Why COP28 probably won’t keep the 1.5 degree dream alive

Nick Petrić Howe

Welcome back to the Nature Podcast, this time: with COP28 looming, is it too late to limit Climate Change to 1.5 degrees?

Shamini Bundell

...and some plasma-generating hairy fibers. I'm Shamini Bundell...

Nick Petrić Howe

...and I'm Nick Petric Howe.

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Nick Petrić Howe

The UN’s Climate Change Conference, COP28, is starting in a few days. World leaders, scientists and various movers and shakers in all things climate will descend on Dubai. To find out what to expect I’m joined by Jeff Tollefson, who covers climate change, here at Nature. Jeff, how’s it going?

Jeff Tollefson

Good. Good to be here, Nick.

Nick Petrić Howe

Well, thanks for joining me. Now, one of the big topics at this year's COP, COP28, is the goal of keeping warming under 1.5 degrees. This was a key target of the 2015 Paris Agreement to avoid the worst impacts of climate change. And this particular COP will mark the end of like the formal assessment of how it's going so far, you've written a feature about this topic. So, to start with, let me ask 8 years on from Paris, how big is this challenge?

Jeff Tollefson

Well, it's big and it gets bigger every year. The short story is that emissions are still rising and despite a lot of progress in terms of, you know, renewable energy deployments and costs coming down for clean energy technology, and lots of commitments, the simple fact is that emissions are at record levels. And we don't really have an easy pathway to cut emissions over the next, you know, 12 years or so in order to easily meet that 1.5 degree target, without extracting large amounts of CO₂. later in the century.

Nick Petrić Howe

And from your feature, it kind of seems like the language is changing a little bit from can we meet 1.5, but exactly what the overshoots will be. So can you tell me a little bit about that, what are scientists sort of predicting now as we go forward into the future?

Jeff Tollefson

Well, there are a lot of projections out there. And all of them rely on a lot of assumptions. So, you have to take all of this with a grain of salt. But in general, the people who kind of track energy and climate policies and emissions estimate that, you know, if the world were to kind of maintain its current level of momentum, you'd wind up somewhere around 2.5 degrees of warming by the end of the century. You know, and that does represent progress a decade ago, we were talking about, you know, warming up well over 3 degrees. So business, as usual, has changed. That's the good news. But there's still a big yawning gap between 2.5, which is, you know, our best estimate for where we're headed and 1.5 or 2.

Nick Petrić Howe

Now, with this sort of overshoot idea in mind, this relies on a lot of assumptions that will be able to pull a lot of CO₂ out the atmosphere. Where is the science on that? And how likely is it that we're going to be able to pull a lot of CO₂ out of the atmosphere later this century?

Jeff Tollefson

Well, that is the trillion-dollar question. Nobody really knows. There's a lot of R&D underway into various methodologies for extracting carbon, you can do it with industrial processes, perhaps you might be able to do it with nature-based policies, extracting CO₂ out of the atmosphere and into the ocean, planting forests. Some of these are pretty basic things that we know how to do. But in a lot of cases, the science just isn't there. In terms of the you know, both how you accomplish these things at large scale and whether there might be unintended knock on effects that occur when you deploy these things at large scale. So the real challenge here is that we've got a situation where the international political agreement that people are following is kind of guiding us in a way as to depend on negative emissions on extracting CO₂ out of the atmosphere later in the century. And we really don't have the technologies today that we know how to do that. So, there's a lot of need for R&D, for investments and for you know, government policies that will start to ramp things up in case we do need these technologies in the years to come. That said, one thing is clear. The first thing that the world needs to do is stop emitting. And then we can think about how to run the climate and reverse and extract CO₂.

Nick Petrić Howe

And so looking forward to COP28, which is starting in a few days at the time of recording, what do we need to, I guess, try and keep this dream of 1.5 alive? What do we need to see coming out of this COP?

