METHANE. Detectives: Making the Invisible Visible 的完整文字稿

00:05:37.120 The point of this kind of equipment is to do uh leak detection and repair, meaning you can spot a leak and then fix it depending on like the type of equipment in uh good timing. 00:05:37.279 --> 00:05:40.399 So I cannot calculate the quantity of methane leaving. 00:05:40.639 --> 00:05:47.680 As a thermographer with experience, we get to know if uh the emission is significant or not. 00:05:47.920 --> 00:05:51.920 But this is empirical, it's not based on any sort of calculation. 00:05:52.879 --> 00:06:04.319 If the cameras only give qualitative confirmation of leaks, how can teams like Theo's move from just spotting them to knowing how serious the level of emissions are? 00:06:05.120 --> 00:06:09.279 Well, now you have to bring in a combination of techniques. 00:06:09.600 --> 00:06:33.680 In order to have a comprehensive approach on mass and emissions coming from a site, you will try to combine uh different types of equipment like sniffers, uh, remote sensing, airborne remote sensing, meaning a plane flying over using a spectrometer over the site or the oil field, gas fields, as well as OGI cameras to have an overall uh idea of the number of sources. 00:06:34.000 --> 00:06:44.560 You combine them in a way that someone using a spectrometer, meaning like an instrument that actually gives uh the particle million of methane every few seconds. 00:06:44.800 --> 00:06:48.959 It will give you a sort of estimate, but you won't know what's the source. 00:06:49.199 --> 00:07:02.000 An OGI, an optical gas imaging camera can give you the source but cannot give you an estimate, and it's the combination of all these tools that can give you a comprehensive and broad idea of methane emissions in the site. 00:07:10.879 --> 00:07:13.199 But what do you do if you don't have a camera? 00:07:13.519 --> 00:07:20.399 Okay, so on top of the vehicle, we have this thing that looks like a big claw at the front. 00:07:20.720 --> 00:07:25.680 Dave Lowry is a professor of geoscience at the University of Royal Holloway in London. 00:07:25.920 --> 00:07:30.000 He's been studying atmospheric methane for over 30 years. 00:07:30.480 --> 00:07:31.920 I'm Dave Lowry. 00:07:32.079 --> 00:07:36.959 I'm a reader in stabilised topes and greenhouse gases in the Earth Sciences Department at Royal Holloway. 00:07:37.279 --> 00:07:47.839 Together with another world expert on methane, Ewan Nisbet, he set up the UK's first monitoring station for atmospheric methane right on the roof of their very own building. 00:07:48.800 --> 00:07:54.639 And I set up the lab with Ewan Nisbet, Greenhouse Gas Lab, back in 1995. 00:07:54.959 --> 00:08:01.680 Today, the readings from Royal Holloway provide one of the longest running records of atmospheric methane in Europe. 00:08:02.240 --> 00:08:05.600 Dave works closely with another atmospheric scientist, Dr. 00:08:05.680 --> 00:08:13.839 Rebecca Fisher, and about 10 students to help identify and understand methane sources from sites all over the world. 00:08:14.079 --> 00:08:14.800 Here's Dr. 00:08:14.879 --> 00:08:15.600 Fisher. 00:08:16.000 --> 00:08:20.560 So we get air samples sent into our lab from a number of sites globally. 00:08:20.879 --> 00:08:24.000 I started off looking at Arctic methane. 00:08:24.160 --> 00:08:33.440 So we've got measurements coming, air samples coming from Spitsbergen, for example, part of the Spaubards archipelago, northern Norway. 00:08:34.480 --> 00:08:43.360 We have air canisters filled there several times a week, sent to our lab where we measure the methane concentration and the isotopes in the methane. 00:08:43.840 --> 00:08:47.679 We also have air samples from Ascension Island, 8 degrees south of the equator. 00:08:47.840 --> 00:08:53.120 And then more recently the Halley station in Antarctica is another site where we've been receiving air. 00:08:53.279 --> 00:08:55.200 So it's it really is global. 