- 1 day ago
Category
📺
TVTranscript
00:01What can rocks from the past tell us about the world today?
00:05Why are we so resistant to change?
00:08And what can we do to challenge the status quo?
00:11And how do invasive species threaten nature and our way of life?
00:15We'll be looking into all this and more on 10 Things to Know About.
00:19This week we're looking at carbon, the vital element that connects all life on Earth, our geological past and our climate.
00:36We all have an idea of what carbon is. It's in diamonds and in pencils, in coal and in fizzy drinks.
00:55And life as we know it would not exist without carbon.
00:59Carbon can exist as a solid, liquid or gas and it's an important part of DNA,
01:04the molecule that stores the genetic instructions for human life.
01:08So how does this element that is so central to our existence pose such a threat to our planet?
01:16I'm at the Otherworldly Landscape of the Byron to meet Michelle McKeown to discuss how carbon builds the very fabric of our world.
01:26Michelle, why is carbon so important to life?
01:29Carbon is an element and it's fundamental to all life on Earth.
01:33So me and you, Fergus, we're made up of carbon, so our plants and animals.
01:38And it also comes in an inorganic form as well, which you can find in soils, in rocks, in water and in our atmosphere as carbon dioxide and methane.
01:48For millions of years, nature has kept a delicate balance, removing just the right amount of carbon dioxide from the air through a process known as the carbon cycle.
01:58Freeze will take carbon dioxide in from the atmosphere and store it in the biomass of that tree.
02:04Also in oceans, we have dissolved bicarbonate. So that carbon then is being used up by marine organisms to form kind of their shells.
02:13And we're here in this stunning vista of the Byron, but what role does carbon play in the formation of the Byron?
02:21So this is actually an amazing carbon store that we're sitting on.
02:25So this is calcium carbonate. So it's inorganic carbon.
02:29And 340 million years ago, we would have actually been in a tropical ocean.
02:34Wow.
02:35Yes.
02:36Not today. It's really cold today.
02:37Not today. No, no.
02:38It was a long time ago.
02:40And there would have been coral and marine organisms sucking some of that carbon out of the ocean and actually storing it in the shells.
02:48And then when these organisms died, their shells would have sank to the bottom of the ocean and formed this kind of calcium carbonate mud.
02:57So under millions of years and through lots of different pressure, it would have created limestone.
03:03Now, what we're sitting on here today, these limestone pavements, they have unique kind of land forms of different shapes to them.
03:10So we have turlocks. We have cave systems here. We have our limestone pavement.
03:15Through rainwater and through groundwater, what's actually happening is there's a weak carbonic acid in that water.
03:24And it's slowly dissolving some of that ancient kind of carbon that we're sitting on in these rocks and actually brings it back out to the Atlantic Ocean.
03:32So it can then be used by other organisms to form their shells.
03:36And it's a nice example of this carbon cycle.
03:40Since the Earth's formation 4.5 billion years ago, carbon dioxide or CO2 levels have varied wildly, shaping our planet's climate and life itself.
04:01Early volcanoes filled the air with CO2 until the first plants formed absorbing CO2 and cooling the planet.
04:09Over the last 800,000 years, CO2 fluctuated with ice ages, rising and falling due to changes in the Earth's orbit.
04:17However, the Industrial Revolution has increased CO2 levels and changed our climate at the fastest rate ever recorded in human history.
04:26This is where humans have really played a role in accelerating climate change.
04:31Because what we've been doing is taking these old stores of carbon like our coal, our gas, our oil and burning them and emitting that carbon back into the atmosphere as carbon dioxide.
04:42Now, the greenhouse effect is important. We need it for life on Earth. The problem is that we as humans have accelerated the carbon cycle.
04:49We all know that we need to reduce the amount of fossil fuels that we use, but is that enough?
04:55But we also need to have a look at our landscape and how we're using it as well. Only 11% of our land cover is actually trees.
05:01Also, peatlands as well. Actually raising the water table would allow less of that carbon to be released back to the atmosphere.
05:08And the ocean is one of the biggest sinks of carbon dioxide. Is that right?
05:13Yeah, that's correct. Yeah. So being able to understand kind of this role that the ocean plays in that carbon cycle is incredibly essential.
