Der anthropogene Klimawandel: Grundlagen, Gefahren und Gegenmaßnahmen | Georg Feulner

DLR Astroseminar Vortrag von Dr. Georg Feulner, Potsdam-Institut für Klimafolgenforschung:: Der Klimawandel ist sicherlich eine der zentralen gesellschaftlichen Herausforderungen des 21. Jahrhunderts. Durch die Verbrennung fossiler Energieträger wie Kohle, Öl und Gas und den damit verbundenen Ausstoß von Treibhausgasen wie Kohlendioxid hat der Mensch die globale Mitteltemperatur bereits um etwa 1 Grad erhöht. Was wird uns erwarten und wie gehen wir damit um?

Mit freundlicher Genehmigung:
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
DLR-ASTROSEMINAR 2023

Welcome to VideoWissen The DLR Astro Seminar in Cologne is about the climate of the earth. Dr. Georg Vollner from the Potsdam Institute for Climate Research has highlighted the anthropogenic climate change, its basics, dangers and countermeasures. If you liked it, don’t forget to leave a like, if you haven’t subscribed to the channel yet,

Definitely do it and now have fun. Bye! Bye. My vita actually has relatively close connections to astrophysics. I originally come from astrophysics, so the astro seminar here at the DLR is of course also a nice forum for me to tell you something about climate change. Unfortunately nothing about astrophysics,

That would be a little less worrying, normally at least. That means we unfortunately have to talk about climate change today, basic dangers and countermeasures. Let’s start very slowly. What are we actually talking about? Climate and climate systems, these are the sizes that actually concern us during the lecture.

And the climate is often defined as medium weather, for example meteorological variables such as temperature, precipitation, wind, measured over a correspondingly long period of time or over a large region. For example, we typically measure over 30 years.

And we can investigate this climate condition and it changes when something changes on the edge of the Earth’s system. The important thing is, of course, that we always talk about medium weather, but that does not only concern the atmosphere. And the climate condition does not only result from the atmosphere,

But in fact it is actually a very complex interplay of the different parts of the Earth’s system. The oceans, of course, play an important role, covering 70 percent of the Earth’s surface. Ice bodies, glaciers, ice shields play an important role. The biosphere, land, vegetation, for example, but also in the ocean,

Plays an important role. And in fact, all of this comes from a very complex interplay. That means, even if we always talk about medium weather, we have to take all these things into account when we talk about climate, climate change and modern climate change. Bye The two most important components, one might say,

Are actually atmosphere and ocean. Just a brief insight into how complex all of this is. These are essentially two momentary recordings of the circulation conditions of atmosphere and ocean at some point in the last year. You can see that a lot is happening there. If we look at the globe on the left,

In the lower widths, in the tropics and subtropics, you can see the wind from the east blowing. In the higher widths, we have the west wind zones. For example, we are in Central Europe or here in the Southern Ocean, above the Atlantic and in the influence area of these west wind zones.

And of course, you can see what you can also see from the weather forecast, for example, in the daytime show. You can see that a lot of complex dynamics are taking place. We have weather systems, low-pressure systems, high-pressure systems, which are still packed on top of these large-scale wind patterns, so to speak.

And of course, this is a very, very complex weather event that we have on the planet. This closely relates to what you see on the right side, on the globe on the right side. There are also flow patterns in the ocean. The surface-near ones are primarily driven by the large wind systems.

You can see the equatorial current, for example, or here the Gulf Stream system, which is actually stretching across the northern Atlantic in countless swirls. That the whole thing is complex, you know, that you can’t predict the weather event very well. You know that, too, in part. The weather reports have, of course,

Become better and better. But you also know that it doesn’t work for a few days. And that’s simply because this event is chaotic from a certain point. That means small changes in the initial conditions, in the measurement data, for example, that we feed into our models,

Can lead to very different weather forecasts after a few days. Meteorologists are trying to control this by running many different models with slightly different conditions, then simply assess the uncertainties and of course also improve the weather models continuously. But in the end, we will come to a limit at some point.

The climate is behaving a little better, because as soon as we measure, we measure a lot of these small-scale disturbances and swirls. And this short-term variability is in a certain way eliminated. And the climate, the climate condition, is to a certain extent, in contrast to the weather, a starting value problem.

If we change the starting values slightly, something completely different can come out. The climate is a marginal value problem. That means the external factors of influence, the sun’s radiation, the greenhouse gas concentrations, I will show you in a moment, are ultimately what determines the climate condition.

This is of course also influenced to a certain extent by this whole internal dynamic. But the climate condition as a whole is predetermined by the surrounding conditions. And that makes life a little easier for us as climate researchers, than the weather forecast might have suggested. This is an astro-seminar.

What are the essential energy sources in the climate system? Well, there is one very, very large energy source in the climate system, and that is the sun’s radiation. It essentially provides almost all the energy for the climate and weather events. That is the all-pervading size. Everything else, heat from the Earth’s interior,

The Earth still loses heat due to the radioactive decay of elements in its interior, for example, industrial heating or geological friction, as the sun kneads through the Earth’s crust in the lunar system and causes friction losses. You can essentially neglect all of this if you are interested in the large energy balance. Locally,

This can definitely play a role. For example, it influences industrial heating in the regions where a lot of it is produced, of course, the local weather and climate events. But globally, this is not a particularly dominant effect. What happens to the sun’s radiation that falls on the Earth?

This is the energy balance of the Earth’s atmosphere, as best known and determined from measurement data. The uncertainties are indicated here below the main number in brackets, and the units are watts per square meter. If we start up here, we first look at what happens above the Earth’s atmosphere, i.e.

At the top of this diagram. On the left, you can see that the Earth receives 340 watts per square meter of sun radiation per year. This is essentially the solar constant divided by a factor of four due to geometry. We know this from satellite measurements of the sun’s brightness.

You can also see that about 30 percent of it is reflected back into space, predominantly from the bright clouds, but partly also from the Earth’s surface. Think of desert areas, think of even the oceans, not all of them are exposed to sunlight. Think of ice- or snow-capped regions.

This means that the surface and the clouds also reflect radiation back into space, so that a net of only 240 watts per square meter is absorbed by the system. They are absorbed, they are absorbed by the system, predominantly from the Earth’s surface. You know this from a sunny day. When the sun shines,

The ground and the ground-nearby layers of air warm up, simply because this sun radiation is absorbed by the Earth’s surface. A part of it is actually also absorbed directly, as you can see on the far left in the diagram of the atmosphere, but this non-reflected sun radiation,

Which is not reflected by the clouds and not reflected by the ground, warms up the ground. As I said, you know this from a clear summer day. This warm ground, if it does not want to keep heating up, it has to somehow release this energy again. And it does this in different ways.