00:08:55.519 --> 00:09:07.200 While Dave and Rebecca have been measuring and analysing methane from around the world for many years now, what they're really interested in showing me is this vehicle with the thing that looks like a big claw on the top. 00:09:07.759 --> 00:09:13.279 That's an anemometer, a sonic anemometer for measuring wind speeds as we're driving along. 00:09:13.440 --> 00:09:16.639 So that's important when you're trying to calculate an emission. 00:09:16.960 --> 00:09:22.159 The claw, or sonic anemometer, is not the only thing that's special about this vehicle. 00:09:22.399 --> 00:09:28.320 It works with a rare and expensive piece of technology called a mobile laser spectrometer. 00:09:29.039 --> 00:09:31.919 Remember the spectrometer that Theo Human mentioned? 00:09:32.159 --> 00:09:38.159 A device that can give you the actual concentration of methane within a sample every few seconds? 00:09:38.399 --> 00:09:42.240 Well, this is exactly that, except for one key advantage. 00:09:42.480 --> 00:09:43.679 It's mobile. 00:09:43.919 --> 00:09:53.120 That means you can quote unquote see methane leaks as you go through them, turning a normal car into a sophisticated mobile meth lab. 00:09:53.519 --> 00:09:56.159 Meth for methane, not that kind of meth lab. 00:09:56.480 --> 00:10:04.080 Anyway, according to Dave and Rebecca, this laser-based tech was one of the most important jumps forward in our understanding of methane emissions. 00:10:04.559 --> 00:10:21.519 We would have to collect samples of air in flasks and hope that our knowledge of the wind and the source would allow us to predict where the emission was, and then we would bring back the tanks to the lab and make an analysis on the gas chromatograph. 00:10:21.759 --> 00:10:31.840 But as soon as the like the laser-based instruments were commercialized, we didn't need the carrier gases, and suddenly everything was mobile. 00:10:31.919 --> 00:10:45.759 We could even set up at remote sites without carrier gases, so we set up sites in in Ascension Island and in the Falklands and left

instruments running and just logged in remotely to those because we didn't need the consumables. 00:10:48.799 --> 00:10:59.360 It's a technology like this that has started to show us, not just from the top down, but from the bottom up, just how much bigger a problem methane leaks are than we had realized. 00:11:00.159 --> 00:11:05.360 And I was here for a little taste of what it was like to be a methane detective on the move. 00:11:06.000 --> 00:11:13.919 First up, a layman's explanation of how the machine works and some of the smart calculations it has to do to give a reliable reading. 00:11:32.240 --> 00:11:37.120 So you've got to then calculate back to try and understand how much is leaking. 00:11:37.440 --> 00:11:44.320 At the back we have a GPS receiver, so that tells us the concentration of methane at at a fixed point. 00:11:44.559 --> 00:11:48.799 It's measuring methane and uh GPS coordinates ten times every second. 00:11:52.879 --> 00:11:56.960 And with that, it was time to get on the road and start looking for leaks. 00:11:57.120 --> 00:11:58.080 Uh where should I go? 00:11:58.320 --> 00:11:58.960 Front? 00:12:00.000 --> 00:12:00.559 Front or back? 00:12:00.720 --> 00:12:02.240 Do you want to go in the back and want to look at the data? 00:12:02.399 --> 00:12:02.639 Yes. 00:12:03.519 --> 00:12:05.039 Uh which is the best side? 00:12:05.840 --> 00:12:07.120 I I to be I don't know. 00:12:07.360 --> 00:12:17.519 Inside, the car felt like any ordinary, fairly comfortable car, except for the massive battery packs and instruments in the boot, and the wires coming over the seats. 00:12:17.759 --> 00:12:23.600 Looking at the data meant watching lines move across a tablet screen that connected to the spectrometer. 00:12:23.919 --> 00:12:29.919 There's a baseline at roughly 2,000 parts per billion as we're driving along, and then we've just gone through some peaks. 00:12:30.399 --> 00:12:35.039 The biggest one we've been to through so far was over 3,000 parts per billion. 