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Metabolic Modelling and Synthetic Biology  There are also a number of innovative

research measures that can help save a lot of carbon dioxide in the longer term.

Bioinformatics can help optimize these processes using metabolic modeling and synthetic

biology. For example, green plants fix carbon dioxide from the air using the enzyme

Rubisco. This enzyme is from an ancient time (two billion years ago) and is, therefore, a

little too sensitive to oxygen. It is now possible to try to replace this set of enzymes with

alternative, better signalling pathways that are not sensitive to oxygen. New artificial

enzyme cycles by Tobias Erb are particularly promising in this regard, which together can

then replace Rubisco (e.g., CTECH cycle; Schwander et al. 2016). A slightly older paper

from the USA gives a general overview (Bar-Even et al. 2010). There are also specific

bioinformatics approaches to such metabolic design tasks (Lee et al. 2014). For example,

coupling the CTECH cycle with a glycolate transport mutant that prevents the loss of car­

bon dioxide through light respiration theoretically results in a five-fold improvement in

carbon dioxide harvest from the air (overview of this and other possibilities in Naseem

et al. 2020; first experimental tests in Roell et al. 2021). 

Global Cooling (“Nuclear Winter”) – Possible Climate Consequences of

Nuclear Warfare

These are comparable steps to the simulation of global warming. The main problem in a

nuclear war is the climate impact. Soot and dust from destroyed cities penetrates into the

stratosphere and changes the climate there by a general cooling of four degrees Celsius

over about 10 years, which would lead to worldwide crop failures and hunger.

Climate Simulations  Distressingly, even the replacement of about 100 nuclear weapons

can cause significant global cooling (Mills et al. 2008). Whereby this will not always be

the case, if not too many cities burn down with a big firestorm, because then the soot is

only transported up to the stratosphere. The ozone layer, on the other hand, is always

attacked when so many nuclear weapons are used. Again, this leads to skin cancer and the

death of food crops and, again, worldwide famine. Although climate models are of course

only approximations, there are now already a number of models and scenarios that make

it very likely that these models are right in principle and that nuclear disarmament is urgent.

Overpopulation

Here, there are different models to model population growth.

Modelling with Scenarios  The calculations show that the best results are to be achieved

by rewarding environmentally friendly behaviour and consistently expanding helpful tech­

nologies (Hatfield-Dodds et al. 2015). This works better than dirigiste approaches or social

re-education etc. A global solution (“Plan B”; Brown 2009) can only be a coordinated

strategy that restores the Earth’s so-called carrying capacity via education, more rights for

women, family planning, equitable distribution of resources, sufficient and good job

opportunities, but especially sustainability in agriculture, energy production, manufactur­

16.2  Model and Mitigate Global Problems