There are a few transport processes from energy into the atmosphere, for example through evaporation. When water evaporates on the Earth’s surface, energy has to be brought up, and when this moisture condenses again in the atmosphere, this latent heat is released again. This means that there is this transport term. By rising air layers,

Heat transport also takes place in the atmosphere, but the heated ground radiates this back, namely heat radiation in the infrared. And this heat radiation actually mostly escapes back into space. You can see this up here, at the top right in the diagram. 239 watts per square meter go back into space.

But there is something in between, and that is greenhouse gases. These are simply gases such as hydrogen, carbon dioxide, methane and other gases that actually absorb part of this energy in the infrared area, in the area where the warm earth’s surface radiates. This is of course radiated in all directions,

But there is also a back radiation term that actually warms up the ground more, which would be the case if there were no greenhouse gases on the planet. This is also good, because without this greenhouse effect, the average temperature on earth would be -15 degrees Celsius.

That would be a bit uncomfortable for life on earth. So it’s good that there is a greenhouse effect. What we are doing at the moment is screwing it in and additionally strengthening this greenhouse effect. Second note, since you are all astro-seminar professionals, you can calculate and you see that something is missing, Mr.

Voellner, that doesn’t go up there. Climate scientists cannot calculate. But you can see down here that there is a net thermal absorption of the earth’s system, simply because we are changing it continuously. Because the earth is warming up,

The earth’s system actually absorbs an additional amount of energy at just under a watt per square meter. That means we are not in a state of equilibrium, where radiation and radiation actually become exactly the same. The earth is not in equilibrium in terms of radiation balance, but actually absorbs a part of it.

If you want to change that now, if you really want to change the climate, then you could screw all these screws somewhere. If you had the power, you could make the sun brighter or darker. Of course you can’t. You can do something to the clouds, do something to the ground.

We do that in part by changing the land surface. But the main screw we screw on is actually this one. We change the greenhouse gas concentration in the atmosphere by adding additional greenhouse gases, such as carbon dioxide, methane and others.

This leads to an increase in this back-lit part and thus to an additional warming beyond the natural greenhouse effect. And how do we do that? You all know that we do this because we are still burning fossil fuels. Like here in East Germany,

We have large coal-fired coal-fired areas with the corresponding combustion in the large power plants. And we still do that, even strengthened again since last year. And of course we don’t just do it like in Germany, we still do it worldwide and you will see the effects of it in a moment. Actually,

The climate change and the already noticeable effects of climate change should be enough of a warning sign. But sometimes we need crises that shed a little light on mistakes. If you think back to the last year or the last few years, we all had a hobby, or many of us at least.

For a long time, our hobby was to look at such curves on a regular basis. What is the corona pandemic doing? What about incidents, hospitalizations, intensive care beds, etc.? And this pandemic has shed a light on, if I may be so clear, on the shortcomings in the field of digitization, education and health.

So, very clearly, we have seen in this pandemic that we are very, very badly positioned in some areas. Unfortunately, not much has changed about it. And the new hobby that we got last year is that we then looked at curves a little more closely, like these.

What is the filling rate of our gas storage? Can we heat our houses in winter at all? What about our energy consumption and the costs involved? And as I said, it would actually have been sufficient to take climate change as an opportunity to change something. We have known for 30,

40 years that we are running into this problem. But apparently it has to get even closer to us and the question of whether we can still heat in winter, to realize that this dependence on fossil fuels is not only bad for the planet, but also for us. Actually, not good.

And what is the basic problem? The fossil fuels, coal, oil and gas, contain carbon. This is carbon that was eventually removed from the atmosphere over photosynthesis, millions of years ago, and stored as biomass. It was stored for a very, very long time. And we burn this carbon very, very quickly.

And in this combustion, oxygen is released. That’s what we ultimately want. But it also releases carbon dioxide. And carbon dioxide is an important greenhouse gas in the atmosphere. We don’t just know that we do it. We also know how much we release. If we look at the figures from 2021,

That’s the last year the analysis has been completely completed. This year, mankind has released 9.9 gigatons of carbon from the combustion of target energy sources and from cement production. That’s 9.9 billion tons of carbon that were introduced into the atmosphere. That’s a lot. You can now convert that,

If you have the mass of the atmosphere, you can convert it to how the CO2 concentration, the amount of CO2 in the air, would have to have changed. You would expect an increase of 4.6 ppm, so parts per million, so parts per billion of air, normally with regard to volume,

The concentration would have to increase this year. The measured increase is actually lower. It’s only 2.5 ppm, so parts per million, And that’s because nature is helping us at the moment. Not everything we emit into the atmosphere stays there. Part of it is absorbed by land vegetation, which leads to additional growth,

Partly also by the oceans, where it has a negative effect, namely to the oxidation of the ocean, which we can also measure directly. At the moment, The land vegetation and the oceans absorb about a quarter of our CO2 emissions at the moment. But that doesn’t have to stay that way.

The CO2 level changes when the oceans heat up, And the land vegetation must also be able to grow. If you look at the world in Germany, the growth conditions were very poor due to the effects of climate change. We can measure the CO2 concentration in the atmosphere directly.

We can also measure the annual change, the increase, These are the increase rates that were measured at various places in the world for the global CO2 concentration. You can see that here from 1960 to 2022. These are the latest data. You can see different things.

You can see that it fluctuates from year to year. This is partly due to changes in our emissions, where, as you can see, they have a more increasing trend over time. This is mainly due to natural climate variability, natural climate fluctuations.

And they influence the amount of emissions that are absorbed by the oceans or land vegetation. If the growth conditions are a little worse for the plants, a little less is absorbed. And the increase in our emissions is stronger and vice versa. Or if the ocean conditions change from year to year,

This leads to these fluctuations. But you can also see that we are not on a path where the emissions would decrease in any way or the increase in CO2 in the atmosphere decreases. And you can see that even more clearly in this so-called Keeling curve,

Which was started by Charles Keeling in 1958 or so. Direct measurements of the CO2 concentration in the earth’s atmosphere on the Mauna Loa volcano in Hawaii. When Charles Keeling started these measurements, the CO2 concentrations were, you can see it here on the far left, These are, in turn, the last data.

