Why does America want Greenland?; Mystery of dark DNA; Ozempic weight rebound

0:00It's not just something you made, it's the privilege that you get to work with your hands. It's building something that serves a purpose. Proof that you have the grit to keep going. At Timberland, we understand you take your craft seriously. And we do too. Which is why our products are built to the highest quality. We put in the work so you can perfect yours. With purpose in every detail and crafted with intention. Timberland. Built on craft. Visit Timberland.com to shop. Greenland is in the news again because the White House this week reiterated that President Trump wants to acquire the country, the White House said that utilising the US military is always an option.

0:40In the same statement, the White House said that acquiring Greenland is a national security priority needed to deter adversaries in the Arctic. We're going to look at some of the reasons the US is so interested in Greenland. Yeah, that includes its rare minerals, oil, and even the potential to build experimental cities on the island. Also this week, we hear about what a new study is finally telling us about the role of so-called junk DNA. That's the vast amount of DNA in our genomes that doesn't appear to do anything. We know that only 1 % of the DNA in our cells actually codes for proteins. What does rest do?

1:13Does it matter? And we discuss new findings around one of the biggest questions about weight loss drugs. What actually happens when you stop taking them? People do eventually come off it. So the researchers wanted to understand what happens when you come off them and if you do gain weight, how quickly does it happen? And spoiler, it's probably not great.

1:34Welcome to The World, The Universe and Us from New Scientist. I'm Dr Rowan Hooper. And I'm Dr Penny Sarche. So let's start with Greenland. Back in 2025, President Trump said the US needed Greenland for economic security. But this year, the emphasis has now seemed to shift to national security, even though there is already a US military base on Greenland. Yeah, and that base is quite closely involved in things like missile detection, and it's quite integrated into the US response. So today, yeah, we want to start by looking at national security and economic security with regards to Greenland as they relate to the US, but also the bigger picture on Greenland and the stuff we normally talk about, sea level rise, ice melt, the climate crisis.

2:18So to start, I spoke with Anna Merrill. She's a professor of sustainability and planning at Arlborg University in Denmark, but she's also lived in Greenland for many years. And I asked her first, what's new about the change in emphasis from the US government? What is new is that the Arctic more broadly these years are becoming geopolitically significant and melting sea ice is opening up new shipping routes. And there's also a growing interest from other major powers, including Russia and China. So Greenland's strategic value is less about acquiring something new and more about maintaining influence and stability in a region that is changing very fast.

2:54so new shipping routes is a big deal and one of the things we often hear about greenland is rare earth elements and minerals that it contains or is assumed to contain but greenland is a big place and it's mostly unexplored so how do we know that it has all of these rare earths that we want yeah it's massive place um most of it's not been explored and so the estimates about all the stuff that it's got all the resources so that's iron iron ore copper zinc gold uranium but then there's all these rare earth elements. They're based on what we know about geology, shared geology in similar places like northern Canada and Norway, where we have already identified those.

3:35Okay, so that seems quite a sort of safe bet then. Yeah, and there's been there has been some exploration prospecting. The other thing is the infrastructure on Greenland is basically not there. There's no infrastructure. No, not really. Once you leave the town, you either have to fly or go by boat around the island. There are a few mines, but they're not ready for mass extraction. So you have to do prospecting to find viable places for mining. Then you have to build the mines, exploratory mines, and then a way to get all that ore out. So it's very expensive. And the same with offshore exploration and fossil fuel extraction.

4:12And there you've got icebergs floating around to deal with as well. I also spoke with Ruth Mottram about all this. She's a climate scientist at the Danish Meteorological Institute. A big part of her work is concerned with monitoring and modelling all the ice on Greenland, although she's in Antarctica at the moment, which is where she sent this from. But the idea that we're going to be producing large amounts of minerals and petroleum products from Greenland in the near future is definitely not very likely. The logistical challenges around exploiting minerals and other resources in Greenland are really quite staggering.

4:50There's no roads on the island, so outside of the towns you need to take a boat or fly. The glaciers, of course, are melting. We're seeing increasing amounts of meltwater coming out of the ice sheet. We're seeing retreats of the glaciers. We're seeing a lot of iceberg carving, but they are still covering the vast majority of the island. It's going to take many, many decades, centuries to uncover a lot of the sort of what we think of as untapped potential of Greenland. and in the meantime the logistics of getting around are very challenging. On top of the melting glaciers we also have to contend with sea ice so the sea ice still forms every winter.

