Geo-engineering

Last-Ditch or Routine?

Given that we have beeen geo-engineering the planet since we began clearing forests and plowing the land, it should come as no surprise that we can make planetary scale changes to our world. If we add to that the major changes we have made to the atmosphere by adding greenhouse gases, we can learn from our experiments already carried out what to be careful of implementing without careful consideration. The knowns:
*Forest practices to increase carbon absorption
*Biochar addition to the soils is an ancient technique for sequestering carbon
But both of these teccniques require very large land areas to make a difference.

And then there are the untested approaches tht just delay the inevitable uless major reductions to greenhouse gases in the atmosphere are carried out at the same time.
*Albedo or reflectivity changes like space mirrors, aerosols in the high atmosphere, cloud seeding, relective plants, and painting roads and houses white.
*Changing the ocean productivity using iron fertilization or carbonate additions.
*Carbon sequestration using gigantic air filters or articifial trees.

Some of the Potential Geo-Engineering Approaches

Some of the Potential Geo-Engineering Approaches

 Re-Freezing the Arctic?

Image courtesy of Dana Kyson

Image courtesy of Dana Kyson

A paper by Desch, S. J., Smith, N., Groppi, C., Vargas, P., Jackson, R., Kalyaan, A., Nguyen, P., Probst, L., Rubin, M. E., Singleton, H., Spacek, A., Truitt, A., Zaw, P. P. and Hartnett, H. E. (2017), Arctic ice management. Earth's Future, 5: 107–127 has suggested that the best way to rapidly manage the global climate is to re-freeze the Arctic and recover the sea ice so that the reflectivity of the planet is raised back up enough to slow down the temperature increase. The late-summer Arctic will most likely be ice-free by the 2030s. As the sea ice disappears, the sunlight is absorbed by open ocean rather than reflected back by ice. The idea is to use wind power during the Arctic winter to pump water to the surface, where it will freeze. They calculated about 10 million pumps covering about 10% of the Arctic might return about 1 m of ice to the Arctic Ocean in a single year.

Now the scientists are going to do a trial run in Switzerland to see if the idea is feasible by adding snow to a glacier to try to stop its retreat. If this is successful even in the hottest months of the year then it is a good indicator that the idea might work in the Arctic.

Carbon Capture and Sequestration

Carbon capture from the open atmosphere is very difficult primarily because the carbon is in the form of CO2 which is very much a trace gas at a mere 400parts per million. To capture the CO2, giant fans are erectied that blow th air across a sponge-like material that uses amine-based chemical sorbents bonded to porous honeycomb ceramics that act as carbon sponges. Low pressure stean is used to strip the captured carbon dioxide and collect it. The end prioduct is nearly 98% CO2. No other effluents are involved and onlysteam and electricity are consumed. If the electricity is carbon free, then the yield on CO2 is excellent.

from www.fastcoexist.com

from www.fastcoexist.com