If you look at the far right, you can see that we have now reached 420 ppm. That means that in the period of these measurements the CO2 concentration has increased by about 30% since the late 1950s. And if you look at the 19th century, the period of massive industrialization,

Then the increase is 50%. We were at 280 ppm. And what you have just seen in the increase rates, you can see here too. This is a curve that is curving upwards. That means that this increase is still accelerating. I said it to Mr. Geider earlier,

It is probably one of the most frustrating curves that we have to reduce emissions. And you don’t see any effective climate protection in this curve. Nothing has happened in the last three decades. And we miss that. I’ll come back to that later. Now to the feet.

It is often asked about the effects of the pandemic by less transport, air traffic, etc. Yes, you can actually see this dent due to the COVID pandemic. But we were back on the emissions level relatively quickly before the pandemic. And in fact, And it leaves behind,

You can see a very small slowdown of this increase, but you don’t see a really strong signal of this pandemic. Now CO2 is not the only greenhouse gas. Another greenhouse gas that even has a much stronger effect than CO2. But a little more briefly. In the atmosphere is methane.

We can also measure the methane concentrations directly. You can also see the last measurement data here. Actually only since the 1980s. You can see that we had an increase there too. Also due to human emissions. Then we had a plateau phase here, around the 2000s.

And what we see recently is actually a very strong increase in the methane concentrations in the atmosphere. That’s not good. I already said, methane is a greenhouse gas that has about 25 times the effect of CO2. The concentration is much, much lower, but it actually has a significant greenhouse effect.

It contributes to warming. And the second thing that is very bad about it, we honestly don’t really know where it comes from. We don’t know how to monitor methane sources. We know roughly what individual states burn in coal, We can somehow understand that. But these methane emissions can be controlled much more strongly.

Of course, this can be losses in the production of fossil fuels, i.e. in gas production or from gas pipelines. We were able to observe certain examples last year. But there are also signs that some natural systems, in the tropics, are actually beginning to release more methane during warming. Both are not nice.

As I said, methane is a very strong greenhouse gas. We have to get a grip on it somehow, but we still don’t quite understand where it comes from. But the big concern is, if natural systems like permafrost soils and water bodies start to release additional methane due to warming,

And of course that’s something we don’t want. Which makes life harder for us, the more we have to reduce our CO2 emissions to actually maintain a certain temperature level. Well, CO2 is released. We can measure this directly, What happens? This is physics and this is not new physics.

This is physics of the 19th century. We know that there is the greenhouse effect. Joseph Fourier was the first to set up something like an energy balance of the Earth’s atmosphere or the planet and found that something was wrong. The Earth is warmer than it should be. And he said,

He had no idea what it was, which is similar to a greenhouse heat radiation. That was his approach. He didn’t know what it was. He just saw that the Earth is warmer than it should be. John Tyndall then simply examined in laboratory measurements how gases absorb infrared radiation,

Whether there is an absorption effect. And he found that gases such as hydrogen, carbon dioxide are actually gases that partly absorb energy in the infrared range. So that was the basis for the concept of the greenhouse effect. And that’s what we’re going to talk about today. This way, the guilty parties were identified,

If they want to, already in the second half of the 19th century. And even the idea that industrialization and the combustion of coal and the release of carbon dioxide could change the climate condition is not a new concept. Svante Arrhenius had already calculated this and just wanted to know,

Is it possible that industrialization warms the climate? He did an experiment and calculated how strong the warming would be if the CO2 concentrations in the atmosphere doubled. He couldn’t imagine that this was even possible. Because industrialization was still in its infancy. There were no longer as many high emissions as we have now.

But he calculated that and came to a value of 5 to 6 degrees. So 5 to 6 degrees global temperature increase with CO2 doubling. This is the so-called climate sensitivity. He was 2 degrees off. Today it’s around 3 degrees.

But this concept that our emissions could lead to a change in the climate condition is not new. We’ve known that for over 100 years. Svante Arrhenius was a bit disappointed. As Scandinavian, But it came a little differently than he might have imagined. So we pumped CO2 into the atmosphere.

There is the three-phase effect. We would expect the Earth to warm up. We can measure this directly at our weather stations. If you had covered the Earth with weather stations without gaps, you could calculate an average surface temperature. Or a ground-near-air temperature. We don’t have this, because we don’t have a gap-free cover.

But we can interpolate the regions where we don’t have any measuring data. There are certain uncertainties. The more you go back to the left in this curve, the greater the uncertainty. We have fewer weather stations. The measurement inaccuracies may be greater.

It’s always good in science if not just one person or one group does something like this. That’s why it’s done by many institutions. You can see them listed here. The Hadley Center in Great Britain. NASA does this. The European Weather Agency does this. You can see the different data sets in comparison.

This curve goes from the 1850s to 2022. We always use this as an anomaly. We don’t measure the absolute temperature, but the change over a certain reference interval. In this case, it’s the reference interval from 1981 to 2010, Why do we do this? For various reasons. It’s easier for quality control. For example,

Weather stations could have a mistake in the absolute calibration of the thermometer. But if they make differences, If you have stations in the neighborhood, the anomalies will correlate with each other over a certain distance. That means they will measure very similar changes, even if the absolute temperature in Kiel and Bremen is different.

The changes will show a similar pattern. This helps them with quality control and with the comparability of different stations. But you can see that all these measurements or calculation methods for global average temperature, as I said, there is interpolation, because we don’t have a gap-free cover, all lead to very similar results.

The Earth actually already warmed up towards the end of the 19th century. And the warming we have now is maybe 1.1°C or 1.2°C compared to the pre-industrial level. You can see many other things in this curve. You can see fluctuations. You saw that the CO2 curve is relatively smooth.

The rise is relatively smooth. The temperature curve is not so smooth. The variability is not so good. The solar activity fluctuates in the 11-year cycle. It has a small influence, on the global average temperature. Occasionally there is a volcanic eruption.

In 1992 the Pinatubo will certainly have contributed to this gap in the temperature. There is El Niño-La Niña, which influences the global average temperature. But unfortunately this trend is still showing up. We see this rise in the global average temperature. A little side story.

The main curve shown here is black with the span of Berkeley Earth. This was started by physicists with a rather climate-skeptical background who said that the way other groups and institutions calculate this is not good. We don’t believe that. But the scientists have calculated this and improved the methods.