05:21To explore how rising CO2 levels impact our oceans and shape Earth's climate, scientists are pushing the limits of marine exploration.
05:42Tom Crean is one of two research vessels run by the Marine Institute in Galway. And like the great man she's named after, is dedicated to taking to the high seas to discover more about our planet.
05:56She plays a major role in helping us to improve our understanding about the ocean current system of the Atlantic.
06:02I'm here to meet Audrey Morley, whose research is helping to tell the story of our oceans.
06:08I'm a paleo oceanographer, so I study the ocean and the ocean climate in the past.
06:15And I'm particularly interested in the AMOC, which stands for the Atlantic Meridional Overturning Circulation.
06:21The AMOC is a system of currents. It transports warm waters from the tropics to the high latitudes at the surface,
06:30and then cold water at the bottom of the oceans out of the Arctic into the southern latitudes.
06:36So you think of it as a conveyor belt. It is bringing heat to the high northern latitudes and cold waters back south into the south of the Atlantic.
06:45The heat that is transported to northern latitudes is why our weather and climate here in Ireland is so mild and wet.
06:53Because not only do we get heat, but we also get a lot of moisture with it.
06:57And why are scientists so interested in AMOC at the moment?
07:01There have been signs that AMOC might be decreasing and that could have really important consequences for our weather and climate here.
07:09Because even a small decrease in the amount of heat and moisture that we are getting to Ireland would change our climate significantly.
07:17Our winters would get colder, we would have more extreme climates, seasonality might change as well, we would have more extreme storms most likely.
07:26And then our infrastructure, economy and agriculture needs to cope with all of these changes, which is not a small thing.
07:32And some of those things are already kind of baked in, in terms of climate change, but actually if AMOC was to be put on top of that, then who knows?
07:38Yeah.
07:39Well, who knows? You're going to find out.
07:41That is one of the goals, yes, to find out what the impacts are so that we can prepare for them.
07:46Scientists have been monitoring the AMOC since the early 2000s, but the ocean circulation responds on much longer timescales.
07:56Aboard research vessels like the Tom Crean and Celtic Explorer, Audrey and her colleagues collect water samples and marine cores to investigate what was happening in our oceans and atmosphere thousands of years ago.
08:07Her last expedition was in 2023.
08:11To get the climate archive, we deploy two different types of equipments, one that's called a multi-core and it takes small cores of the very surface of the ocean floor.
08:23And then we deploy a gravity core that will take up to six meters of sediments from the chosen site.
08:30Back at her lab in the University of Galway, Audrey shows me one of the cores she collected from the seabed where deep Atlantic currents flow.
08:39On their path, they carry sediments with them.
08:42When the currents are very strong and the AMOC is strong, then the grain size that the currents are carrying is larger.
08:48OK.
08:49But when they're weaker, the sediment size will decrease as well.
08:53So if I take samples from this core and go back in time or down the core, I can measure changes in grain size and therefore infer changes in AMOC strengths.
09:04OK, very good. And can you tell how far back in time you're going according to the depth of the sediment?
09:10That is actually the first step. We need to know how old this core is.
09:14So in order to do that, I have to take samples at certain intervals throughout the core to radiocarbon-dade fossil material that is preserved in the mud.
09:23And these fossils that you're looking at, what creatures are they from the past?
09:27So we use foraminifera, or forams for short. And they are tiny plankton. And during their lifetime, they build a shell. And that shell is preserved in these cores.
09:42Sediment samples from the sea floor can reveal how deep ocean currents respond to climate change.
09:49This sample will be gently shaken for two days and then sieved to separate the clay, silt and plankton from the tiny microfossils that have an ancient story to tell us.
09:59Wow. So they're microfossils from a couple of thousand years ago.
10:03Yes. They look like tiny little popcorn.
10:06Really?
10:07Please.
10:08Oh, yeah. They totally do.
10:11In order to take the forams out of the tray, because they are different species, we have these little slides where we put them in.
10:19And I use a little bit of clean water to wet. So I gently approach it, pick it up, and then place it in here.
10:27But you're just looking for the popcorn-shaped ones?
10:30In the popcorn-shaped ones, there are over 20 different species.
10:35Okay.
10:36So you have to identify them correctly.
10:37Oh, wow.
10:38And how many are you looking for?
10:39Maybe 500 would be enough.