5:26The season is getting shorter especially in southern Greenland but that's also a big challenge for navigation around the shores of Greenland so when we talk about the sort of potential to develop these things in Greenland it's a long-term project it's not going to happen overnight. Good line from Antarctica wasn't it? Is that the first time we've had someone speak to us from Antarctica no I don't know I have to check yeah maybe so yeah as she said not gonna happen overnight um for the minerals it's not just that you have to dig them up you have to process them and that turns out to be much harder than I thought um rare earth elements are not just found in nuggets they're all in minerals very hard to extract and China is currently um leading the world in in doing that processing them um and here's Anna Merrill again and when it comes to the rare earth elements.

6:15Extraction is only a part of the story. Processing is technically complex, and at the moment, much of that expertise sits in China. So whether Greenland can deliver economic returns is not just a geological question. It depends on which minerals are involved in the global market conditions, commodity prices, environmental regulation, local politic, and who is willing to carry out the financial and environmental risk. For the US, this makes It's been then much more of a long-term strategic interest and a source of quick economic gains. So even if it was decided that Greenland was going to develop mining infrastructure and extract all of that stuff, we've got no processing capability really.

6:58It's certainly not in Europe and not really in the US. It would need to be really ramped up massively. So yeah, it's a long-term gain to get those minerals out. Right, so there's lots that needs to happen before we have rare earths flowing out of Greenland. I guess the idea is to use these in things like technology. We need rare earth minerals. Especially green tech, batteries, turbines, yeah. And for the situation to actually get there, you need this ice melt as a result of climate change. Can we get into some of the figures then on the scale of what we're talking about there? What's expected with Greenland ice melt?

7:33Yeah, brace yourself for some of the figures. For this, I spoke with Martin Stendhal. He's also a climate scientist at the Danish Meteorological Institute. He runs this thing called Polar Portal, which monitors Greenland ice, and here he is. During the hydrological year 2024-25, which is 1st of September 2024 to 31st of August 2025, the ice sheet has lost about 105 gigatons, that is 105 milliard tons, or 105 cubic kilometers of ice. This is less than the average over the period 2002 to 2025 for which we have data available, so even a good year is a bad year. In fact, 2024-25 is the 29th year in a row with net ice loss.

8:22The cumulative mass loss over the mentioned period 2002 to 2025 amounts to 5 ,500 gigatons. this mass loss alone has contributed about 1.5 cm to global sea level rise. These numbers have been corroborated by model studies. The 5 ,500 cubic kilometers may not sound much compared to the overall volume of the green ice sheet, which is about 2.9 million cubic kilometers. But with the disappearance of ice, the surface of the ice sheet lowers, so the temperature rises further and even more ice melts. In addition, the discharge of icebergs will also increase. By 2100, the Greenland ice sheet is projected to contribute between 8 and 27 cm to global sea level rise, according to the IPCC special report on the ocean and triosphere in a changing climate.

9:16If these processes continue, we may be approaching a tipping point, or point of no return, with all or most of the ice sheet melting. However, over a period of thousands of years, if all ice melted, sea level would rise about seven and a half metres. Yeah, so there's a lot, a lot of ice. Even in a good year, it's bad. I'm trying to get my head around all of those big numbers there. How much of a sea level rise did you say? Already one and a half centimetres. Wow. Yeah. So, yeah, it's a big problem that's already happening. But there's another thing I wanted to mention about Greenland. and around the motives that the US has.

9:55There's a startup called Praxis, and their aim is to build what's called a network city. It's sometimes called a freedom city. It was called that by President Trump during his campaign. So this is a private city, non-democratic. It's ruled by a technological government, basically. What could go wrong? The idea is backed by Peter Thiel, the PayPal billionaire. it's also backed by sam altman founder of open ai praxis already has hundreds of millions of dollars of seed funding and the founder went to greenland in 2023 to try and buy it he didn't succeed in that but he said okay i won't buy the whole thing but i want to buy a big chunk of it so that he could build a prototype terminus he called it dare i ask what is a prototype terminus i'm not going to like this am i you're not terminus is the name that um elon musk wants to call his projected city on Mars.

10:51Right, of course, yes. So the idea is, well, let's have a prototype of Terminus and we can build it somewhere like Greenland. Is this all sort of pie in the sky, far-fetched? I mean, I think it is a bit far-fetched, but it doesn't stop people kind of trying to make it happen, like actively and at quite high levels. People do want to do it. The US ambassador to Denmark is an investor in Peter Thiel's venture firm called Founders Fund, President Trump has explicitly said he wants his ambassador to negotiate a deal to buy Greenland. So I asked Anna Merrill also again about this, and here's what she said.