They were positive and had to admit at some point that their curve is relatively close to the other curves. But that’s how science works. Results have to be reproducible. If someone with a sceptical background reproduces this with improved methods, then it is only in the interest of science.

But this has actually been confirmed. We can look at this curve in many ways. We can look at the hottest years. This is a popular sport. It’s not always that one hottest year follows the next. We just have these natural climate fluctuations.

But it is noticeable that the warmest years are all somewhere on the right. In the 21st century, for example. That will not change. Then there are many different ways to visualize this rise. One of them is the climate spiral. It’s been going on several times, It became very popular a few years ago.

You can see the months of the year on the outside. We always show month values. You can see the years go by. You can see a temperature scale that increases outwards. You have a 0 degree anomaly compared to the pre-industrial level in the middle. Then it goes outwards.

The target marks of the Paris climate agreement are represented in red circles. This is now running through again. You can see that there are fluctuations. You’ve already seen that in the curve. But overall, this spiral is running outwards. As I said, you’ve already seen that in the curve.

And it is approaching relatively restlessly. Close to the 1.5 degree target mark, Another visualization, Not least through the Fridays for Future movement. These are the warming stripes. Each of these vertical stripes stands for a certain year. In this case, it is the global average temperature. As before, from 1850 to 2021.

They are simply colored. Cooler years are blue, Here, too, you can see certain fluctuations from year to year. As I said, of course, there are also fluctuations in the temperature. Natural climate variability is something we would expect.

But you can also see that the blue years are more on the left and the red years are more on the right. If you want it that way. You can do the same for Germany. Because of the measuring network, 1881 to 2021. And you see a much, much stronger variability.

This is because Germany is of course much, much smaller. Natural climate fluctuations from year to year play a much larger role than if you measure over the entire globe. But in the end, This is the global average temperature. Now, of course, we are primarily interested in how it looks regionally.

What is the distribution over the globe? This is now for 2022. Again anomalies on the left and on the right. And again, the global average temperature. Again, the global average temperature. Again anomalies on the left and on the right. Again anomalies on the left and on the right.

Again anomalies on the left and on the right. Again anomalies on the left and on the right. Again anomalies on the left and on the right. Again anomalies on the left and on the right. Again anomalies on the left and on the right. Again anomalies on the left and on the right.

You can see that the equatorial Pacific on the left in the world map is relatively cool. This is simply because it was a land line year with rather cool temperatures in this area. But you see a pattern that is very robust. Continental regions, land areas, heat up more than the ocean.

This is simply due to the thermal sluggishness of the ocean. You know that when you are on the coast. The climate on the coast gets warmer. In the fall, the heat still remains. This is the same under warming. You can also see that the Arctic is warming up very strongly.

Different effects play a role. Among other things, When it gets warmer, Darker land or ocean areas are coming to light. They absorb the sun’s radiation much better than the light ice and snow areas. This leads to a self-enhancing effect.

The Antarctic is always a bit decoupled by the Antarctic Circumpolar Current and the west winds that blow here. But we also see a similar effect around the Antarctic. In general, continental regions are warming up more. But we live on them now and the polar regions are warming up more.

The Arctic and the Antarctic are warming up more. But this is also a special case. If we move away from these measuring data, if we say that these are temperature measurements, we also see other changes in nature that indicate warming. Then this is of course a clear case.

We see in many mountain regions around the globe and of course in the Alps a melting of glaciers that is also accelerating. You certainly know, this is even relatively old footage, very frustrating comparison images of alpine glaciers in the past and today.

You can also compare it and see what it looks like worldwide. Alpine glaciers actually lose in expansion, in mass, in volume. It is actually accelerating in the 21st century. Individual glaciers are actually growing.

This is because the question of whether a glacier grows or decreases is a balance from the winter snowfall and the summer melting. For individual glaciers it is simply the case that the winter snowfall has to be stronger than the summer melting.

But it is mainly the case that mountain glaciers around the world actually melt. We also see this in Arctic sea ice. I have already pointed out that the Arctic warms up particularly strongly, significantly stronger than the global average. A major diagnostic is simply the expansion of the Arctic sea ice.

This has a very strong annual course. What we typically look at is the minimal sea ice cover in September. This has also been recorded by satellites for decades. These are just two comparison images at the beginning of these satellite measurements.

The minimal expansion of the Arctic sea ice in September 1984 and compared to the year with the lowest expansion so far in 2012. If you look at it as a curve, you can see that this expansion actually has a declining trend.

Even if we have not broken the record from 2012 to today due to local weather changes in the Arctic. But in the end, This is also a beautiful illustration of the ice-albedo recoupling that I mentioned. If you look at this bright area,

It reflects significantly more sunbeam back into space than the dark ocean areas that appear there. This means that it actually reinforces the warming in the Arctic. This has of course an impact on the ecosystems there, on permafrost soils, on the coastal regions for the polar bears, if you will.

This is of course something that has a very strong impact on the region. But of course it also has global impacts on the ice-albedo recoupling and the energy balance of the planet as a whole. The sea level rise is also something that we can measure.

This is now the full range of measurements for the global medium sea level rise since 1880, i.e. for the last 140 years. You can see that it has risen by about 25 cm. It doesn’t sound that dramatic, but it’s not that dramatic yet,

Except for delta regions like Bangladesh or small islands that are very low. They already feel the effects of this today. Globally, this is not much. We know this simply by measuring the levels on the coast. Of course, there are many local effects, but if you simply measure them across the entire globe,

You can see this sea level rise. You can see it in the red data on the right in the diagram. You can see that there is a good harmony and that this sea level rise is actually accelerating. This is not due to the melting of the sea ice. It floats on the water.

That means that when the sea ice melts, it replaces the water that it has previously repressed. So it has nothing to do with the sea level rise. At the moment, this is primarily due to the warming of the oceans. This is a relaxation of the oceans under warming.

Since they can’t do much on the side, And of course, partly due to the melting of glaciers or the melting processes of the great ice shields of Greenland and the Antarctic. These contributions due to the melting of the ice are what makes us more worried about the future,

Because they actually contribute more in the future than this warming. than this warming. The first core message is that global warming is already at around 1.1 degrees Celsius compared to the pre-industrial level. We know where this comes from. We know how much coal, oil and gas we burn.