Jeff Tollefson

Well, you know, this is the annual question. I mean, really, what we need is more action at the national level and less talk at meetings like these. That said, these meetings do serve a very real purpose in terms of kind of setting international agendas and holding countries to account. So in theory, you know, countries have already committed to do what needs to be done under Paris. But the reality is that everybody knew in 2015, that the commitments that had been made, you know, we're falling short of the goals that were laid out in that agreement. And so, what was done to account for that fact, was to set up this kind of global stock take process. And the basic idea is that every five years, governments have to kind of look squarely at the numbers do an assessment of their collective progress toward the Paris goals. And, in theory, the results of that are–are supposed to inform the next round of commitments. How that is going to work, it's still a little bit unclear what exactly needs to come out of COP28, it's still a little bit unclear, but people are talking about some landing spaces, there may be some new language, kind of setting a path toward 1.5. Again, laying out what needs to be done and then calling on countries to double down on their efforts. You know, there are other things going on in the sidelines, which are focused on setting a global agreement on phasing out fossil fuels, and ramping up climate finance. So there are many levers that you can attack this problem through, financed fossil fuel commitments, you know, renewable energy commitments, all of those things are going to be in play at COP28, we'll have to see how things play out then.

Jeff Tollefson

And speaking of the sort of like language of agreements, there has been a lot of talk about a sort of phase down of fossil fuels to meet our climate goals, we obviously need to stop using so many fossil fuels. And this year, the hosts are the United Arab Emirates, the UAE. And the UAE is a big fossil fuel exporter, as are many other countries, including the US. But are there any concerns here that there may be, you know, some sense of conflict of interest?

Jeff Tollefson

Well certainly. And there have been accusations raised that the UAE has used its presidency of the COP to actually push fossil fuels. I mean, you know, if you step back, there's a dynamic within these negotiations that was always there. And the major fossil fuel producers, including the UAE, and also the United States, Russia, a lot of Gulf Coast countries, all have a kind of collective interest in maintaining fossil fuel production. And this has always been a problem. One can expect them to argue against stringent language on a fossil fuel phase out. And so this is going to be the kind of the dynamic at COP28 on this key point. I mean I think we should note that this is like, you know, one of the most fundamental points, the science is perfectly clear, the climate will keep warming as long as we're pumping emissions into the atmosphere. And that means the climate will keep warming as long as we're producing and using fossil fuels, at least without capturing those emissions and doing something else with them, like pumping them underground.

Nick Petrić Howe

And speaking of emissions, the leaders of the two biggest carbon emitters, China and the US are not in attendance this year. Does their absence puts a bit of a dampener on people's expectations from this COP?

Jeff Tollefson

I would imagine it does. But we'll kind of have to see how things play out. You know, at the same time, there was this kind of 'New Deal' announced between the US and China, which I think a lot of people in the international sphere think is a big deal. One might ask, why? You know, the US and China have worked together on these kinds of things in the past, and we are where we are, which is not where we need to be. So does it make a difference? Well, you know, these things are hard to measure. But in terms of the way the negotiations work, the kind of the politics inside the COP, you know, it is important to have the two world's largest emitters on board and talking to each other, which hasn't been the case in recent years due to disagreements on multiple fronts. So you know, the fact that they're not coming is not the best of news. The fact that they're working together is good news. Make of that what you will.

Nick Petrić Howe

And so how are you feeling going into this years COP? Optimistic, pessimistic or somewhere in between?

Jeff Tollefson

Certainly not optimistic. That said, it's becoming increasingly clear that the transition that we need is happening. The economic transition toward clean energies seems to be unstoppable at this point and given time, that will change the politics, and that will drive new policies and new commitments. The problem is that we don't have a lot of time. And that's where the challenges come.

Nick Petrić Howe

A tall order, indeed. Well, Jeff, thank you so much for joining me.

Jeff Tollefson

You're welcome.

Nick Petrić Howe

That was Jeff Tollefson. For more on Nature’s climate coverage, check out the show notes for some links.