10:41Sometimes it...
10:42So you have to pick 500 out of this?
10:43Yes.
10:44Good luck.
10:45The dating and analysis of marine sediment pores can help reveal how Earth's climate and ocean circulation has varied in the past.
11:02Using these natural climate archives, scientists estimate that the AMOC is between 3 and 14 million years old.
11:08Over that time, the AMOC has experienced natural variations, and understanding the complexity of this ancient system takes close collaboration.
11:16Audrey's data can help climate modelers like MetAaron's EndaOD to test and refine AMOC models.
11:23We want to discern between human-forced variations versus the natural oscillations which can last decades, centuries, and even millennia.
11:35If we can recreate what the paleontologists observe, then we can be confident that what we're predicting the future is reliable.
11:42AMOC responds to changes in climate, ocean temperature, and salinity, which can be caused by a number of factors, such as melting fresh water from the ice sheets.
11:52Enda can simulate these changes in the models, but the computational power required to capture such a vast ocean in detail can be very expensive.
12:01Instead of doing that, we look at the key areas that really matter, that really affect AMOC, and we use a very high resolution grid for those places.
12:09We get much improved AMOC simulations, but at a much lower cost.
12:12And what are some of those key areas that you're looking at?
12:15So some of the key areas include the Gulf Stream separation off the coast of America, the sills between the Arctic and the Atlantic, that's between Greenland, Iceland, and Shetland.
12:26And believe it or not, even the Mediterranean is important because of Mediterranean outflow at mid-depth also affects AMOC as well.
12:33Enda is particularly interested in the Denmark Strait, where deep Arctic water flows over ridges and sills into the Atlantic.
12:41Traditional models show how the temperature changes by depth in this area, but they can miss important details.
12:48Their blocky grids average out temperatures and fail to represent the flow near the seabed.
12:53Regional models, on the other hand, are far more detailed.
12:57They follow the shape of the ocean floor more closely, adding smoother layers and capturing the flow near the seabed as it travels from the Arctic into the Atlantic.
13:06AMOC has kind of hit the news headlines a bit over the last few years about collapsing in the next 50 years or 100 years.
13:31What's the most sober assessment of it?
13:33Some of the studies, they're actually deliberately collapsing the AMOC.
13:37They deliberately enter an unrealistic amount of fresh water just to see what would happen.
13:41Because it's very important to understand if it did collapse, how would we deal with that situation?
13:46Yeah.
13:47However, it's not often reported that they are quite unlikely events in the future, and that's something we need to be clear about.
13:52The more likely is a gradual slowing down of 35% to 45% by 2100.
13:57And that's kind of where we're concentrating in Med-Aaron.
14:00But of course, research is active and we're always watching the latest literature.
14:05Understanding all this is kind of crucial for the future.
14:08Is there anything else we can do to kind of help?
14:11We need to reduce our carbon emissions. Each effort we make on that will make the extreme events less likely.
14:19And we really want to avoid extremes.
14:21Inevitably, there will be some adaptation needed, but the degree to which we have to adapt will depend on how much we mitigate in the first place.
14:28And the work that you are doing and your colleagues are doing is to kind of give us a better picture for the future so we can plan and adapt.
14:34Absolutely, yes.
14:58Let's step back in time, 55,000 years to be precise, to a small limestone cave in France called Grotte Mandra.
15:25In the cave, an ancestor of ours lights a fire.
15:29But little do they know that the carbon from those flames would go on to rewrite human history and leave a mark as the earliest record of Homo sapiens in Western Europe.
15:4110,000 years earlier than previously thought.
15:45When the fire was lit, the smoke left a layer of black carbon or soot on the cave walls.
15:52Then, the following season, a thin layer of calcium carbonate called a speleothem covered it over.
15:59This cycle was repeated again and again, giving rise to thousands of layers of tell-tale thickness that under a microscope can be read, just like how we use tree rings to date the age of trees.
16:12By comparing the timing of fires with fossilised teeth and tools found in the cave, a team of scientists concluded that not only did Homo sapiens and Neanderthals occupy the cave within one year of each other, but that our ancestors arrived in this part of Europe much earlier than previously known.
16:35Every action leaves a trace, and carbon provided the smoking gun of an act by a modern human hand.
16:45After all, there's no such without fire.
16:50See you next time.