We know what this does to the CO2 rise. We know that this has a greenhouse effect and we can actually prove it. Very important, we are already at 1.1, 1.2 degrees Celsius. I would like to make a short introduction. This is primarily a lecture on climate change.

But I honestly don’t want to leave the second big ecological problem of our time unmentioned. And that is the species extinction that we are currently causing. I work, on climate change in the history of the earth, especially on the extinction of large masses in the history of the earth.

The difference is that this time it is actually us who are responsible. This has nothing to do with climate change yet, but it will change, as I will tell you in a moment. We are currently experiencing a really, really dramatic loss of biodiversity, such as the destruction and fragmentation of habitats.

Think of the drying up of wetlands, the construction of commercial areas, the cutting of the landscape through roads, rail lines, etc. This makes it difficult for living beings to migrate and react. This is of course a problem in climate change, if they cannot migrate to cooler regions,

Environmental pollution and pesticides play a role. I don’t have to explain that to you. We are exploiting resources. Think of overfished seas and other factors. Invasive species are actually an increasing problem. You are also aware that by globalizing,

More and more species are simply being dragged in and the local species are actually being suppressed. We have an outbreak of insects and pathogenic pathogens that do not belong there and where the local species are not prepared for. There are already examples of species that have died out by climate change,

And in the ocean, the ocean acidification by our CO2 emissions plays a certain role. It’s really pretty intense right now, so many people ask the question, are we on the way to the sixth major mass extinction? The sixth is due to the fact that we have five,

So we had a lot of mass extinctions in the history of the earth, but we had five very, very large ones. And that is essentially an illustration of the biodiversity curve, i.e. the number of species, over the last 600 million years or so. And you see that it doesn’t go up continuously,

But that there are always these incisions that are marked here by the numbers, where large masses actually die out a certain significant part of the living species from the mantle of the earth. The largest 250 million years ago, when large volcanic eruptions led to a drastic warming and acidification of the oceans,

And in principle 90 percent of the species disappeared. So really a very, very dramatic event. A little more known 66 million years ago, the number 5 here, which ultimately eliminated the dinosaurs by far, except for our feathered friends out there, who are the next living relatives of the dinosaurs and have survived.

And the question is simply, are we doing something that is on a similar geological scale? And there are an incredible number of statistics. You can look at it, you can look at it in terms of disappearing species, The numbers are really not nice. We are not quite there yet.

So we have not yet reached the scale of one of the five major mass extinctions in earth history. But that is not really reassuring, I would say. If we don’t change that and especially counteract climate change,

Then we will come to a scale that is actually comparable to these large mass extinctions in earth history. And that is the second message I really want to give you. Climate change is not our only big ecological problem. The great mass extinction that we are currently eliminating is actually a problem too.

Why are we worried about climate change? We don’t care about all of this. Are we enjoying the better red wine that winemaking areas in Germany can produce? It is simply the case that this warming causes consequences, consequences for nature, consequences for us. I will come back to an episode that is already noticeable.

These are weather extremes, heat waves, We have had this repeatedly here in Germany in recent years. This leads to additional deaths, lack of drinking water, This is well known and also statistically proven. The downside is that we actually have more heavy rain events, strengthening of tropical whirlwinds. Not in all world regions,

This is also provable, We have already measured the sea level rise and of course will accelerate it in the future. It threatens the coasts and islands. A significant part of the world’s population now lives on the coasts. That’s the way it is. I mentioned it. At the moment,

We are already causing a dramatic biodiversity loss in the Arctic Ocean. This will actually be strengthened by climate change. We see, for example, cool, loving species are slowly moving towards the summit. But at some point the summit is reached. Then nothing works anymore.

Or a northward hike on the Northern Hemisphere is limited by the fragmentation of habitats and the Arctic Ocean. At some point a limit has been reached. The whole thing has health consequences. We already see that. We have more heatwaves in Germany and in Europe. In the summer,

There are infectious diseases due to flooding disasters. We also have an increasing spread of infectious insects. This also applies to warm-living insects, which then bring in pathogens. If we look at it on a larger level, there are simply so many locations where there are conflicts of resources, also in food.

Dirty events also strengthen and trigger migration movements. I think we have seen in recent years how well we are prepared for this. We see it in the media every day. Extreme events are the climate consequences that are perhaps the most visible.

I want to remember the summer of 2018 and how drastic it was. You have noticed that we had forest fires in many European countries, including near Berlin and near Potsdam. That’s maybe 10 km away from my place of residence. It’s not that I’m endangered by forest fires,

But it all seems a bit unlikable to us. But of course also in other world regions like California. For Europe, it was a summer that was so extreme that it was far beyond all natural fluctuations. You can see it here.

These are land surface temperature anomalies for Europe for the four months from April to July over the last 110 years or so. You can also see that the summer temperatures are increasing across the country in Europe. You can also see that it fluctuates from year to year. You know that. There are cooler,

Rainy summers and hotter, And then there’s 2018. It’s no longer within the natural range of fluctuations, but it’s really an event that’s very pronounced. I’ll get back to that in a moment. We can actually trace this back further. We can use temperature reconstruction methods, tree rings,

We can use these to reconstruct the European summer temperatures over the last 500 years. Essentially, this histogram is shown here as a gray line. You can see that we can name individual particularly cool years.

Here on the left as blue stripes and then of course particularly hot years on the right side of the diagram. It’s a bit striking that they all fall into the 21st century. It’s not really amazing. You might think that this is just a statistical shift. When it gets warmer globally,

This distribution also shifts to the higher temperatures for Europe. You would expect more of it. And that’s actually the case. But if that were the only problem, we wouldn’t have to worry so much. What also happens is that climate change has an effect on the atmospheric circulation pattern.

Especially on a phenomenon called the jet stream, which has even appeared in weather reports in extreme weather events. This jet stream is a fast air flow in the upper atmosphere, which you can see here as this reddish band, this reddish meandering band in this NASA visualization in this beautiful one.

You can see that this jet stream has certain distractions, such as wave-like distractions. This is also the case with the distribution of ozone through mountains, through the current warming. You can also see that this jet stream, if you look at the patterns closely, it slowly moves eastward, But this is important for us,

Because it’s not just a stream in the upper atmosphere. The jet stream influences how high and low pressure areas move. Among other things, What we have found is that we can actually prove two things in the data.