00:12:35.200 --> 00:12:40.480 This is making one measurement every second, so you can see as we go through a leak, we maybe see a few measurements. 00:12:40.639 --> 00:12:45.120 So for a few seconds we could be up above 3,000 parts per billion. 00:12:45.440 --> 00:12:54.159 It was amazing to watch the methane profile around me change in real time just by driving along a suburban road in London. 00:12:54.399 --> 00:13:01.919 And concerning to see how many gas leaks were emitting steady puffs of methane all around us. 00:13:02.159 --> 00:13:07.919 So that is literally as we're going gas leak, gas leak, yeah, gas leak. 00:13:08.159 --> 00:13:11.200 Yeah, these sources would be would be gas leaks. 00:13:12.000 --> 00:13:15.200 I asked Rebecca how high they had seen these peaks go. 00:13:15.840 --> 00:13:24.799 How high would it go if we were next to, let's say, a gas leak on a you know a major pipeline or you know how high have you seen it go? 00:13:25.200 --> 00:13:29.519 Probably um 10,000 um parts per billion. 00:13:29.919 --> 00:13:36.799 Um when we were when we took the instrument into a cow barn, um then it can go even higher. 00:13:38.240 --> 00:13:39.360 A hundred thousand. 00:13:43.039 --> 00:13:44.399 And women's a very big space. 00:13:44.639 --> 00:13:45.679 I know this is not the focus. 00:13:46.240 --> 00:13:52.720 One thing our methane detection expedition brought home to me was just how much the mobility of their equipment meant. 00:13:53.120 --> 00:13:57.039 They can essentially look for and measure methane anywhere. 00:13:57.360 --> 00:13:59.360 Where are you going for tomorrow's survey? 00:13:59.759 --> 00:14:22.480 We're going up to to Cheshire, so it's an area we've been to once before, and um it's an area that's a mixture of sources from uh landfill sites, uh above ground gas infrastructure on the distribution network, um, and it's a site that has lots of um like oil refineries and chemical industry. 00:14:24.159 --> 00:14:27.360 So it's it's um a mixed source region. 00:14:27.759 --> 00:14:36.080 And when you say you've been once before, is it uh a part of a regular monitoring program or you just went once before you're interested to go and see it again? 00:14:36.320 --> 00:14:42.480 Well we're doing this as part of um um a project funded by the UK uh RI. 00:14:42.799 --> 00:14:46.960 It was initially set up to look at the effects of of fracking. 00:14:47.360 --> 00:14:59.919 Um so we surveyed to identify all the existing sources so that if there was an emission from fracking, we could identify that as an extra source because we knew where that site was. 00:15:00.320 --> 00:15:09.279 The challenge of detecting methane with the mobile laser spectrometer isn't necessarily finding the emissions, the challenge becomes working out one source from another. 00:15:09.600 --> 00:15:31.440 That was in the middle of um of dairy farming land, so we had cow barns, manure piles, uh, gas leaks along the main road, uh, and a big old landfill that was closed within the region, so there are lots of different sources contributing, and we use our measurement techniques to distinguish all the different ones in the region. 00:15:32.000 --> 00:15:39.120 Those special techniques are the measurements of methane isotopes, which Dave and Rebecca happen to specialise in. 00:15:39.600 --> 00:15:41.120 That word isotopes. 00:15:41.679 --> 00:15:42.720 Does it sound familiar? 00:15:42.879 --> 00:15:46.000 Here's Professor Philippe Sies again from the last episode. 00:15:46.159 --> 00:15:51.360 He's a climate researcher at the Climate and Environment Science Laboratory in Paris. 00:15:51.840 --> 00:16:01.519 When we see methane increasing uh just with the concentration signal, we're not able to split it into oh, this is agriculture, this is waste, this is uh oil and gas. 00:16:01.840 --> 00:16:08.000 However, we still have some atmospheric toolkits which are called methane isotopes. 00:16:08.639 --> 00:16:17.200 Isotopes mean two

