Reducing CO2 not possible

From Almuth Ernsting 20 June

sorry, not a response to your question about C&S versus C&C. However, what concerns me is that a lot of people seem to be adopting the 350 ppm 'target', probably without giving much thought about whether reducing atmospheric CO2 is possible and what might happen to life on earth if we try.

1. Reducing atmospheric CO2 concentrations is not the same as stabilising them. Carbon rationing is about trying to stabilise CO2 concentrations. Carbon rationing is about doing as little further harm to the planet as possible.

2. There is currently no known mechanism for reducing atmospheric CO2. Every molecule of CO2 that we add to the atmosphere will stay there on average for 30,000 years.

3. Attempts at reducing atmospheric CO2 levels, particularly those put forward by James Hansen (explained below) involve dangerous experiments at planetary engineering, which have the potential to accelerate and intensify the climate and extinction crisis which we are facing.

4. There is just a chance that, in decades to come, somebody might invent an efficient way of air capture of CO2 which won't use vast amounts of energy, nor require vast areas of land. As James Hansen and the IPCC report state, such technology does not currently exist and is a long way off, if it ever will work. This is why James Hansen has not incorporated it into his proposals.

5. What Hansen is speaking of, and what 350.org and Beyond Zero Carbon appear to endorse is that we can cool the planet by converting vast areas of land to biomass plantations and somehow sequestering the carbon. It involves 500 million hectares of monocultures coupled with either CCS (of which not a single full-cycle demonstration project exists), or by making charcoal and digging it into the ground (biochar). There is no evidence whatsoever that the carbon in biochar will actually stay in the soil for any length of time (leading soil expert and biochar proponent Johannes Lehmann of Cornell University has confirmed this to us).

6. Agrofuels have turned out to be a major disaster - significantly accelerating global warming. With the James Hansen proposals, think of today's agrofuels multiplied ten-fold and what that's likely to do to the climate and life on earth. It won't be pretty.

7. Industrial agriculture and forestry are one of the leading drivers of climate change (through fossil fuel use, nitrogen emissions and land use change). It's not clever to greatly expand one of the main drivers of climate change in the hope that this will help to cool the planet.

So when you go to discussions about 350 ppm, please be critical. James Hansen is a brilliant atmospheric scientist and he is deeply concerned about the future. However, his background is not in ecology or earth systems science. Yes, of course things will be dire if we stay above 350 ppm, but chances are they will be far more dire if we play around with planetary engineering, tilling vast grassland and soil carbon stores which have remained intact since at least the last ice age. Let's also remember that during prehistoric severe warming episodes, enough biodiversity and ecosystems survived to draw down the atmospheric carbon and eventually re-stabilise the climate and allow life to flourish again. That's why we are here today. If we wipe out more ecosystems and species in pursuit of an impossible target, our chances of wiping out all life forever will greatly increase.

Best regards,

Almuth