We see that this jet stream has increasingly stronger distractions due to the different warming of polar regions, equatorial regions, perhaps also due to the disappearance of sea ice. That’s one thing we see. And then we have so-called blocking events, where the jet stream does not move so slowly to the east,

But remains stationary. And the same is true for the low pressure areas below. And that’s exactly the situation we had in 2018, where we had almost continuous high pressure influence from April to September. We had very, very few low pressure areas. We just had the jet stream that was there,

And these high pressure areas were there. Of course, it intensifies at some point. At some point it’s so dry that no water can evaporate from the jet stream. But the other way around is that when there is a low pressure area on the other side,

But it’s there and it rains on site and off site. And then they get flooding there. And that’s mainly the change in the jet stream that causes these extremes. I can make a film like this every year now, and I could put a lot of pictures and examples on it.

2021 was another year like this. You may remember the devastating heavy rain events in Germany. At the same time, we had forest fires in Siberia, on the other side of the jet stream, So we actually observe these extremes every year. 2022 wasn’t much better.

I made this film for an older lecture and found that Cologne is of course a wonderful example for the DLR Astro seminar. You see satellite images from 2021 and 2022. And you know the situation better than I do from the satellite images, how the level of the Rhine fell in the last summer,

Which was also relatively extreme. This leads to more deaths. This can also be statistically proven. We just see that more elderly people die in hot summers. This is a serious problem and will get worse. But in the meantime, I’m not a huge fan of economic arguments, but it is what it is.

The summer of 2018 and 2019 together actually caused about 35 billion euros in damage. You know that when the forestry industry or the Farmers’ Association say that we had serious failures of so and so many billions of euros. Ultimately, equivalents. These are exactly the numbers that you can add up.

The floods in the summer of 2021 were taxed at around 40 billion euros. And by 2021, we had actually 145 billion euros on average. Although, as I said, the temperature curve is pointing upwards. The damage is getting worse. That means 0.2 percent of annual economic output. As I said,

That’s not bad at the moment. But it’s not as bad as it was in Germany. That means there are already climate consequences. This is not abstract, There are already climate consequences today. And there are also climate extremes in Germany, especially weather extremes, So nothing that comes out of a computer model.

But that is actually already verifiable today. Now we want to know how this will continue. How does the global average temperature continue? What does the Earth look like in 2080 or 2100? We have two problems. First, we don’t have any direct measurements.

We are of course dependent on computer models to project what it could look like. These climate models are pretty good now. They are not free of problems. Clouds are still a bit difficult to model. They make slightly different statements. But overall, it is robust in terms of temperatures. That’s our first problem.

And the second is that we are not a narrator. We don’t have a crystal ball. We don’t know how humanity will behave in 2060 or 2030 or 2040. Or what technologies we will have available. That means we can only do this under certain assumptions.

That means we can set up certain scenarios for how humanity will continue in terms of population development. How much fossil fuels are used? How much renewable energy is used? How much meat do we eat? What technologies are available to us? We make a few scenarios. Typically five scenarios. There are more.

We cover the range between a further scenario, and these scenarios provide certain emissions of CO2, methane and so on. For the years. We can feed this into our climate models and see how the climate warms up. Two steps. We get an emission behavior from it. We feed this into the climate model.

And then we have a projection for the global average temperature. We have given the global average temperature anomalies relative to the pre-industrial period, the second half of the 19th century. The black curves are the current trend. You see this slight warming compared to the pre-industrial level.

It depends on how you set up the reference period. Then you see, under the assumption of these scenarios, what the future would predict. We don’t do this with one climate model, but with 30 climate models. Climate models have their own characteristics. There are many modeling centers around the world that do this.

You see that for the two scenarios where this is indicated, for this dark blue and this not-so-dark red, there is a voltage. This is the uncertainty that comes from the complexity of the climate system, from our lack of knowledge of climate sensitivity, from the uncertainty of cloud modeling, from model errors.

We can’t predict this precisely. We don’t say we can, It also depends on how the biosphere reacts to warming. We don’t know this precisely yet, because we haven’t tested it yet. All these uncertainties play a role. You see that we have it in our hands.

It depends on us whether we will add another 0.5° or 1° to the global average temperature at the end of the 21st century, or whether we will continue to do so and add another 3° or 4°. I can’t tell you or us. For us,

It is also important how the patterns of warming look like. As I said, the global temperature curve is one thing, the patterns are something else. Up here, it is shown for 1° warming. On the right, there are the modeled temperature distributions for 1° global warming. On the left are the observed ones.

You can see that it is not exactly the same. The models are not perfect, You see a blue spot here, I will come back to it later, in the North Atlantic, south of Greenland. It will play a role. You can see that the basic pattern is always relatively robust.

The continents and polar regions warm up more. This is exactly what we have seen in the observational data. We can see that the global warming is 5°, If the global warming is 4°, and if you look at the absolute temperatures that you will get at 6°,

Maybe with additional warming compared to pre-industrial levels in the tropics, then we also reach temperature regions that influence the habitability of tropical regions very actively by humans. This is our decision. You can see that there are clear differences. Especially in the country regions where we live. In Germany, In Germany,

1.5° and 2° are not half a degree different. In Germany, 1.5° and 2° are not half a degree different. There is a difference of 1 or 1.5° in the average temperature. We live on a land surface that warms up more. This has direct effects on weather extremes.

This has direct effects on weather extremes. We have seen that this is already a factor. You can look at this here. This is a slightly complicated graph, These are the warming levels. 1.5°, 2° or 4°, These are the warming levels. The first thing is that under 1.5° warming,

The heat waves would not be 1.5° hotter, the heat waves would not be 1.5° hotter, but 1.9° hotter, Primarily because the land surfaces warm up more. Global average temperature and local land temperature are still different. The frequency increases. That means they get hotter and more frequent. For 1.5°,

An event that would occur once in ten years without climate change For 1.5°, an event that would occur once in ten years without climate change would occur 4 times in ten years with 1.5° global warming. would occur 4 times in ten years with 1.5° global warming.

A heat wave that we had once in ten years before climate change would occur 9 times in ten years with 1.5° global warming. would occur 9 times in ten years with 1.5° global warming. This is really about the substance. It would be 5° hotter. Imagine that. Imagine that.

The same for events that occur once in 50 years before climate change. It’s similar. It has an influence on whether it occurs in 9 out of 50 years with 1.5° global warming or in 14 out of 50 years or in 39 out of 50 years with 4° global warming.