Shamini Bundell

Coming up, an easier way to make plasma. Right now, though, it's the Research Highlights read by Dan Fox.

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Dan Fox

Crows and parrots may be known for their cleverness. But researchers have found wild falcons are no bird brains either. Researchers tested 15 striated caracaras, a species of falcon for their ability to find new solutions to a problem. The birds were faced with eight tasks to solve for a food reward. Each with a different solution such as sliding a door or pulling a wire. The team found that the birds worked out solutions at a rate as high as one per 1.6 minutes during their first attempt at the tasks and during subsequent attempts solved more tasks and completed them faster. Eventually, one bird was able to complete all eight in under five minutes. Nearly all characters completed all the tasks, including ones that had stumped more than 50% of Goffin's cockatoos – birds renowned for their problem-solving. The authors say these falcons are a promising model for examining bird intelligence in the wild. The early bird catches that research in Current Biology.

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Dan Fox

Smoke from the record-breaking 2020 wildfires in California contributed to cloudier days in Europe. Researchers used remote-sensing technology to monitor the distribution of fine particles in the atmosphere above Cyprus in late-October 2020. They found that smoke particles originating from wildfires burning in California earlier that month reached the eastern Mediterranean in 8-9 days. Above Cyprus, these particles triggered the formation of extended layers of long, wispy white cirrus clouds. The findings could have implications for the climate, given the clouds have a key role in regulating the amount of solar radiation trapped near the Earth's surface, and climate change means the frequency of wildfires is rising. Read that research in full, in Atmospheric Chemistry and Physics.

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Shamini Bundell

Finally, it is Briefing Chat time here on the Nature Podcast, where we discuss some stories that have come up in the Nature Briefing. So, Nick, what's your pick for this week?

Nick Petrić Howe

Well, I've been reading in Nature about the most powerful cosmic ray that's been spotted for about 30 years. And it has scientists kind of puzzled.

Shamini Bundell

Ooh, well, we love puzzling signals from space here on the Nature Podcast. What is so puzzling about this particular cosmic ray?

Nick Petrić Howe

Yeah, so this particular cosmic ray is very powerful. And that's what is puzzling scientists because they don't really know how it's created or where it's coming from. And I should say, as well cosmic rays are kind of confusingly named, they're not really rays at all. They're particles, so they're often protons. But they're these particles that sort of zip through space, at sort of a incredible speed, almost speed of light, often, and in this case, this particular particle that was spotted has an incredible amount of energy. So, it had the amount of energy, which is 214 exa-electronvolts, which is a unit of measurement which is like 10 to the 18th. And one, yeah, it's a lot of energy.

Shamini Bundell

Okay. I was going to say I don't know that one, the exa, I know, like giga, mega. But yeah, that's the 10 to the 18 is a pretty high one there.

Nick Petrić Howe

Yeah, it's a pretty high one. So to put that into some amount of context, 1 exa-electronvolt is 1 million times what we can make with the most powerful particle accelerator. So–

Shamini Bundell

–oh–

Nick Petrić Howe

–the reason you probably haven't come across it is it's not something we get a whole lot. The other example of something that was in the exa-electronvolt range was the cosmic ray that was seen back in 1991, nicknamed the 'Oh-My-God' particle, because it was around 320 exa-electronvolts. So even more powerful than this one that we've just seen now.

Shamini Bundell

And so cosmic rays in general, do we have any idea where any of them have come from? Like do we know that they're all even the same thing? Is it just this one that's sort of doesn't fit?

Nick Petrić Howe

So, we don't exactly know where cosmic rays are coming from, we've got some ideas. Supernovas seem like quite a good candidate. But also cosmic rays seem to come from some regions of space more so than others. So there could be something special going on there. But the particularly confusing thing about this cosmic ray – which has been named 'Amaterasu', after the Japanese Shinto goddess of the Sun – is because it is so high energy, it shouldn't really be affected very much by magnetic fields. So it should travel through space in pretty much a straight line. And so therefore, you should be quite easily able to see where it's come from. But when researchers looked at this cosmic ray, and tried to trace its path backwards, it seemed to be coming from just a void in space, which is kind of confusing. If it's coming from a black hole, or a quasar or something, you might be like, oh, well, that's what's creating it. But in this case, it seems to have come from nowhere at all.

