Climate change – still hope?

This is the question explorer and conservationist Tim Flannery attempted to answer, at the RSA today.

Tim Flannery and Sir David Attenborough
Tim Flannery (left) and Sir David Attenborough


“We are producing emissions at the highest rate we could have imagined a decade ago,” he says.  We have already reached 1degC of warming since pre-industrial times and with what we have already emitted, because of the lag effect, we are committed to another 0.5degC.

“At 1.5degC there won’t be a Great Barrier Reef,” he said.  “Are we prepared to live in a world like that? If not, we need to work on techniques to take the co2 out of the atmosphere.”

So, what would we have to do to remove co2 naturally, he asked? The answer is to plant an area of trees the size of Australia.

We can’t hide from the reality, he said:  Nobody expects we can stop at 2degC by cutting emissions alone.

One solution which had been much touted is geoengineering, and indeed there is already active research going on in the field in China. But this is an inherently risky route and there is no global treaty regulating geoengineering. “My great fear is that a nation will go it alone when things get bad.”

So, if not geoengineering then what?

I used to be pessimistic, he said, but it had become increasingly clear there was a third way involving technologies which can draw large volumes of co2 out of the atmosphere. “They are not ready yet but we need to start now. We know it takes decades from our experience with technologies like solar and wind.”

There are several promising pathways Flannery outlined:

1. Biological. The trouble with biological approach is that they are limited in the face of the scale of the problem. Flannery says we would have to look to the sea where growth rates are much higher and pressure on space much lower. He pointed out that with  9% of the ocean as sea weed farms we would draw down all our current annual emissions of co2. However, he points out, that would actually result in sea weed farms covering an area five times as big as Australia. Nevertheless, there is valuable research in this area making good progress.

2. Chemical pathways. The main problem with these generally is that they need energy which doesn’t make sense until we are making enough clean energy.

That said, there are very interesting possibilities, he believes. One promising avenue is making carbon negative concrete, for example. This has already been produced experimentally and is very attractive as concrete is a major source of emissions.  But, he says, the construction industry is sceptical and is unlikely to take it up until the technology is proven. This is an area where the economic incentive of a carbon price would, he believes, drive uptake.

Another interesting area is to use silicate rock which naturally absorbs co2 when it weathers. For example, we could mine rock, grind it up and put it on beaches as sand.

Another promising research project is making plastic directly from co2. What about the havoc caused by waste plastic, asked David Attenborough? “Plastic is an appalling hazard to wildlife – we have to do something about that.” Flannery agreed.

One project Flannery was particularly enthused by was making carbon fibres directly from co2. This was exciting, he said, as it was claimed this would be cheaper than conventional methods of production which would mean carbon fibre could compete head on with steel and aluminium, both of which are major emitters. It was likely, he thought, that private money would fund this development as the rewards are potentially so great.

He then turned to carbon capture and storage (CCS). The traditional approach which was designed to make coal fired power stations “clean” was, he said, a failure. “It’s very expensive, very complicated, and doesn’t even capture all the emissions.” Will the price of renewables tumbling this would never make economic sense for coal.

However, this is not to say that CCS generally shouldn’t receive R&D effort. Where could we store co2, he asked rhetorically? Two options at least  – 3km down in the water  where the pressure makes co2 solid. Another options being explored was to bury it the antarctic – chiller boxes powered by wind would turn co2 to snow which could then be buried.

If this all sounds like science fiction, Flannery says we need to “keep the imaginative pathways open”. 2050 will be very different to 2015, he says. “Think of the difference between the world in 1915 and 1950.”

The key point is, he argues, that we have to cut emissions now and hard as well as start researching seriously on these technical solutions. If we continue as we are we will be out of budget in 13 years. And one of biggest risks of 2degC is a large release of methane which could spike temperatures. For this reason we can’t afford to wait before cutting emissions hard, but, because there is a lag between emissions and temperature increases we have a chance to develop solutions which will take co2 out of the atmosphere.


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