It’s really something that affects nature, our parents, our parents, grandparents, our children, It’s a massive difference. It’s a clear difference between 1.5° and 2°. Every tenth of a degree is important. That’s my mantra. The same goes for heavy rain events where we see this over-average intensity and frequency.

We’re in a situation where we want to say that the temperatures are increasing. Where do we set the limit? Where do we want to go? 1.5°, 2°, 3°? This is not something that comes from physics. It’s a risk assessment that we have to take. This is because in different areas – for example,

Here are these left-hand color beams – depending on the global average temperature or the increase in the global average temperature compared to the pre-industrial level, the risk is indicated by these darkening color beams. Here on the left, these are unique ecosystems. Coral reefs, rainforests, for example. Then you can have extreme weather events.

Here is the second beam, You can, for different sectors, for extreme weather events, for natural systems, make a risk assessment. You see, it gets worse with the temperature increase. But there is no natural limit. You can’t say that if you apply the Parisian range of 1.5° to 2°,

That everything is fine at 1.5° or 2°. It’s actually a continuum in a way with a few possible surprise effects. But ultimately, it’s a decision that we have to make. Climate factors increase with increasing temperature and I can still come back to potential surprise effects by tipping elements.

A temperature threshold does not arise from physics, but ultimately it is a social and political decision about what risk we are still willing to take or what we can still responsibly do. Ultimately, that is our decision. And it is also the case that at 1.5°, warming above the pre-industrial level or 2°,

Not everything is good. It’s not like there is a cake with eggs at 1.5°. We already have extreme weather events, deaths and damage at 1.1° and species disappear. That’s also the case at 1.5°. At 3°, we are definitely in the red zone. We can now decline that for various reasons. For example,

Sea level rise. I showed the measuring data. Depending on the emission scenario, depending on how we behave in the future, we might get another meter up to 2,100. That’s not a small number. The tricky thing is that our models are definitely underestimating that. We see melting processes in the Antarctic and Greenland.

Ice shafts are collapsing. Faster-flowing glaciers that do not include the models. There will probably be an additional contribution that is not included in the models. And because of the inertia of the system, the warming will continue for centuries. We are clearly shaping the coastlines for thousands of years.

That’s what we are doing today. The fourth message is that climate conditions are increasing and my mantra is “Every tenth degree counts.” We can’t say “We are rising 1.5°, let’s go to 2.10° and if we don’t reach 2°, we will limit the temperature rise as far as possible.” Every tenth degree is important.

Beyond the Paris targets of 1.5° and 2°, we as climate researchers agree that we don’t want to take the risks. That is the background of the Paris climate agreement. After many frustrating international negotiations in the field of climate policy, where nothing happened in 2015, we had a diplomatic breakthrough with a few disadvantages.

We will come back to that later. But the core of Paris is that for the first time an international target was set, a 2° target, to limit global warming as far as possible. And to limit it to 1.5° as far as possible. Unlike earlier mechanisms, all countries are involved,

Not just the industrial nations. The mechanism is not binding, but there are voluntary commitments that are checked every 5 years. The idea is to name and shame. An additional ambition is to overbid with climate protection. A signal is given to the markets, but the countries that don’t comply get an international bad reputation.

That’s how the construction was built in 2016. I’ll show you where we are going. It doesn’t look good. What can we do to achieve that? I won’t tell you a lot of surprising things. It’s natural that we give similar lectures over the years. You probably know that.

We have to reduce our emissions in the different sectors. The electricity sector. We need CO2-free electricity from renewable energies. We have to increase capacity, build wind turbines, build photovoltaics, strengthen the grid and build storage. You all know how well it works in Germany.

The renewable energy law was a success but it’s not good enough. We have industrial production, steel, cars, We have to reduce our emissions. If we need a lot of energy, we can build steelworks with hydrogen from renewable energies. Hydrogen is not a miracle solution for all other sectors.

We can’t do it with renewable energies. The big construction site is the building sector. Many of us live in old buildings that are poorly insulated. We saw it last year. We use a lot of oil and gas. We use gas from countries where we don’t want to use it.

We need emission-free heating and better insulation. You know how controversial it is. You saw it in the media. I know it’s expensive and not everyone can afford it. But we have no choice. We have to do it. Another big problem in Germany is the transport sector.

You know how much money is spent on the railways. After decades of lack of investment in infrastructure, it’s a miracle that trains can still run. We have to do it urgently. A number of ministers didn’t contribute to the solution. We have to expand the railways. We have to use more bicycles.

We can’t replace every car with an electric one. We need mobility concepts that go beyond individual mobility. For certain areas, like freight transport, we need special solutions. We have to do it. I can show you the figures. We are behind in the building sector and in electricity. We have to reduce emissions.

I don’t want to talk about it. But we need to reduce the amount of carbon. That’s for food and meat. It’s good for your health. It’s good for transport. We have to use more regional products. We have to travel far. There have been excesses in the last 30 years.

SUVs and fast city flights to Barcelona or London on cheap flight tickets. It’s not sustainable. We know that. We have to follow the regulations. Many economic models are based on this. We only get emissions by having negative emissions. We have to use some measure to remove CO2 from the atmosphere. That’s not uncritical.

There are approaches to reduce emissions. For example, iron fertilization of the ocean. It’s not tested yet. We might have a technology that will help us. But we can’t wait. We can’t say that we have the technology that will solve the problem. The most critical way to remove emissions is photosynthesis.

If you use biomass and cut off CO2 and compress it in the ground, that’s a method. But you have to remember that the land area is limited. You can’t cut down forests to use biomass. We need land for food production. The potential for sustainable biomass production is limited.

We don’t have much time left. For a certain level of warming we have a budget for CO2 emissions. If we want to keep it at 1.5 degrees, we can do it from 2017. If we have emitted it, we have reached the limit. We have the choice to reduce quickly or to wait.

If we want to keep it at a certain temperature level, we have to reduce it as quickly as possible. We have done nothing for 30 years and we have to reduce it at all fronts. In Germany, in the building sector, in renewable energy,

We could have done it more relaxed if we had started 30 or 40 years ago. We see this in the emission development. Here is the energy industry, electricity production, the industry, the building sector, agriculture, and green. Our emissions are decreasing, but not as fast as we should.

There are sectors where we see increases. But we can’t make any progress. This is far from what we should have in 2030. It is not so long ago. For Paris, we would need 0 emissions by the middle of the century. The time to the middle of the century is relatively fast.

