Kendra Pierre-Louis: For Scientific American’s Science Quickly, I’m Kendra Pierre-Louis, in for Rachel Feltman. You’re listening to our weekly science news roundup.
First up, the European Union’s Copernicus Climate Change Service reported last Monday that 2025 is shaping up to be the second-hottest year on record, with data suggesting it will tie with 2023 for runner-up status. To learn more about what this means, we are talking to Andrea Thompson, senior desk editor for life science here at Scientific American.
Hi, Andrea.
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Andrea Thompson: Hi, Kendra.
Pierre-Louis: Thanks for joining us today. So yeah, can you tell me more about what the European climate agency found?
Thompson: Yeah, so the agency looked at global average temperature through the end of November for the year and found that we’re at about 1.48 degrees Celsius above preindustrial, which is roughly the last half of the 19th century. And that puts us right now tied with second place for 2023 in terms of where we rank in the hottest years on record. The record holder is, of course, last year, 2024, which was the first year to breach 1.5 degrees Celsius.
Pierre-Louis: And why does that 1.5 degree Celsius number matter?
Thompson: So that is the number that the Paris climate agreement, which was negotiated in 2015, 10 years ago, sort of set as an ambitious goal. So the overall goal was to keep temperature rise under 2 degrees Celsius …
Pierre-Louis: Mm-hmm.
Thompson: Above preindustrial but to aim for under 1.5 degrees Celsius. So this was the first year that hit above that level.
Pierre-Louis: And why does that number—kind of zooming out a little bit more generally—like, why does it matter that the Earth is warming up this much? Should we be concerned?
Thompson: We should absolutely be concerned. We can already see the effects of climate change in the weather.
Pierre-Louis: Mm-hmm.
Thompson: We experience climate disasters. It is probably most easily discernible in heat waves: We experience them more frequently. They’re hotter. They last longer than they used to. But it shows up in a lot of different climate extremes in terms of flooding, drought, wildfires, and the sort of fingerprints of climate change are becoming increasingly clear in all of those kinds of disasters.
And of course, it has a lot of other impacts, too. It affects agriculture. It is affecting ecosystems in ways that come back to humans and everything from, you know, fisheries—whether a fishery collapses because fish have moved away to more climate waters—to whether our infrastructure can handle the climate it’s sort of facing now when it was built for a climate that doesn’t exist anymore.
Pierre-Louis: When they made this announcement, was there anything in particular that they noted or anything that they wanted to, like, call out that the average person should be aware of?
Thompson: Yeah, so I mean, there are a couple other things. The 10 hottest years on record have all happened basically in the last decade, and pretty much all of the hottest years are in this century, so it shows how much climate change has made a difference in the global average temperature but then what we’re all experiencing every day. We will likely have the first three-year average above 1.5 degrees C, so that is sort of moving towards where we’re going to breach the Paris climate agreement.
I think a lot of agencies always note this when they put out these temperature records, that the—whether we continue to break these records and by how much is entirely a matter of the path we choose. So the more we rein in greenhouse gas emissions, mainly by stopping burning fossil fuels, you know, the less likely we’ll continue to break these records by larger and larger amounts.
Pierre-Louis: Thank you so much for taking the time to speak with us today.
Thompson: Thanks for having me.
Pierre-Louis: In other news, the U.K. Health Security Agency says it has detected a new strain of mpox in an individual who had recently traveled abroad. The virus spreads from close physical contact with an infected person, has two types, or clades. Clade I is endemic to Central Africa and has historically been deadlier. The typically less severe Clade II is endemic to West Africa. The clades are further broken down into smaller subtypes: clade IA and IB and clade IIA and IIB. Clade IIB is driving the current global outbreak that began in 2022 and has led to nearly 170,000 cases of mpox through October of this year, according to data from the World Health Organization. WHO reports there have been nearly 48,000 confirmed cases of mpox globally in 2025 so far.
The new strain identified in England contains elements of clade IIB and clade IB. The latter has recently shown some signs of local transmission in parts of Europe and the U.S., according to U.K. health officials. Researchers don’t yet know what impact the new strain could have on transmission. The BBC also reported that it’s unclear how effectively the existing vaccine will provide protection. The vaccine is currently about 75 to 80 percent effective at preventing mpox infection.
Speaking of public health, a study published last Monday in the Journal of the American Medical Association found that between 2017 and 2024 the proportion of newborns who didn’t receive a vitamin K injection increased by nearly 80 percent. The number of newborns not getting the shot went from roughly 3 percent to more than 5 percent.
Vitamin K is necessary for blood clotting, but newborns have naturally low levels of the nutrient. Skipping the injection means up to one in every 60 babies are at risk of developing vitamin K deficiency bleeding. It can lead to permanent brain damage or even death, according to SciAm’s reporting on the research. Since the 1960s the American Academy of Pediatrics has recommended that babies receive a vitamin K injection at birth to reduce this risk. The injection has been seen as a neonatal success story.
Research into vitamin K refusal by Jaspreet Loyal, a doctor at the Yale New Haven Children’s Hospital who was not involved in the study, offered some insight as to why some parents may refuse the shot. She told SciAm her research found these parents may have the misperception that the risks are greater than the benefits or may want to go a more “natural” route when it comes to child-rearing. Some online influencers have suggested giving babies oral vitamin K instead of the injection, but the oral version is not as readily absorbed, and the shot bears negligible risks.
And now on to a hobbit mystery. At the center of the story lies an early human relative called Homo floresiensis. The species’s tiny stature led scientists to nickname them hobbits, after the fictional beings we all know and love. They even lived in their own version of a hobbit hole, taking up residence for some 140,000 years in a cave called Liang Bua on an island in Indonesia. But around 50,000 years ago they simply vanished.
Research published last Monday in the journal Nature Communications Earth & Environment may finally shed some light on why. The scientists reconstructed past climate and rainfall conditions using stalagmites from the cave. This led the researchers to conclude that around the time Homo floresiensis disappeared, a severe drought took hold, causing summer rainfall to decline and riverbeds to become seasonally dry. The researchers also conducted analysis on fossilized teeth from pygmy elephants, which were an important food source for the hobbits. They found that these creatures relied on river water to survive. As the climate became drier the number of pygmy elephants declined and the hobbits were left with less to eat. No second breakfasts, no elevenses, no luncheons or afternoon teas. The scientists concluded that the diminishing resources likely forced the hobbits to abandon Liang Bua.
What happened after the hobbits decamped from the cave is still shrouded in mystery. But Mike Gagan, lead author of the study and an honorary professor at the University of Wollongong in Australia, said in a statement, “It’s possible that as the hobbits moved in search of water and prey, they encountered modern humans. In that sense, climate change may have set the stage for their final disappearance.”
That’s all for today’s episode. Tune in on Wednesday, when we talk with SciAm senior multimedia editor Kelso Harper, who spent the summer stalking orcas in the Pacific Northwest.
Science Quickly is produced by me, Kendra Pierre-Louis, along with Fonda Mwangi and Jeff DelViscio. This episode was edited by Alex Sugiura. Shayna Posses and Aaron Shattuck fact-check our show. Our theme music was composed by Dominic Smith. Subscribe to Scientific American for more up-to-date and in-depth science news.
For Scientific American, this is Kendra Pierre-Louis. Have a great week!
