fighting back by releasing these mosquitoes that are infected with a bacterium called Wolbachia. They’ve nicknamed them wolbitos. And they’ve shown that these mosquitoes that are infected with Wolbachia are actually less likely to transmit dengue to people.

So their plan is to release these small batches of wolbitos into the wild, where they’ll mate with the natural population. And they actually pass on the bacteria to their offspring through their eggs. So every generation, you’re getting more and more coverage of wolbitos in the city.

They piloted this in 2015. And they’ve released them into five cities in 2017. And now with this major outbreak, they’re going to release them in six more.

And thanks to these earlier projects, we already have evidence that it’s kind of working. So if you look at the city of Niteroi, they hosted the pilot projects in 2015. And they’re the first city to have full coverage of wolbitos. This year, they’ve only seen 689 probable cases of dengue. And if you compare that to Rio, which is less than 100 miles away and where the Wolbachia trial is at a much smaller scale, Rio has seen over 60,000 probable cases, so 100 times more dengue despite only 12 times more people.

IRA FLATOW: Let’s continue with the animal kingdom for a while. A new study about the Eurasian hoopoe. I don’t think a lot of people have seen the Eurasian hoopoe. It’s a bird, right? The bird has some pretty brutal behavior, cannibalism.

JASON DINH: Yes.

IRA FLATOW: Bird cannibalism.

JASON DINH: Bird cannibalism. Even worse, it’s sibling cannibalism. So the European hoopoe is this really beautiful orange-crested bird. And it gets its name for its whooping sound. And it does this really gruesome, peculiar thing, which is that chicks will eat their siblings while they’re in the nest.

IRA FLATOW: Wait, wait, maybe back that up for a second. The chicks will eat their siblings. So you have a nest full of chicks. They’re going to eat each other.

JASON DINH: Yes, exactly. The mothers will grab the younger chicks, and they will literally shove them into the mouths of the older ones, who will swallow them whole. And so what these researchers wanted to do was figure out if there is any benefit to this pretty macabre behavior.

So they did a couple of experiments using these hoopoe nests. The most critical one is that they moved eggs from one nest to another. And they carefully timed it so that that transferred egg would be the last one to hatch in its new brood by just one day. And they found that that chick was always eaten, as was the chick that was the next youngest.

And what was most interesting about this is that the nests that received an extra egg fledged on average two more birds than the nest where the egg was removed. What they think that means is that sibling cannibalism actually does have reproductive benefits as long as you’re on the right side of the eating equation.

IRA FLATOW: I’ll say. I never realized how much of a bird-eat-bird world it is.

JASON DINH: It is a bird-eat-bird world, Ira.

IRA FLATOW: All right, let’s move on to the next story that you brought us. And this is about evolutionary advantage of whales going through menopause. I didn’t know any of that happened. Tell me about that.

JASON DINH: Yeah, honestly, I didn’t know this happened until this study came out either. So this study came out in Nature last week. And it gets us one step closer to figuring out why menopause evolved.

Evolutionarily speaking, menopause is really counterintuitive, right? If your goal is to have your DNA as widespread as possible in the next generation, then why don’t you just keep having offspring until you die? That’s what most mammals do, actually, all except for humans and five other species, all of which happen to be whales. So this includes killer whales, false killer whales, beluga whales, short-finned pilot whales, and narwhals. And there is one exception with one population of chimpanzees as of last year.

So this study looked at those five whale species and compared them to 27 nonmenopausal ones. And they asked, is there an advantage for the species that go through menopause? They figured out things like how old the whales are and whether they’re still making eggs. And really, their big finding is that while menopausal whales reproduce as long as non menopausal ones of the same size, these menopausal whales lived 40 years longer, which suggests that natural selection is favoring mutations that are actually tacking on years to a whale’s life after reproduction stops.

IRA FLATOW: That’s amazing. 40 years longer.

JASON DINH: 40 years longer, yeah. And it’s still not 100% clear what the benefit of living that long after you stop reproducing is. There are a couple of theories.

So one that I like is that the grandmother whales are actually helping their relatives. So we’ve seen older killer whales teach younger ones how to hunt, how to take long journeys and even share their food. We can’t make conclusions based on this study, especially because this study is based on dead whales. And we have to be pretty cautious about what kind of conclusions we’re drawing. But outside experts have said that this is a pretty ingenious way at figuring out whatever we can from what little data we can scrap together.

IRA FLATOW: Mother nature is doing her thing. This last story is about the opposite end of the life cycle. And I’m talking about kitten season is beginning earlier and earlier. And as a result, rescue organizations are struggling to keep up. What’s going on? First, tell us what kitten season is and what’s happening there.

JASON DINH: Yeah, so this comes from some really great reporting from Sachi Mulkey at Grist. And what her reporting showed is that kitten season, when cats are most reproductively active, in the warm months between spring and fall, is beginning months earlier than it normally does. And it’s lasting longer. And while this seems totally adorable, it is really putting a strain on the animal shelters who are strapped with resources to deal with this influx.

Some researchers think that climate change might be to blame. So one hypothesis is that as it gets warmer, resources, like food and rodents to eat, are becoming more abundant, which could give the cats more nutrients that they need to start breeding. And, of course, all of this is bad news for biodiversity. Outdoor cats eat basically everything. And they’re driving a bunch of species extinct.

It’s too early to say whether climate change really is to blame. But I can speak for both me and my cat in saying that we’re both waiting with bated breath to find out.

IRA FLATOW: So will you all, then, be adopting a cat or two?

JASON DINH: You know, Ira, if there’s anything I’m willing to do to save this world, it’s welcome more cats into my home.

IRA FLATOW: There you go. Thanks, Jason, for taking time to be with us today.

JASON DINH: Thanks for having me, Ira. It’s a pleasure.

IRA FLATOW: Jason Dihn is climate editor at Atmos Magazine, based right here in Washington.

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