Shamini Bundell

A mysterious void with mysterious rays. So presumably, despite the mystery and the puzzle, the scientists have their various theories.

Nick Petrić Howe

They do have their theories, but the theories themselves are quite interesting. So I'll start with the more dull theory. First, the dull theory is perhaps there is some sort of mistake or misunderstanding in how we understand magnetic fields and their interaction with these cosmic rays, it could be the course that we've traced back is leading us to the wrong place, not actually the source of this cosmic ray. The more interesting theory, though, is that this has been created by some sort of novel physics. And we know on the Nature Podcast that physicists love a bit of new physics. So that is certainly more intriguing. But time will tell exactly what that would be.

Shamini Bundell

Oh, so the theory is just, new something we don't understand yet. It's not even it's not even an actual explanation. It's just we don't have the–the understanding yet to be able to explain this.

Nick Petrić Howe

Yeah, because we don't know how anything with this much energy could be created? How it's traveling so far? And you know, if it's coming from a void? What's creating it in this void? So there's a lot of big questions to be had about this. And the other thing is that as I say, there's just been these two cosmic rays with this incredible amount of energy this 'Oh-My-God' particle now this 'Amaterasu' particle so they're quite rare. So it's hard to sort of study exactly where it is they're coming from. But hopefully, in the future, we'll see more. The Telescope Array that spotted this particular cosmic ray, are grading their equipment to be a lot more sensitive. So perhaps we can spot more like them in the future, because they do sort of fall across the Earth. But Earth is quite a big place, and they don't tend to have this high energy. So having more sensitive array will be quite useful in spotting cosmic rays in the future.

Shamini Bundell

Whichever theory’s right, it's quite interesting that it just does highlight what we don't know, in this case about whether it's space magnetism, weird rays, either way, yeah, more space mysteries incoming on the podcast, for sure. Mine is not a space mystery for you today. I've also got a story today that's from a Nature paper. And I've been making a video on this. So that's why I've been already digging into this particular one. And it's about a new way of making plasma. So the state of matter known as plasma.

Nick Petrić Howe

Amazing, new ways to make plasma sounds incredible. Just so we're on the same page, though, what what is plasma? When we're referring to it, you talked about like a different state of matter. What is it when something is plasma?

Shamini Bundell

Plasma is both weirdly alien and kind of really common in that on the one hand, plasma is when matter isn't a solid, liquid or gas, it can be a plasma, which is basically it's kind of like a soup of charged particles. And on the one hand, this can happen in really exotic places like lightning strikes, or like, in the Sun. But on the other hand, it can also be harnessed for plasma TVs, and like neon lights and things which have plasma inside them.

Nick Petrić Howe

Okay, so it's got a lot of uses, then I guess. So, why are researchers interested in finding sort of a new way to make it? What's wrong with the old methods?

Shamini Bundell

Yeah, so in a way plasma, as it does exist in tubeless. And stuff, it's not that hard to make. What you do is you get a gas, a neutral gas, and you apply or this is one where you can apply a really big voltage across it. And if you get a big enough voltage, the electrons detach from the atoms in the gas and then you've got electrons and you've got ions, and then you've got all these charged particles sort of moving around high-energy with this current flowing across this voltage gap between two plates, say or two tips of some sort of conducting material. And all of that movement basically emits heat and light. And in–and–depending on the conditions, that can be some really extreme light and heat. And that's the kind of use that would be like a plasma cutter, like plasma arc welding, where they make this little arc of plasma inside the machine and then use that heat, that extreme heat. And that's what this particular research is on finding a better way to make extreme heat. And what the differences with sort of all these uses, and sort of methods that have come before, is what they wanted to do, and have been able to do is create this really stable and uniform plasma. So rather than what's called an arc, so think like a lightning strike–