11:28I've seen some of these ideas about so-called freedom cities or network cities in Greenland, but they remain, as I see it, highly speculative. From a governance perspective, they also raise serious concerns about sovereignty, regulation and social responsibility. Greenland is not an empty space waiting to be experimented on. It has communities, democratic institutions and a strong sense of self-determination. And any such proposals as the ones in relation to freedom cities and network cities would have to align with Greenlandic law and values and long-term societal goals. And so far, these ideas seem quite disconnected from reality.

12:08Greenland's not an empty space waiting to be colonized and taken over. Worth remembering, yeah. My day kicks off with a refreshing Celsius energy drink, then straight to the gym. Pre-K pickup, back home to meal prep. Time for my fire station shift. One more Celsius, got to keep the lights on. When the three alarm hits, I'm ready. Celsius. Live, fit, go. Grab a cold refreshing Celsius at your local retailer or locate now at Celsius.com.

12:38Now you may have heard the term dark DNA or junk DNA. These are large swathes of genetic material we have in our bodies, but they don't seem to have an obvious function. For decades, we've wondered, does this stuff actually do anything? And a team in New Zealand has been doing a unique experiment. They've been making hybrid human plant cells to find out. That's right, they're making human cells containing massive chunks of plant DNA. Michael LaPage has this exclusive story and he's here to tell us about it. Michael, what's going on? So I think we probably should start at the beginning with this one.

13:12So if we go back to when DNA or the structure of DNA was first discovered, we assumed then that it would all code for proteins because that's what DNA was thought to be for. But then it turned out a lot of it doesn't code for proteins. In fact, today we know that only 1 % of the DNA in our cells actually codes for proteins. So there's been this question of what does the rest do? Does it matter? Now, it's always been clear that some of the DNA that doesn't code for proteins is important. But the question is, is it 5 % or is it 95 %? obviously that's a huge difference. Okay, so we've got a few percentages here, but the basics is that 99 % of the human genome is non-coding, as in it doesn't make proteins.

13:51And what we want to know is of that 99%, is it almost entirely junk or is actually a decent proportion, maybe even most of it, useful in some way? Yeah. And so we used to think it was a tiny proportion, as low as 5%, because when you look at how much of the genome is conserved by evolution, it's sort of 5 % but then back in 2012 we had this big project called ENCODE and what they did is they studied what activity was happening with this DNA so for instance is a bit of DNA sort of copied into RNA at any point and if it is then they say that bit of DNA is active. Because that's the intermediate stage of reading a gene right is to turn it into RNA and then make protein.

14:34Exactly you want to make a protein you start by making RNA but some RNAs have their own functions but But anyway, so ENCODE found that 80 % of the genome is active in some way and sort of turned into RNA or something like this. Now, that's not controversial. But then what they did next is they said, well, because it's active, it's functional and it therefore has an important purpose. And therefore, 80 % of our genome is in junk DNA. If that's true, that means that there's this vast part of our DNA that's doing something important, but we don't understand what it is. We've got no idea. And that's why we started calling it dark DNA rather than to sort of assume and denigrate it by calling it junk.

15:13Yeah. So it's a sort of comparison with the physics. So we know with the universe, most of it consists of dark matter, but we don't know what it is. And so people started using this term dark DNA. Petition to start calling it junk matter. Sorry. Anyway, so this idea of dark DNA, it's really controversial because it all hinges on this definition of, you know, active meaning functional. So critics have been co-pointed out that, you know, there's actually lots of noise in biological systems. And so what this activity that might be seeing, it might be noise rather than actual functional or something useful happening.

15:53And in particular, there was a biologist called Sean Eddy, and he proposed what he called the Random Genome Project. So this is the idea. If you want to prove that something is noise or not, you put random DNA into the human genome and you say, is it active or not? And if it is active, then it's showing that there's a lot of noise in the system. Now, the trouble with doing this is to synthesize DNA, it's still really expensive. So people, there have been a few small attempts at doing this, but they've used like 100 ,000 base pairs of DNA, which is tiny and it's not really been very clear. but this is where we get to the plant hybrid the sort of human sort of plant hybrid cells loving this yeah yeah bring in the plants um so essentially are we getting around this issue of we're not having to build it if we're using plants they've already made their own dna and we're we're then putting it into human cells exactly what happens so in fact the team that did this other they didn't create these uh human plant hybrid cells themselves this was done by a japanese team who are studying chromosomes and the Japanese team put 35 million base pairs of plant DNA into some sort of human cells these are just growing and you know in a dish it's not not trying to create a sort of you know actual sort of swamp thing no but anyway so this is effectively the biggest random genome project that anyone has has tried yet or at least there was these researchers as researcher called Brett Aidy at the University of Auckland in New Zealand realized this is effectively a random genome project that they've done.

