Stop burning fossil fuels now: there is no CO2 'technofix', scientists warn

German researchers have demonstrated once again that the best way to limit climate change is to stop burning fossil fuels now.

In a “thought experiment” they tried another option: the future dramatic removal of huge volumes of carbon dioxide from the atmosphere. This would, they concluded, return the atmosphere to the greenhouse gas concentrations that existed for most of human history – but it wouldn’t save the oceans.

That is, the oceans would stay warmer, and more acidic, for thousands of years, and the consequences for marine life could be catastrophic.

The research, published in Nature Climate Change today delivers yet another demonstration that there is so far no feasible “technofix” that would allow humans to go on mining and drilling for coal, oil and gas (known as the “business as usual” scenario), and then geoengineer a solution when climate change becomes calamitous.

They calculated that it might plausibly be possible to remove carbon dioxide from the atmosphere at the rate of 90 billion tons a year. This is twice what is spilled into the air from factory chimneys and motor exhausts right now.

“Interestingly, it turns out that after ‘business as usual’ until 2150, even taking such enormous amounts of CO2 from the atmosphere wouldn’t help the deep ocean that much - after the acidified water has been transported by large-scale ocean circulation to great depths, it is out of reach for many centuries, no matter how much CO2 is removed from the atmosphere,” said a co-author, Ken Caldeira, who is normally based at the Carnegie Institution in the US.