Why we shouldn’t use geoengineering

As we all know the global climate has been altered and continues to be altered through human impacts. This has led to an average increase in global temperatures, more extreme weather events, and other impacts such as ocean acidification. These impacts were first officially acknowledged through the formation of the Kyoto Protocol in 1992, an international treaty committed to reducing greenhouse gas emission.

The Paris Agreement in 2015 is another notable milestone in international climate change action, with multiple commitments to affirmative climate change policies.  These nationally determined contributions (NDCs) are required to be reported on regularly, with a global evaluation every 5 years. The glaring issue with these international agreements, however, is they have no backbone; nations can pull out whenever they choose, and there is no ability to enforce these NDCs. This begs the question, can we as a species meet global emission reduction goals to meaningfully reduce the harmful effects of climate change, and furthermore, can we do it in time?

On the surface, geoengineering may appear to be the solution to these questions; providing a quick fix alternative.

Firstly though, what is geoengineering? It is a rather broad term used to describe forced alterations in the Earth’s climate system by us humans.

How is it achieved?

Geoengineering can be broadly split into 2 main groups: atmospheric/space-based solar radiation reduction, and carbon dioxide removal methods closer to home. The most commonly referenced method of geoengineering is that of stratospheric aerosols.  Specialised aerosols are proposed to be injected into the stratosphere, with radiation reflecting capabilities. This aims to reduce the amount of solar radiation (sunlight) reaching the Earth’s surface and thus helping to cool the climate. It is theorised such methods could be effective in reducing temperatures within months. Other forms of geoengineering can be seen in the figure below.

Sourced from Climate Central at http://www.climatecentral.org/gallery/graphics/geoengineering_schemes

Technical problems

The most noticeable problem with solar radiation-based geoengineering methods is they do nothing to combat emissions and the elevated levels of CO2 in the Earth’s system. This means processes such as ocean acidification go unchecked while creating a massive carbon sink. If geoengineering was to be halted once started, the CO2 would once again be released into the atmosphere and rapidly accelerate warming. There is also the barrier of costs and technological advancements. Delivery methods of the aerosols include weather balloons, artillery guns, and even a space elevator, with each method estimated to cost billions each year.

Perhaps the most damaging aspect of geoengineering, however, is one most would not consider. The mere existence of geoengineering as an option can shift attention and resources away from meaningful methods of emissions reductions such as clean energy technologies. Why invest in such technologies when a fail-safe seems to exist if things eventually get “too bad”? I propose some parting food for thought. Which sounds more appealing to a politician with a fixed term and growing public pressure to show results; a technology that can provide noticeable results in mere months, or a commitment to reductions, the climate results of which won’t be noticeably felt until long after their term is up.


9 Responses to “Why we shouldn’t use geoengineering”

  1. Marco M. says:

    I was not aware of these short-term alternatives! But as you said it would mean at most a temporal solution. Interesting post!

  2. Jasmine Rhodes says:

    This is certainly a divisive topic! I too am of the hope that we can combine mitigation and adaptation strategies to avoid something like this.
    As far as I know, even if there was no technological barrier, there would still be near insurmountable political barriers to implementation of such a strategy. Imagine the level of cooperation that would be required for such a thing…I sure don’t think it’s likely (which is fine with me!).

  3. Vebronia Solo says:

    I had this topic in my Graduate Seminar class. We discussed a journal evaluating costs and available technology for implementing bioengineering. Personally, I consider possible risks that might happen and I am still worrying for its effectiveness.

  4. randersen says:

    Hey Flora, I didn’t know that! I’ve read 1.7% of all incoming solar radiation would need to be reflected in order to bring temperatures back to pre industrial levels, seems like a pretty precise target to aim for on a global average. Did they mention whether they consider aerosols to be the most viable method?

  5. randersen says:

    Thanks for the comment Stephen! It is somewhat comforting to know if we do screw up monumentally with emission reductions we still have some potential alternatives, even if they’re not ideal.

  6. randersen says:

    Hey Ben! I’ve read a bit into it, currently sulphate aerosols seem to be the go-to method. The main barrier seems to be delivery methods, with planes seeming to be the most cost efficient. There’s been discussion regarding the formation of ideal droplet size which goes hand in hand with the delivery. We’d also have to forgo our blue skies 🙁

  7. Stephen Yao says:

    That’s really an interesting post, thanks for sharing!
    I had a curriculum called Atmospheric Chemistry last semester, I learned a lot about this. The global warming is a big issue and there are a bunch of ways that scientists came up with to cool the planet. Aerosol is one of it, aerosol has its own benefits but too many potential risks in it. Overall, as you said, aerosol(geoengineering) may not be a good idea.)

  8. Benjamin Andrikopoulos says:

    Interesting concept. Have you read much into the proposal of shooting sulfur dioxide (SO2) into the stratosphere to cool the Earth? It’s actually made to mimic what happens after a volcanic eruption. Give it a google if you’d like it’s an interesting argument.

    But great article!

  9. Flora Norton says:

    Really interesting topic – I’ve read a lot about geoengineering because I find it such a confronting prospect! But did you know that most scientists think we’ll have to start using it by 2050 despite the consequences if we want to keep below 2C! Pretty worrying