17:19Right, because it's the idea that plants are so distantly related to us that their non-coding DNA might as well be random. Exactly. There's just no way it would be functional enough. So we last shared a common answer to something like one and a half billion years ago. And pretty much every single letter of DNA in those plant genomes has mutated several times since. So it's randomised. OK, so they dumped all this plant DNA into the human cells. What have they found? Well, so basically they compared the activity levels of the non-coding plant DNA with the non-coding human DNA. And they found that the activity level was nearly the same.

17:58So that's almost as much as the random plant DNA was being turned into RNA as with the human sort of DNA was being turned into RNA. So basically, this is showing that there's a huge amount of noise in the system. And what ENCODE was saying, this is activity, therefore it's functional. Actually, no, that's activity and it's mostly noise and only a tiny bit of it's actually functional. And that means, of course, that most of our genome is junk. That, you know, that sort of so-called dark DNA is nothing mysterious. It's just a whole lot of rubbish sitting in our genomes. So why is there so much noise, though?

18:35because you know all this junk dna is it really that inefficient to have it there the big question is always if it's that bad evolution would have got rid of it yeah there's so there are two ways of looking at this uh the first of which is we're not very highly evolved so if you compare us to viruses and bacteria but what what i mean is for evolution to do stuff it's all about it's a numbers game so with sort of bacterial viruses that you've got billions of individuals and they've been selected for over in fact it's trillions trillions of generations now if you look at humans since humans first evolved like our populations have usually been in sort of thousands they've only been something like 10 000 generations of modern humans since we evolved there's really not much chance for evolution to sort of hone our genome and get rid of the junk and make us more efficient.

19:28That's amazing, 10 ,000 generations. Yeah, that wasn't what I was frowning at because I don't really believe that that's not time. You know, there was junk DNA before 10 ,000 years ago in our ancestors, even in the ancestors of mammals. But there are things that, it made me think of another kind of plant, which is the conifers and gymnosperms, because they've got these huge genomes. It's thought that one of the reasons they're not that successful anymore they've basically entirely lost out to flowering plants is because they haven't been able to shrink the genomes down they they don't reproduce enough they aren't they aren't mutating as quickly and they can't actually get rid of it so it we know that this kind of thing can be an evolutionary cost but and that you just have to live with basically yeah the lungfish too are they they're the animals with the largest genomes and we think they've got their genomes are 30 times larger than ours and we think that's just because they're very bad at getting rid of that junk DNA.

20:25It's just accumulating in their cells and sort of they've been carrying it around for millions of years, hundreds of millions of years. As Pony was saying, if they didn't have it, they might be much more successful. They might be running this podcast. Yes. Well, they sort of are in a way because they're kind of our ancestors. So yeah, some of them managed it. That's a nice way to think about it. Well, so I just still don't think it's that detrimental to be carrying around this stuff hasn't slowed me down. Or this non-coding DNA. You're all right with it. Well, OK, but I bet if we sort of created a Roan Hooper Mark II minus all the junk DNA, I bet that Roan Hooper would outcompete you and do much better.

21:09You're going to give some tech guru an idea now to actually try and clean out the genome. Well, it's not an experiment we've done with any animal yet, but I'm sure it will be done in the future where we sort of get rid of a whole bunch of junk DNA and then sort of compare the success of... Sounds like the kind of thing Craig Benter or someone might be doing that. Yeah, I mean, there have been some small attempts at it. I mean, you could do it with a fast-breeding insect or something. Yeah, absolutely. Yeah, that's a great idea. But is there any way from an evolutionary perspective that this noise might be useful?

21:41Yeah, absolutely. I was talking about there being two ways. this is the the other way so if if you think about it from a long-term evolutionary perspective if we've got random bits of dna being turned into rna and maybe sometimes even been turned into protein sometimes that protein might turn out to be useful and then evolution can grab onto that and sort of select for it and we can end up with a whole new gene coming out of junk and in fact we know that humans have several of these sort of they call de novo genes so it does happen really Of course, that doesn't mean all that junk is useful, but it means it can sometimes.