16:51We know we have to cut emissions to avoid the worst impacts of climate change.
17:08But can we do more to reduce the amount of carbon dioxide in our atmosphere?
17:13A team of researchers here in Trinity has spent the last ten years tackling just that problem, figuring out how to take carbon out of the air.
17:21Wolfgang Schmidt is a material scientist and synthetic chemist at the Amber Research Centre.
17:27I would say climate change is arguably the greatest societal challenge that we have.
17:34Currently, the levels of CO2 in the atmosphere are 420 to 430 ppm, which are the highest level in human history.
17:45So it's actually a real scientific challenge to pick out these molecules, to remove the molecules.
17:52So it's a fascinating challenge to do this.
17:54And so if you want to take carbon out of the air, where do you even begin to tackle that problem?
18:00The process is described as direct air capture.
18:04So you need a material, you need to design a material that picks up the CO2, that absorbs the CO2 from the air, and also potentially releases it on demand.
18:15Wolfgang and his team have spent years designing and testing a number of materials to draw carbon dioxide out of the air.
18:23A key development was this material that contains a special surface that binds the CO2 molecules and releases them again when heated.
18:31We decided to go with this approach because it allows us to use waste heat.
18:39What does waste heat mean?
18:41Heat that is generally associated with industrial processes and is difficult to harness.
18:47So for instance, in Ireland, it would mean in 2030, I think approximately one third of the electricity used in Ireland is used in data centers.
18:57However, most of this electricity that enters the data centers translates to waste heat.
19:07Wolfgang and his colleague Sebastian show me how the air filter device works.
19:11As air is drawn in, the CO2 molecules stick to the innovative material inside.
19:17By monitoring the levels at the filter exhaust, we can see that the levels have dropped, indicating an impressive 90% of the carbon dioxide has been captured.
19:26But this isn't just a lab experiment.
19:29We're heading to Dublin airport, where the technology is being put to the test in the real world.
19:36So it's going very well.
19:38The instrument performs very reliable across all weather conditions, even today.
19:44So the humidity does not really influence the performance of the instrument.
19:49We capture approximately two to five tons of CO2 per annum.
19:55There's also some room for improvement.
19:57For instance, the insulation or the heat management in the system could be a little bit improved.
20:02This would allow us to run faster cycles and the productivity would be higher and the energy consumption would be lower.
20:11So now you see inside of the instrument, so this is actually the capture vessel where the porous material is inside.
20:18And so how much of your absorbent material is in here?
20:21So in the laboratory we had 500 grams and here we've got now 100 kilograms of adsorbent in there.
20:27Well, 200 times more.
20:28200 times more.
20:29Brilliant.
20:32The airport is an ideal location to test a direct air capture device, and it could offer valuable opportunities for the future.
20:41The aviation industry emits significant quantities of CO2, and the industry needs to adopt sustainable aviation solutions to meet the climate target.
20:52In particular, the aviation industry will in the future more and more use sustainable aviation fuels, for which CO2 could be a feedstock.
21:03We are also not very far from greenhouses here at the Dublin airport, where strawberries are grown.
21:10The test here allows us to demonstrate the technology to the agricultural industry, which could use CO2 to enhance growth in greenhouses, to increase the yields.
21:21So there's a lot of different benefits.
21:22There are a lot of different benefits.
21:24Direct air capture isn't a silver bullet for reducing our CO2 emissions, and the technology has to run efficiently to be truly sustainable.
21:43But these portable systems could be scaled up to help us build a cleaner, lower carbon future.
21:50So Wolfgang, what's the long term goals of this project? Where do you want to see it go?
21:54We are at the moment designing a 400-ton system, a system that captures up to 400 tons of CO2 per annum.
22:03We would like to develop this technology to be used in conjunction with waste heat, with waste heat suppliers, data centers, with incinerators.
22:12Excellent.
22:13From the outside, this system looks deceptively simple, but inside these boxes is cutting edge technology that represents a decade of research.
22:23And this system has such exciting potential, not only as a tool for the circular economy, but also as a way to help clean up our air and secure our planet's future.
22:32That's our 10 things to know about carbon.
22:45Next time, we explore the hidden world of bacteria, and the urgent fight against antimicrobial resistance.
22:51We'll see you next time.
Be the first to comment