Blog 2022-01-15 - Thoughts on climate change - is mankind guilty?

(light mod. 2022-01-26).


It's about guilt, maybe responsibility, definitely guilt.

It's about climate change. A climate change largely caused by humans. The "human cause" can be proven very clearly ...

But that's not the point at the moment. Whoever is to blame, we - the people, and only we the people - must reverse climate change. One possibility might be renunciation. Not driving, not eating meat, and much more. But it doesn't look as if people's hunger for energy will be curtailed. Renunciation is honorable, but I fear we must also renounce that honor. At least largely. I'm not saying that we shouldn't practice conserving energy.

But it is not enough to practice renunciation. We need new technologies - technologies that are free of fossil fuels: Photovoltaics to generate electricity, "machines" that produce "green" gasoline, wind energy for the electricity hunger and much more. But we also urgently need technologies that will enable us to remove CO2 from the air. Nevertheless: we also have to produce less CO2 and fewer other greenhouse gases. We can "compensate", i.e. "capture" the emitted CO2 again. But it is not that simple!

Planting trees, renaturing dry moors, all of this is a method of compensating – methods that are strongly favored at the moment, but as far as trees are concerned, they can burn and we have gained little, maybe nothing at all. The devastating forest fires worldwide and this century in different parts of the world show that it seems almost too late. A planted tree stores CO2 due to pho40 tosynthesis. One tonne of wood stores (roughly) one tonne of CO2. But only until the wood has been burned or rotted away. A zero-sum game in the long run. And there may not be enough peatlands to significantly affect the climate.

So we have to get the CO2 out of the air faster than it comes in. And we should only do that up to a certain limit. Because when there is no more CO2 in the air and no other greenhouse gases either, then the earth becomes a lump of ice, as has happened several times in the history of the earth when there was a so-called snowball earth. Quite apart from that, our plants need the CO2 to grow! The CO2 reduction limit should be around 280 ppm CO2 or CO2e (this is the actual climate gas value, which includes the other climate gases such as methane, socalled-CO2 equivalents). Possibly a bit more than that because it is rather difficult to reduce that gas at the moment. About 40 - 50 Gt of CO2 are generated annually by mankind.

There is also a fundamental problem here: If there should one day be a biologically effective method for getting the CO2 out of the air relatively quickly, such as improved photosynthesis, as discovered on a laboratory scale at the Max Planck Institute in Marburg (CETCH cycle), then do we have a chance. An internal publication of this institute spoke of a 20-fold effectiveness of this cycle compared to natural photosynthesis.

If this is successful, then care must be taken to ensure that the process is implemented fairly quickly on the one hand, and on the other hand that this process can be strictly controlled so that the 280 ppm limit is not exceeded.

The authors of this study (including Prof. Tobias Erb from the MPI for Terrestrial Microbiology) also believe that this could make it possible to create more food for a growing world population: Erb says that he and his colleagues hope to further expand their facility and modify the process in order to make other organic compounds that are even more valuable than glycolate, such as drug molecules. They also hope to convert captured CO2 more efficiently into organic compounds that plants need to grow. That would open the door to manipulating the genes for this novel photosynthetic pathway in crops to create new varieties that grow much faster than current varieties - a boon for agriculture in a world with a booming population.