Hi Harry, thanks very much for this positive comment. The challenge is to see the big picture, which means finding an entry point to large scale carbon removal. Most people can’t see that vision, but only because it is so new and different. I am trying to explain these ideas in a simple way. Unfortunately, even the US National Academy of Science has decided to ignore the use of the ocean to remove carbon
, illustrating the difficult politics that block this scientific field.
The balance of risk and reward in this work will be assessed through field trials and computer modelling. We need to prove safety and efficacy, like in drug trials, before scaling up. Our key calculation is that very diffuse spread of iron could remove carbon dioxide for less than a dollar a tonne, orders of magnitude below the cost of other methods.
I am not sure I ever made that precise claim. There may be some emission reduction activities with better economic return on investment, but the overall climate technology problem is achieving the needed scale and speed to stop global warming. Renewables can only displace new emissions, not actually remove CO2. If the goal is CO2 removal, emission reduction cannot be cost effective at all because that is not its purpose. When you look at a country such as Germany
, with power prices triple those of the USA, there is reason to be suspicious of the economic claims of renewable energy. There is such conflicting information about subsidies depending on the economic and political vested interests of advocates that it is very difficult to know what is going on.
Yes, but we are still in a situation where world emissions are expected to rise to 54 GT per year over the next decade, with all the achievements of the Paris Accord only slowing that growth by 10%. Which illustrates that despite its cost effectiveness, emission reduction through renewable energy is marginal to achieving climate stability, which requires negative net emissions. My rough estimate is that we can achieve only 10% of the needed carbon removal through emission reduction, leaving 90% to be achieved through carbon removal methods like iron salt aerosol.
Even accepting these figures, the overall policy for climate restoration should be to identify potential areas of least cost abatement, and thoroughly investigate those areas in order to minimise the expense of adapting to climate change and mitigating its effects. That policy is a very long way away from the attitude of either the left or the right in the current climate wars.