SPICE tethered balloon

By Claire

Last night I went to a really interesting seminar at ANU, given by Dr Hugh Hunt from Cambridge University titled, “Is Climate Engineering Feasible?” What I particularly enjoyed about this seminar, was that Dr Hunt approached the topic of geoengineering (or “climate engineering” if you prefer) from a completely different angle to anything I had heard so far. He started the seminar with this analogy (paraphrased):

Geoengineering is like chemotherapy. You’d never wish it upon anyone. It’s really quite horrible, since your hair falls out and your organs start to fail. But, if someone has cancer, it’s a useful treatment. Although we don’t want to have to use chemotherapy, we research it, so that in the case that it is required, we know what it involves, it’s relatively safe and we can be confident in applying it. Geoengineering is the same. It’s a last resort option, but it’s important that we research it, so that in the case that we do have to use it, we know what it involves, we know if it’s safe or not, and we know how to apply it. 

Geoengineering ideas

Now, the whole notion of geoengineering is quite a controversial one. Geoengineering, for those of you who are unsure, basically involves engineering a “solution” or at least a temporary fix to the issue of climate change. Some suggestions for ways we can geoengineer the climate include carbon sequestration, where we collect the CO2 from the air, and bury it deep underground, effectively removing it from the carbon cycle, ocean fertilisation, where the oceans are “fertilised” with iron (a limiting factor in plankton growth), allowing more plankton to grow and absorb CO2, then die and sink, taking it down to the bottom of the ocean, or planting trees, to name a few. Each of these solutions removes carbon dioxide from the atmosphere in an attempt to reduce the overall concentration of CO2.

Now, these solutions are thrown around quite frequently as viable solutions, in the future, for removing CO2 from the atmosphere. Dr Hunt pointed out, however, that once you start to think practically about these options, it turns out that they’re not viable at all!

Global-CO2Since the industrial revolution, we have added approximately 35 billion tonnes of CO2 to the atmosphere. If we want to bring CO2 levels back to natural levels (i.e. before we started burning copious amounts of fossil fuels), we need to remove 35 billion tonnes of CO2 from the atmosphere. Now, it’s difficult to grasp just how big 35 billion tonnes is, so lets put that in perspective. Globally, the world’s iron ore production only equates to about 1100 million tonnes. Globally, the world’s coal production equates to only 7.8 billion tonnes. Effectively, to remove 35 billion tonnes of CO2 from the atmosphere would require the development of an industry larger than anything we currently see today.

Not only is the sheer volume of carbon dioxide removal beyond comprehension, the actual techniques proposed turn out to be quite ridiculous when you do the sums.

What this leaves is so-called “Solar Radiation Management” techniques. These include a number of things, aimed at reflecting sunlight away from the surface of the Earth, before it can contribute to warming, including putting giant reflectors in space, injecting aerosols into the stratosphere or painting roofs white.

This is the area that Dr Hunt is actively working in, specifically, in researching the viability of injecting aerosols into the stratosphere  to reflect sunlight back into space. He is working on a projected called the SPICE project – Stratospheric Particle Injection for Climate Engineering (kelly has already written a great post about the specifics of this project). In a nutshell, this project involves investigating the viability of building a giant tethered balloon, fed by a pipe from the ground, to inject aerosols into the stratosphere.

Mount Pinatubo erupting in 1991
Mount Pinatubo erupting in 1991

Now, I realise how silly this sounds, but actually, when you think about it practically, it is the most viable geoengineering option available. It is both affordable (in terms of global budgets) and effective (we know that stratospheric aerosols will cool global climate, because we have seen it following large volcanic eruptions, including Mount Pinatubo in 1991). What now needs to be seen, is whether it’s a practical option – can it actually be done?

Dr Hunt had another great analogy as to why it’s important to actually begin to research the viability of geoengineering options:

Imagine that you wanted to put a whole AFL team into a VW Golf (essentially, 22 people into a very small car). Now, you’ll quickly find out that 22 people can not fit into a Golf easily. So what about if you make them as small as possible. Let’s put them all in a blender, and see if we can pour them into the car. Even if you make the most use of space possible, you’ll soon find out that they wont fit – your AFL smoothie just overflows once the car reaches capacity. Therefore, you can conclude that it’s not possible to transport an AFL team in a VW Golf.

Once you’ve determined that it’s not possible, questions like, “How much will it cost to transport the team in a VW Golf?” or “Will they be able to get to the game on time?” don’t matter. It’s irrelevant because it’s not possible to do.

That’s Dr Hunt’s view on geoengineering research. Before we all start to have a heated debate over whether geoengineering is ethical, or cost effective, we need to know if it’s possible. If it’s not, then the argument is void.

Now, I’m still not sure where I stand on the issue of geoengineering, but I agree, that we at least need to know if it’s possible before we start arguing about if we should.