22:15You can sort of find something useful inside that junk. I guess kind of DNA needs to be a bit accidental and leaky and noisy because that's probably how it got the role that it has in all of life in the first place. That's the field of the evolution of evolvability. Yes. It has to be slightly imperfect to be more evolvable. and so just to get my head around this you know the the central dogma of molecular biology you've got your dna goes to an intermediary of rna and then protein all of this kind of noisy reading and making of rna it's not also then making accidental proteins as a result oh yeah no as i was saying so you couldn't get this of these de novo genes that evolved you know new proteins is that very rare or is that happening at the same sort of scale as the rna so this this noise is is is rarer so if we've got sort of you know important genes that are doing something really important they're going to be active much more active much more of the RNA made much more of the protein made than this sort of this random noise but you know just occasionally some of that random noise might do something useful enough that it then gets selected for and then that will happen more often and start to become important.

23:25So obviously from a scientific point of view it's really important for us to understand what our genome is actually doing is there broader significance beyond that yeah i think it is i mean for starters the fact that most of our genome is junk is obviously it's hard i would say impossible to just square with the idea that we're sort of the product of some kind of design uh by some sort of intelligent being in other words i think uh to put it the other way around you know some people have been arguing that most of our dna isn't junk because they don't like the idea that we weren't designed as a religious aspect to it.

24:02But even if you're not superstitious, I think this tells us something about ourselves. We know we're not these sort of perfectly honed, perfect creations. We're sort of very much a work and process with lots of sort of rubbish. I mean, the human book of life turns out to be mostly gibberish, which is, you know, not what we really wanted to hear. But I think it's an important perspective to have as you come to the point where you're starting to think of, do we start to tweak with our children's genomes or not? That's sort of the perspective we need to have on our genome. It's not some sort of holy code that we can't tamper with.

24:39It's very much the opposite. We've got two diet stories this week. We're going to hear about why if you're overweight and taking drugs like a Zempic, you might need to be on those long term. But first, there's a finding that fibre helps with your sleep. Alexandra Thompson is here. Alex, fibre, it's got to be to do with our gut microbiome, right? Yes. So we knew there was a link between the gut microbiome and sleep. So studies have suggested that having a more diverse gut microbiome reduces the risk of sleep issues. And studies have also linked sort of unfavourable bacterial species in the gut to sort of sleep problems.

25:14But this is a big review of 53 observational studies with 9 ,000 participants between them. and perhaps unsurprisingly they found lower diversity is linked to sleep disorders they also pinpointed low levels of anti-inflammatory bacteria that's not good news but what I think is most interesting is they quite specifically pinpointed low levels of bacteria that produce a fatty acid called butyrates which is produced as a result of fermenting dietary fiber so with the caveat that more research is needed it might not be that outlandish to suggest in the years to come that eating fibre could help with sleep.

25:54So eating fibre might help sleep, but this is the old thing about causality, isn't it? We don't know whether if you have good sleep, you get better bacteria and that's what you're looking or if it goes the other way around. Yes. And that is really hard to disentangle because if someone isn't sleeping well, and that's an ongoing issue, they're going to be exhausted. They might not be motivated to make a nutritious meal with plenty of roughage from scratch and that has knock-on effects on the gut microbiome. But having said that there are some really interesting studies in mice where they have depleted the gut microbiome and that has subsequently led to sleep issues and they've even transferred those issues over to other mice via faecal microbiome transplants.

26:36So in people there is less sort of direct research but there have been studies where people have been given certain types of probiotics versus a placebo and they have self-reported reasonable improvements in sleep quality. So there is some signals of causality even if it's not conclusive. Okay but for anyone thinking oh right I just go and eat loads of fibre and it helped me sleep better there's we cannot say that yet and there are lots of good reasons to eat fibre for your diet but if you're thinking it's going to help you sleep better we can't say that yet. No, we can't say that yet. Like you said, fibre is increasingly being linked to improved immune function and lower inflammation.

27:16It's even been called nature's zempic. I would say it's a fairly low risk strategy, but we can't conclusively recommend anything. We do know, though, it's really well established that if you're eating a Western diet, you very probably aren't getting enough fibre. So it can't hurt, right? There's loads of other side benefits from fibre. And maybe the placebo effect will give you a good night's sleep. Possibly. I can't see there being many drawbacks. Most people are deficient in it anyway. Yeah. The other story we wanted to ask you about this week is this paper showing that people who stop taking weight loss drugs tend to regain the weight they lost within less than two years.