Sensitivity training

This article was originally published online at Corporate Knights Magazine and will appear in the publication’s Fall 2016 hard-copy magazine. It was also previously republished, in part, at Skeptical Science.

Climate scientists are certain that human-caused emissions have increased carbon dioxide in the atmosphere by 44 per cent since the Industrial Revolution. Very few of them dispute that this has already caused average global temperatures to rise roughly 1 degree. Accompanying the warming is disruption to weather patterns, rising sea levels and increased ocean acidity. There is no doubt that further emissions will only make matters worse, possibly much worse. In a nutshell, that is the settled science on human-caused climate change.

What scientists cannot yet pin down is exactly how much warming we will get in the future. They do not know with precision how much a given quantity of emissions will lead to increased concentrations of greenhouse gases in the atmosphere. For climate impact it is the concentrations that matter, not the emissions. Up until now, 29 per cent of human emissions of carbon dioxide has been taken up by the oceans, 28 per cent has been absorbed by plant growth on land, and the remaining 43 per cent has accumulated in the atmosphere. Humans have increased carbon dioxide concentrations in the atmosphere from a pre-industrial level of 280 parts per million to over 400 today, a level not seen for millions of years.  Continue reading

Carbon sequestration in basalts

I have just had a piece published in the Bulletin of the Atomic Scientists: ‘We’d have to finish one new facility every working day for the next 70 years’—Why carbon capture is no panacea . I’m not allowed to repost the whole article here, but it is open access on the Bulletin website.

I looked again at the outsized role that carbon capture and storage (CCS) along with Bioenergy Carbon Capture and Storage (BECCS) play in most of the IPCC 2 degree models. I have argued previously that the gigantic quantities of CO2 that need to be sequestered in geological reservoirs, according to these models, face huge obstacles in terms of scalability, financing, technical hurdles and public acceptance.

A recent paper in Science reported on a breakthrough experiment in Iceland in which CO2 (from a volcanic source) dissolved in water was injected into basalts at depths of 400-1000 metres. Using isotopic and chemical tracers, the researchers estimate that the CO2 had been mineralized into benign and stable carbonate minerals in the space of just two years. This was faster than suspected and, if this process turns out to be scalable, then sequestration in basalts would provide a solution to the need to monitor conventional sedimentary rock disposal sites for leakage over the long term. Continue reading