Question

The year is 2020 and the Conference of the Parties (COP26) is taking place in Beijing. Nations have finally conceded that it is no longer feasible to limit global temperature rise to 2°C by means of existing approaches based on mitigation. An alternative response to global warming is needed and three options are being discussed:

Adaptation

Geoengineering based on carbon dioxide removal

Geoengineering based on solar radiation management

Which of these do you believe should be given priority? Justify your answer.

PLEASE DO IT IN COMPUTER

Answer 1

Geoengineering based on carbon dioxide removal should be given priority because these strategies deal with the root causes of climate change and involve reducing the amount of carbon dioxide already in the atmosphere (different from reducing the amount of carbon dioxide emitted). One method involves capturing carbon dioxide from ambient air, compressing it and storing it in geologic reservoirs (usually porous rock or depleted oil wells). However, at this point in time this strategy is considered too expensive to be cost effective.

Another strategy, known as Ocean Iron Fertilization, involves adding iron to the ocean in order to increase algal blooms. These blooms consume carbon dioxide as they grow, and when they die, they sink to the ocean floor, effectively sequestering the carbon. However, this method is highly controversial, because it is not known how long the carbon could actually be stored for, or the negative impacts it could have on the ocean ecosystem.

An approach similar to this involves adding minerals like calcium or magnesium oxide to the ocean. These minerals react with acidic carbon dioxide, and increase the ocean's capacity to hold and store carbon. Another benefit to this method is that it also helps to reduce ocean acidification. However, as with all CDR strategies, there has been little research into long term effects.

CDR strategies are generally not the first ones considered by those who are interested in the use of geoengineering. These strategies are thought of as needing to occur on a very large scale over a long period of time in order to actually be effective. For this reason, they tend to be very expensive and not a viable option at this time.