James Hansen calls for geoengineering

[UndercoverElephant]

https://time.com/6330957/james-hansen-c ... reddit.com

We Need Geoengineering to Stop Out of Control Warming, Warns Climate Scientist James Hansen

Although Hansen was the person who wrongly told everybody we are heading for Venus-style runaway warming....

[clv101]

Hansen's Venus thing was an academic curiosity, not something he said was going to happen:

He wrote:

Earth can "achieve" Venus-like conditions, in the sense of ~90 bar surface pressure, only after first getting rid of its ocean via escape of hydrogen to space. This is conceivable if the atmosphere warms enough that the troposphere expands into the present stratosphere, thus eliminating the tropopause (see Fig. 7 in our paper4 in press), causing water vapor to be transported more rapidly to the upper atmosphere, where it can be dissociated and the hydrogen can then escape to space. Thus extreme warming of the lower atmosphere with elimination of the cold-trap tropopause seems to be the essential physical process required for transition from Earth-like to Venus-like conditions. If Earth's lower atmosphere did warm enough to accelerate escape of hydrogen it would still take at least hundreds of millions of years for the ocean to be lost to space. Additional time would be needed for massive amounts of CO2 to accumulate in the atmosphere from volcanoes associated with plate tectonics and convection in Earth's mantle. So Venus-like conditions in the sense of 90 bar surface pressure and surface temperature of several hundred degrees are only plausible on billion-year time scales.

This is the same process Peter Ward describes in his 'life and death of planet earth' book.

[UndercoverElephant]

OK, I have been a bit on hard on him then.

[clv101]

But he is absolutely right about geo-engineering. We tried to mitigate emissions in order to avoid dangerous climate change and utterly failed. Likely new record this year. We tried carbon capture and storage, no bueno. Next came direct air capture and BECCS, even worse... Reaching lower down into the tool box geo-engineering is next up! I have little doubt there will be a serious attempt, if, industrial civilization maintains current capacity to do stuff for another couple decades.