Arktische Methan Speicher beginnt sich zu entladen

• Thomas Reis am 04.11.2020 um 10:57

Ein paar neue Daten zu dem Harvard Albedo Projekt meer:reflection. Das Problem ist ja bekanntlich, das wir laut IPCC CO2 aus der Atmosphere entfernen sollten. Wir haben hier ein 3 Dimensionales technisches Problem wenn wir die Entcarbonisierung der Ozeane(! ist ebenso wichtig) und der Atmosphere betrachten. Wenn wir aber auf das Thema auf einen 2 Dimensionalen Spiegel herunterbrechen, dann ist es viel effizienter.

Prof Dr Tao rechnet mit etwa 10m²(100 sqft) je Spiegelfläche für eine Tonne CO2 je nach Region. Um ein Jahr CO2 Emissionen zu neutralisieren ist etwa die Fläche von Belarus notwendig( 207,600 km²). Es könnte noch Platz gespart werden, wenn wir die Neigung der Spiegel je nach Region optimieren, jedoch sind die Berechnungen dazu noch nicht abgeschlossen.

Die Alternative ist mit Atmospheric oder Oceanic Carbon Capture. Hier ist das Problem das entropische Mischung der Atmosphäre umzuwandeln. Grob der Primär Energiebedarf von mindestens einem Jahr um ca. 200 ppm(?) aus der Atmosphäre zu ziehen. Jedoch ist diese Zahl theoretisch und die Effizienz wird bei eher 5% liegen. Was etwa 20 Jahre an weltweiter Primär Energie entspricht! Was nach sich vordergründig nach wenig anhört aber alleine 1% vom globalen Primärenergie ist enorm viel und es würde vermutlich Jahrhunderte dauern. Auch ist nicht klar wohin das Gas speichern? Und wenn wir es solide machen, dann brauchen wir noch mehr Energie.

Daher sollten wir uns Gedanken zu Spiegeln am Meer machen. Auch ist das Platzieren von Spiegeln am Meer hoch effizient, da das Meer extrem wenig Wärme reflektiert. Ich würde versuchen diese Spiegel mit Photovoltaik Strom zu finanzieren. Aber zumindest müsste Albedo ein CO2eq also CO2 Einsparungs Equivalent oder CO2 Zertifikat bekommen. Heißt auch helle Dächer würden eine Prämie verdienen.

• Jost Kremmler am 04.11.2020 um 20:55

Bei Spiegel online gibt es eine hochkarätig besetzte Konferenz zum Klimaschutz, ab der 57. Minute spricht Luisa Neubauer mehrere Male:
https://www.spiegel.de/wissenschaft/klima-konferen...

• Thomas Reis am 05.11.2020 um 11:13

Ein Entwurf zu einer Transkription aus einem aktuellen Interview von Dr Tao vom Harvard meer:reflection projekt: First take a step back. We have a planetary problem. Enough material to make impact. Most abundant elements on earth si, o and al. engineering in leveraging these materials. Address most efficient most emergency problem. Certain heat trap that allow us to grow and prosper, too much compared to pre Heat arrives and leaves. First of all we look on the possible solutions. (inlet vs outlet) Traditional we try to open(close) the outlet the IR radiation by trying to draw down the IR by cleaning up the atmosphere. That is a very ores(ore) process and very energy intensive. You can achieve the same effect by closing the inlet, by rejecting a portion of incoming sunlight back into space. That is the basic idea of meer:reflection. From the conceptional point of view. When we try to reject light using mirrors, it is a two dimensional engineering Problem because light reflection happens on a two dimensional plane. that is rather manageable compared to a 3-Dimensional volume of the atmosphere and the Ocean we need to sip through and filter. So this is a much bigger operation From the engineering practical point of view. First of all we look at the two possible solutions the inlet vs outlet. And to select one that is most simple conceptional and in practice. A 2d problem versus a 3D problem. And then we look to the abundance of materials we have on earth to implement such a strategy. Which is to make Glass made of Silicon and Oxygen and with a thin film of aluminum. you need only 10-100 nm Aluminum Coating to achieve 80-90% Reflectivity. To give you a idea how big this is, your cell is 10 micrometer. And the thickness you need is 100th of your cell. So by compressing a 3d problem into a2d problem we achieve significant cost and material savings. This makes meer:reflection affordable and scale able. Advantages installing Mirrors on the land an on the water. What is the best strategy to apply. Mrors are just a piece of glass you put outside in your backyard and laying horizontaly. So assume we encourage everybody to buys some mirrors nd lay them in the backyard. Which country a blessed with the highest efficiency. As expected are equatorial regions tropics are better places. But it turns out the ocean are much better. In general the reason is the amount of heat or light available for rejection is the difference what is coming down minus(!) what is absorbed by the ground or the ocean. The oceans have a very low Albedo so you intrinsically very little light is reflected away. So you have a lot of potential to reject. Enormous amount of light by putting mirrors into the ocean. But of course by a practical point of view, it is more difficult to make mirrors float in the ocean, so it is a more involved engineering challenge. But you get roughly a factor to 2-3 improvement in Cooling efficiency when the mirrors are implemented into the oceans, compared when they are laid out into someone’s backyard.
How much Surface Area do we need?
Calculations showed you need roughly 10x10ft 8x8ft square of horizontal mirror layed out in the sunny areas of low albedo to offset one ton of CO2. So that is roughly 100sqf to offset one ton of co2. Average roof space of a person will be around a couple of hundred sqft. That shows when all roofs and Backyards where covered with mirrors. We can offset only months or years and this is obviously not sufficient. While the concept works it is a transition step towards a mirror enabled energy production. So as the emissions go down we need more mirrors. (more renewable production of energy less Dimming) So we talked about horizontal mirrors, so also possible to increase the efficiency of mirrors by toting the mirrors toward angle that the sunlight is arriving. So that calculation is ongoing and could lead to a factor of 2-3 saving in space. The area to need to be covered on annual basis, assuming form the 2019 CO2 emissions rates. Would be the surface area of Bellaruse. Per Year! This area is to compensate the emissions per year. When we want something like to reduce emissions or carbon neutral.
Difference between Carbon sequestration?
Carbon sequestration is to open the outlet by removing GHG.Closing the inlet are mirrors Carbon sequestration works the best from concentrate emission sources for example coal fired power plants. When we allow to escape CO2 into the atmosphere and freely mix, the process is called entropic mixing. Basically it takes work(energy) to sort it back. It is easy to mix gas but it takes energy to reverse this process. Calculations how much energy it takes to reduce to save CO2 concentrations is more than the world consumes in primary energy per year and that is the theoretical number! Any thermodynamic engine or process is never 100% efficient and our current technology would only enable of 5% efficiency. Which means 20 years of worlds Primary Energy consumption is necessary in order to capture CO2 from the air. That is a huge problem it is even difficult to spend only one 1% of the primary energy consumption and 5 % is even harder to do any mitigation efforts. Which means we are looking into timescales of centuries if we entertain the idea of direct air capture. That is why the only efficient way to carbon capture are concentrated sources of CO2 from for example coal power plants. But the problem is once captured where do you put it. Does not seem to be likely that we ever find enough space for even one year of CO2 to store. So when it comes to carbon capture, it is possible but it is not really feasible to store it. That is why people are looking into ways to store CO2 in solid forms. by mixing it into concrete or into giant reactors to transform it into rocks to undergo a geological transformation. The problem to these schemes that they are not scale able into what is necessary, regardless to the amount invested.