specimens of the same atom, just that one has more neutral particles or neutrons in its nucleus than the other. 00:16:17.600 --> 00:16:24.960 In the case of isotopes of methane, it's the carbon atom in the middle of the methane molecule that bears the telltale difference. 00:16:25.919 --> 00:16:34.480 So um we're looking at methane, and depending on how that methane was formed, um, the methane can be slightly heavier or slightly lighter. 00:16:34.720 --> 00:16:37.120 Most carbon is carbon 12. 00:16:37.840 --> 00:16:39.600 What does the 12 mean? 00:16:39.919 --> 00:16:44.960 It's uh the number of um protons and neutrons within within the carbon atom. 00:16:45.120 --> 00:16:45.279 Okay. 00:16:45.679 --> 00:16:48.000 Six protons, six neutrons. 00:16:48.639 --> 00:16:56.159 Um but you can have uh carbon with one extra um neutron, and that's slightly heavier than the carbon-12. 00:16:56.480 --> 00:17:01.279 Making them carbon-13, six protons, seven neutrons. 00:17:01.600 --> 00:17:04.880 These are also stable atoms, but they're a lot more rare. 00:17:05.359 --> 00:17:19.440 And it just so happens that thermogenic methane, that's the methane given off by oil, gas, and coal, has more carbon-13 than biogenic methane formed by bacteria decomposing organic matter. 00:17:19.680 --> 00:17:20.720 Philippe Siez again. 00:17:32.480 --> 00:17:50.480 So it's not able to separate rice from wetlands or livestock from rice, but uh it can classify the emissions into two categories the uh bacterial uh processes and the uh leaking of oil and gas. 00:17:50.880 --> 00:17:52.480 Back to Rebecca Fisher. 00:17:53.119 --> 00:18:18.960 So using a mass spectrometer, we can measure the ratio of carbon-12 to carbon-13 within um the methane in an air sample, and that very, very small changes um in that ratio tell us whether there is a little bit more of a biogenic source or a little bit more of a thermogenic source, the methane formed at higher temperature. 00:18:19.200 --> 00:18:22.480 What would a totally biogenic source look like in terms of acid? 00:18:22.880 --> 00:18:24.880 Um that has mostly carbon-12. 00:18:25.200 --> 00:18:32.480 They all have mostly carbon 12, but there's more carbon-12 than very little carbon-13 in a logical biogenic source. 00:18:32.720 --> 00:18:32.960 Okay. 00:18:33.279 --> 00:18:47.440 Um if that methane is formed at higher temperature, thermogenic fossil fuel gas or methane um formed during coal formation, um, then there would be um a little bit more carbon-13. 00:18:48.079 --> 00:19:01.680 Um, and if it's a combustion source, so um this could be forest fire or it could be combustion from a vehicle, um, then there would be more carbon-13 again, so it's slightly heavier. 00:19:01.920 --> 00:19:08.000 So you're going from you'd always have more carbon-12 than more carbon than carbon-13. 00:19:08.240 --> 00:19:10.160 99% of the carbon is carbon 12. 00:19:10.240 --> 00:19:10.400 Right. 00:19:10.880 --> 00:19:14.960 Very small um differences in the ratio depending on the source. 00:19:15.119 --> 00:19:19.599 So you the lowest amount of carbon-13 that would suggest a biogenic source. 00:19:19.759 --> 00:19:20.240 Yes. 00:19:20.559 --> 00:19:27.119 Slightly more carbon-13 like would suggest a fossil fuel source, a thermogenic. 00:19:27.440 --> 00:19:27.680 Okay. 00:19:28.160 --> 00:19:34.319 And then slightly more again would suggest a combustion source. 00:19:34.960 --> 00:19:46.880 Today, Dave and Rebecca work in partnership with students and scientists all over the world, stepping up our baseline knowledge of methane emissions profiles in different areas using these isotopic distinctions. 00:19:47.039 --> 00:19:50.240 We speak to one of these scientists in the next segment. 00:19:51.119 --> 00:19:55.279 Back in London, my own methane detective expedition is coming to an end. 00:19:55.519 --> 00:19:57.279 So we're now driving back into campus. 00:20:01.599 --> 00:20:03.119 2,000 parts per billion. 