The reduction of emissions is very slow. Germany can’t solve this problem alone. But Germany has a responsibility. 1% of the world population is responsible for 2% of global emissions. Of course, but that doesn’t solve the problem.

We are in 6th place in terms of current CO2 emissions in countries and 4th place in terms of emissions. We have a historical responsibility for climate change. Ultimately, it is in our own interest to think of climate-friendly technologies that we want to sell. We don’t have much time.

If we want to be at 0 emissions or have a chance to stay at 1.5 or 2 degrees, we have to do something. Globally, it doesn’t look good. Too little, too late. These are global emissions. All greenhouse gases are CO2 equivalents. The green would be something that would be compatible with 1.5 degrees.

We would have to go down quickly. The blue area is implemented in terms of climate protection measures. We are somewhere between 2.5 and 3 degrees in terms of warming compared to the pre-industrial level in 2100. If you think of the extreme events or the climate effects,

We are definitely in an area where we don’t want to go. The goals for 2030 look a bit better. But we saw for Germany how far we are away from them. In terms of emission reductions. Even in an optimistic scenario, we would probably end up at 1.8 degrees.

But we are by far not on the way here. We are on the way to 3 degrees. Or 2.5 to 3 degrees. Nothing happens. After the first climate reports. In recent years, there has been a lot of movement in Germany. Fridays for Future has done a lot.

I would like to ask you to support your children and grandchildren who have to go to the bathroom at some point. It is nice that not only students are walking on the streets. It was a very broad social layer that actually tackles the problem. In some cases,

As certain parties in the federal government. The second glimmer of hope was the judgment of the Federal Constitutional Court. The court said that what we are doing today limits the freedom of future generations. This is something that politics will have to let itself be measured. Hopefully still in the future. Fifth message.

We can prevent the worst. But 1.5 degrees is hardly possible. We are so close to that. Finally, There are parts of the earth system that can show non-linear behavior due to positive and self-enhancing feedback. The system state changes very suddenly. Even if the temperature changes very slightly.

We have a sudden change in the system behavior. There are a number of them. I will introduce a few of them. With some, you can debate whether they are tipping elements or whether they are irreversible or reversible. I don’t want to go into the debate.

We understand many of them to a certain extent. But we can’t quantify the tipping point. There is a certain uncertainty. You can see that in this graph. For different tipping elements, for example, ice on Greenland, the risk of global temperature rise relative to the pre-industrial level, when these colored bars are indicated.

If you look at the 2 degree Paris threshold, which is also indicated here, the 1.5 degree is actually only shaded. You can see that there are some tipping elements that are actually risky at 1.5 degrees. Or at 2 degrees. But beyond 2 degrees, This is 2 to 3 degrees.

This is not even the Paris area, I want to introduce a few of them. One is coral reefs. This is the third bar on the left. At 2 degrees, At 1.5 degrees, Coral reefs are no longer salvageable at 2 degrees. The tropical coral reefs. Cold water corals and individual fragments.

But the problem is, depending on the global temperature rise compared to the pre-industrial level, how many percent of the coral reefs are affected. At 1.5 degrees, somewhere between 70 and 95 percent of the coral reefs are affected by bleaching. At 2 degrees, all climate models agree that the thing is actually over.

At 1.5 degrees, we lose a large part of the coral reefs and at 2 degrees, they are probably gone. Permafrost around the Arctic. You can see it in the press from time to time. The problem is not only for the infrastructure, but also for methane release, strong greenhouse gas. Here, too,

At 2.5 degrees, there is a risk of sudden melting events triggered by local summer warming and the larger risks come from the ice shields. The large ice shield on Greenland, if it were to melt, the sea level would rise by 7 meters globally. That’s another size order. It would take thousands of years,

But it would happen if we had hit it. We are already at 2 to 3 degrees in the red area and that is no longer preventable. That would actually affect the coastlines for thousands of years. There are two reasons for this. One is the ice albedo recoupling. When it melts,

It gets darker and absorbs more sun radiation. The other has to do with the thickness of the ice shield. Because the ice shield is so thick, the upper layers are in cooler atmospheric layers. If the ice shield is too thick, it would slide into warmer atmospheric layers. The melting would increase accordingly.

Similarly to the West Antarctic, at 3 degrees we are already in the red area. Not the entire Antarctic, but the West Antarctic area. That’s another 5 meters of sea level equivalent in the long term. There are also changes in the warming ocean.

That’s another 5 meters of sea level equivalent in the long term. There are also changes in the warming ocean. There are a number of tipping elements where the risk increases beyond 2 degrees Celsius. Without being able to quantify it. Without being able to quantify it. For ocean circulation in the North Atlantic,

The Gulf Stream System is actually quite important for us. As a source of heat, Because part of the drive is cold, salty water that is denser and sinks deeper. If we pour fresh water into the North Atlantic, it could break off. That has happened several times in the history of the earth.

It’s not an abstract risk, It happens due to the increase in precipitation and by melting water from the polar region. In the climate models, it looks very stable. If we look at the temperature data for warming over the 21st century, we see this blue spot again.

You have seen it before in the observed temperatures at 1 degree Celsius. This is a signal that the environmental movement in the North Atlantic, has actually weakened. Because it transports heat into this area. This is the sixth and penultimate core message. We are almost at the end of my lecture.

There are also these surprise effects. The risk of more dramatic climate effects by tipping elements increases by 1.5 degrees or even 2 degrees. It’s a risk assessment whether we want to go into this or not. So that the whole thing is not so gloomy,

Even if I have to draw an honest picture here, I can’t protect you from uncomfortable truths. It is important not only to be afraid, but also to see the whole thing positively. Climate protection is not only good for the climate.

If you think that it is still the case that many people suffer from cardiovascular diseases or lung diseases because we burn fossil fuels. There would be fewer diseases and deaths from air pollutants if we didn’t do that anymore. This sentence has not been here since … since a year.

A lower dependency on energy imports from totalitarian states. We have learned very painfully that this can be a problem. More livable cities. There are still enough cities that are built for cars and not for people, A healthier lifestyle. If you ride more and eat less meat, you will have less problems.

You have already noticed, I am not a big fan of economic arguments. But in the end, we will not earn money as an industrial nation in 10-20 years. We don’t do that anymore. At some point we just have to change the direction. My seventh and last core message.

We have to live on the costs of nature. And finally, secure a livable future. Thank you for your attention. We are open to questions and discussions.