Nick Petrić Howe

–mm hmm, yeah–

Shamini Bundell

–sort of crossing that gap where it's kind of jumpy. It's not very stable, and it's only kind of between two points. What they want is a sort of a volume of gas that is all this plasma, and is all of equal temperature. And you can use that in science experiments, in particular, looking at high temperature materials, certain materials that are made at really high temperatures. And there's also the actual sort of manufacture of those high temperature materials as well. This is exactly the kind of thing that that would be really useful for.

Nick Petrić Howe

So, how have they managed then to get this sort of more stable plasma?

Shamini Bundell

So, hairy blocks is the answer. Excitingly, they've got– they've used– hairy blocks. Yeah, no, it's– it's true. Watch my video, you will see hairy blocks in action. Its basically instead of using, say tungsten tips, they use these carbon fiber blocks that are hairy, they look like–they looked hairy–it's all these little carbon fiber, fibers, I suppose. And the reason it works is that each of the little hairs over this sort of flat surface acts as an individual tip, to have this voltage build up and this arc, go across from one side to the other. And because you've got so many of them close together, they all just sort of merge together and it becomes this like, all of the gas in that space between those two hairy plates, all turns into a plasma, and it's all mixing, it's all sort of the same temperature and light. And it's really bright so they have to wear sunglasses. I've got some video clips of the researchers looking very cool in their special sunglasses, special lab sunglasses that basically stop them going blind, well, staring into the blinding light. And it's incredibly hot. And then that is a much more useful way to, let's say, make a material, because you've now got like a little area in which you can heat up a volume of materials.

Nick Petrić Howe

And the way you described it is sounds very simple, just you know, throw some hairy blocks in but how straightforward–how straightforward would it be for people to use and maybe potentially put in their plasma cutters?

Shamini Bundell

Well, so I was speaking to the researchers. And you know, it sounds very high tech. And like these kind of plasma experiments, when people are doing experiments with these kinds of like, really high temperatures, like hotter than the surface of the Sun type temperatures. A lot of the work on this is done in like, there's just a few specialists labs, like physics labs around the world, and like you need all this special kit. But actually, the researchers say, hey, you know what, this is really simple. All of the components that we've used, are relatively easy to access. And they're really excited that actually any physics lab could recreate their setup, and have access to this sort of super high temperature plasma to do experiments on and yeah, they say it really opens the door for a lot more of this kind of work to be done in a lot easier way.

Nick Petrić Howe

But yeah, that's in a lab setting. What about potential applications does this more stable form of plasma lend itself to any other sort of applications that people could use?

Shamini Bundell

Yeah. So again, the researchers reckon they think their method is great, they think it could replace current manufacturing methods that are used to produce certain high temperature materials. The example that they gave was jet engine, turbine blades, where they're going to be spinning around around, they're gonna be subject to these extreme heats. And you need a material that isn't going to kind of like melt and warp and sort of stretch as it's spinning and being heated. And therefore, what they use is these materials that are made, that are created at these high temperatures. And that was an example of something that can potentially be made with this method.

Nick Petrić Howe

Well, it certainly sounds like it opens up a lot of potential. Thanks, Shamini. But I think that's all we've got time for on this week's Briefing. Listeners, if you want to know more about any of the stories we've discussed there'll be links to them in the show notes. Along with a link to Shamini's video if you fancy seeing some plasma production in action.

Shamini Bundell

That is not all from the Nature Podcast this week though, because keep an eye on your podcast feed and there's going to be another bit of podcast goodness coming up tomorrow- we've got a special one off episode for you.

Nick Petrić Howe

But for now, if you want to keep in touch with us, you can. We're on X, @NaturePodcast, or you can email us, podcast@nature.com I'm Nick Petric Howe...

Shamini Bundell

... and i'm Shamini Bundell. Thanks for listening.