00:20:03.279 --> 00:20:07.279 That's not that far off the global average of about 1,900. 00:20:07.440 --> 00:20:11.839 But some of the peaks on the profile of our journey went way beyond that. 00:20:12.400 --> 00:20:15.759 And if we look at the total journey. 00:20:15.920 --> 00:20:16.640 Oh, we had a few. 00:20:16.880 --> 00:20:17.599 Quite a lot of peaks. 00:20:17.920 --> 00:20:18.160 We did. 00:20:18.319 --> 00:20:21.279 There was one that was above 4,000 parts per billion. 00:20:21.599 --> 00:20:27.359 When you uh zoom out like that, it looks like a sort of, I don't know, the skyline of Dubai or something. 00:20:28.000 --> 00:20:31.680 The difference when a simple pipe had been replaced was stark. 00:20:31.839 --> 00:20:37.039 I could see right there on the screen the very different profile that such a simple measure could achieve. 00:20:38.400 --> 00:20:41.680 Yeah, and we had periods where there weren't many leaks at all, yeah. 00:20:41.920 --> 00:20:47.279 Um potentially because they have been here and maybe they've fixed this section, but they haven't fixed that section. 00:20:47.839 --> 00:20:50.400 There was a you know, pipeline has been replaced in that area. 00:20:50.640 --> 00:20:51.279 Probably is. 00:20:51.440 --> 00:20:55.759 You do see improvements when um pipelines have been replaced. 00:20:56.480 --> 00:20:59.759 Oh right, so they might have just had a whole like switch that's newer. 00:21:00.079 --> 00:21:00.319 Yep. 00:21:00.559 --> 00:21:17.680 With these two areas with the peaks, if they were to replace the pipelines in those, then I mean if you if you target that well enough, you could change the overall methane profile of a large region if you just carbon dioxide. 00:21:17.839 --> 00:21:19.920 Ah yes, that was lots of traffic. 00:21:20.160 --> 00:21:23.200 And the water's done some odd things. 00:21:23.599 --> 00:21:24.880 Oh no, no, it hasn't. 00:21:25.200 --> 00:21:28.240 It's just been what? 00:21:28.480 --> 00:21:29.759 We drank through rain. 00:21:29.920 -->

00:21:34.880 No, it's all just been roughly 13,000 parts per million for the water. 00:21:36.000 --> 00:21:45.680 A baseline of around 400 parts per million of carbon dioxide, and a baseline of 2,000 parts per billion for methane. 00:21:45.839 --> 00:21:46.480 Yep. 00:21:47.279 --> 00:21:49.200 Amazing, thank you. 00:21:50.079 --> 00:21:57.599 And finally, Thomas Rookman is a professor of atmospheric physics and chemistry at Utrecht University in the Netherlands. 00:21:57.839 --> 00:21:59.519 When the realization started to dawn. 00:22:00.319 --> 00:22:06.400 Internationally, that methane emissions from oil and gas could be a much bigger climate problem than we realized. 00:22:06.640 --> 00:22:17.839 Professor Rookman was charged with coordinating a huge international contingency to conduct a study of the emissions from one country's oil and gas sector in particular, Romania. 00:22:26.640 --> 00:22:28.559 The idea was simple. 00:22:28.960 --> 00:22:38.160 Romania has a centuries-long history of oil and gas production and has for many years reported its methane emissions to the United Nations. 00:22:39.119 --> 00:22:48.000 But, like most oil and gas reported emissions, these were estimated or calculated based on potentially outdated emissions factors. 00:22:48.160 --> 00:22:55.519 Actually, measuring them offered the chance to compare estimates of a country's methane emissions with actual measurements. 00:23:28.960 --> 00:23:32.000 Could you summarize the project in a few words, please? 00:23:32.640 --> 00:23:34.079 Yes, uh, thank you. 00:23:34.319 --> 00:23:50.160 Um the Romanian project on methane emissions from oil and gas was carried out by a large group of scientists from more than 10 European countries, also US scientists, and it was commissioned by the United Nations Environment Program. 00:23:50.559 --> 00:23:57.119 They asked our scientific group to come to Romania and carry out measurements in the oil and gas infrastructure. 00:23:57.440 --> 00:24:02.559 Prior to the Second World War, Romania was the largest oil and gas producer in Europe. 00:24:03.039 --> 00:24:15.839 Today its output has dwindled, but its processing capacity is still significant for its Eastern European context, with over nine refineries and an extensive array of onshore and offshore infrastructure in the Black Sea. 00:24:16.000 --> 00:24:29.119 It also has ambitions to reinvigorate its energy producing credentials, with huge investments in its offshore capacity and funding from the EU for major pipeline extensions to its existing network. 00:24:29.599 --> 00:24:34.720 But much of that existing infrastructure is old and has been poorly maintained. 00:24:34.960 --> 00:24:41.920 Environmental groups and regulators are concerned about the impacts, not least, of fugitive methane emissions. 00:24:42.319 --> 00:24:50.319 Old infrastructure means leaky infrastructure, and vast networks of pipes mean vast networks of leaks too. 00:24:50.559 --> 00:24:55.680 From a scientific point of view, then Romania's situation offered a great opportunity. 00:25:01.759 --> 00:25:08.319 And so since Romania is so important, it also reports high emission rates to the United Nations. 00:25:08.559 --> 00:25:12.319 The question is, is that true and what are these reports based on? 00:25:12.480 --> 00:25:24.000 So they asked us to use our new techniques that we have developed to come to Romania, and there we visited many locations, and we first tried to find out how many of them actually emit methane. 00:25:24.160 --> 00:25:36.960 So you can see that from the outside, or can measure from the outside what are the components that are emitting the methane, how much methane is emitted, and that's what we have finished now and compared it to what actually the countries report. 00:25:37.119 --> 00:25:39.839 But we have now quite a good idea on all these aspects. 00:25:40.000 --> 00:25:46.799 So what is leaking, where is it leaking, how much is leaking, and how does it compare to the national estimates? 00:25:47.119 --> 00:26:02.480 Some of the technology used included drones and aircraft that could survey sites from the air, chemical detectors called sniffers to assess minute changes in methane concentration, thermal cameras that can make the gas plumes of methane suddenly visible. 00:26:02.720 --> 00:26:09.200 Even satellites can now detect large methane plumes from leaks, vents, or flares from space. 00:26:09.839 --> 00:26:22.319 Combining all these findings and then running them through still more sophisticated instruments for analysis created one of the most comprehensive measurement studies to date of methane emissions from an oil and gas industry. 00:26:22.960 --> 00:26:24.160 And what did they find? 00:26:24.880 --> 00:26:26.559 You've probably guessed already. 00:26:27.440 --> 00:26:28.640 And is it scary? 00:26:28.799 --> 00:26:32.960 I mean the the emissions are higher than you have expected, right? 00:26:33.599 --> 00:26:41.359 Yes, the emissions are higher than what is reported to the International Energy Agency and also the United Nations. 00:26:41.759 --> 00:26:42.640 How high? 00:26:42.880 --> 00:26:49.440 Looking just at oil, the study found methane emissions of 5.5 kilograms per hour per site. 00:26:49.599 --> 00:26:52.799 That's about 120,000 tons per year. 00:26:53.039 --> 00:26:55.680 Compare this to the reported emissions. 00:26:55.920 --> 00:27:01.359 46,000 tons is what Romania reported to the United Nations for the same period. 00:27:01.680 --> 00:27:05.359 23,000 is what the IEA had calculated. 00:27:05.680 --> 00:27:12.400 What's more, the study found that almost three-quarters of the detected emissions were from gas being vented. 00:27:12.720 --> 00:27:19.440 When it came to leaks, there were over 230 leaks identified that hadn't been accounted for. 00:27:20.640 --> 00:27:22.720 But here's the positive angle. 00:27:23.440 --> 00:27:29.920 That means that what the EU thought in the past years on what they had already

achieved in Romania is not achieved yet. 00:27:30.079 --> 00:27:48.559 It also means that now we have the chance, since we know now from the measurements, how high the emissions are, now we have the chance to actually reduce these emissions and help the EU or well, Romania and the EU to fulfill some of the obligations that we have to do in the Paris Agreement and this global methane pledge, for example. 00:28:17.599 --> 00:28:25.519 It highlighted the fact that to fix the problem, you do need to know what and where the problem exists first. 00:28:25.680 --> 00:28:31.599 And this is something Professor Rookman has found time and time again in his other methane studies as well. 00:28:32.079 --> 00:28:35.359 You cannot easily extrapolate from one region to another. 00:28:35.599 --> 00:28:39.440 You have to go to the regions and actually measure what you find. 00:28:39.599 --> 00:28:45.519 We have measured in total in Europe in 11 cities, and we find that all cities are different, for example. 00:28:45.599 --> 00:28:50.960 So there's no, we have been in Bucharest as part of our project here in Romania. 00:28:51.119 --> 00:28:53.920 We have measured methane emissions in Bucharest. 00:28:54.079 --> 00:28:59.759 We found quite a number of gas leakages, but we also find quite some methane emissions from the wastewater system. 00:28:59.920 --> 00:29:02.319 That was quite special from Bucharest. 00:29:02.480 --> 00:29:10.799 In comparison, for example, to Utrecht, where I live, where we find very little wastewater emissions, but the most of the emissions are dominated by the fossil fuels. 00:29:10.880 --> 00:29:17.759 So in Bucharest, the emissions are overall larger, but also a larger fraction is coming from biological or microbial sources. 00:29:18.079 --> 00:29:29.119 We have also measured in in Paris, and in Paris we found out that actually gas boilers and restaurants have higher emission rates, which is different from Romania. 00:29:29.359 --> 00:29:30.880 We haven't found that very much here. 00:29:31.119 --> 00:29:35.599 So each city also needs to know what is the best way to reduce the emissions. 00:29:35.759 --> 00:29:42.480 You can set all kinds of targets, but you need to know at which places you can actually achieve this target. 00:29:42.640 --> 00:29:48.240 So you need to know again where the emissions are and how large they are, and at which place which emissions are most important. 00:29:48.559 --> 00:29:52.240 And also then the feasibility options, so what is technologically possible. 00:29:52.480 --> 00:30:01.839 So our role as scientists is to help guide this process, this political process in the end, because we want to find out. 00:30:02.000 --> 00:30:11.119 Well, we want we want to provide data, solid scientific data that can be used as the basis of this policy, of these political goals. 00:30:15.920 --> 00:30:29.759 So, fellow methane hunters, that rounds off the first half of our podcast, where we've covered the main human sources of methane and the threat from its invisible leaks, many of which are lurking all around us. 00:30:30.640 --> 00:30:44.079 But before we open a new chapter on tackling these emissions, one more investigation into the origins of methane emissions awaits, for which we need to turn to the biggest source, the Earth itself. 00:30:44.559 --> 00:30:50.319 When we look at the cycles of greenhouse gases on our planet, we face a sobering reality. 00:30:50.559 --> 00:30:55.440 Natural processes release staggering amounts of methane into the atmosphere. 00:30:55.759 --> 00:30:57.759 Why should we be concerned? 00:30:58.160 --> 00:31:08.240 The answer lies in the ominous concept of methane climate feedbacks, a cycle of events that can accelerate climate change to unprecedented levels. 00:31:08.480 --> 00:31:20.079 From permafrost to wetlands, we'll uncover the hidden mechanisms driving methane emissions in nature and confront the looming specter of methane climate feedbacks head on.