RTSea Blog ran two posts on the subject in 2009, and the concerns over the side effects of geoengineering expressed then by scientists still exist today.
- Geoengineering: big ideas to change the planet
- Geoengineering: changing the earth's climate for better or worse?
Geoengineering is the process where global steps are taken to counter the effects of global warming, as opposed to addressing the source of the problem - like treating a disease symptomatically. It has been said that geoengineering is not the "silver bullet" solution but may have to be considered along with other measures aimed at the root of our global warming problem, that of excessive CO2 emissions (which, ironically, is a geoengineering process unto itself).
Many of the proposals seem petty grandiose or something right out of a science fiction novel but, in most cases, the technology is there; it will need international cooperation to ramp it up to a global scale. Here are a few of the latest proposed techniques listed by USA Today:
•Ocean fertilization. Dumping iron filings into the ocean to spur phytoplankton blooms is the saltwater version of forestation. The increased mass of the plankton's cells would swell with carbon pulled from the air. On the downside, it may kill fish, belch out other greenhouse gases such as methane, and hasn't worked very well in small trials. [Also mentioned in my prior posts.]
•Forestation. Intense planting of trees and reclaiming deserts with hardier plants is one of the ideas endorsed at the recent Cancun, Mexico, climate meeting, where representatives of 192 nations made some progress on an international climate agreement. More fantastic versions, endorsed by Princeton physicist Freeman Dyson, would rely on genetic engineering to produce trees that act as natural carbon scrubbers, their trunks swollen with carbon pulled from the air.
•Cloud engineering. Painting rooftops white, genetically engineering crops to have shinier surfaces, and floating blocks of white Styrofoam in the oceans are all proposals to mimic the effects of clouds, whose white surfaces reflect sunlight. Pumping sea salt into the sky from thousands of "spray ships" could increase clouds themselves. Cost-effectiveness aside, such cloud-seeding might end up dumping rain on the ocean or already soggy regions, instead of where it's needed.
•Pinatubo a-go-go. As mentioned above, sulfur aerosols could be fired into the sky by cannons, released by balloons or dropped from planes. [Also mentioned in my prior posts]
•Space mirrors. Hundreds of thousands of thin reflective yard-long disks fired into a gravitational balance point between the sun and Earth could dim sunlight. Cost aside, rocket failures or collisions might lead to a tremendous orbital debris cloud circling the Earth. And a recent Geophysical Research Letters space tourism report suggests the rocket fuel burned to launch the needed number of shades would dump enough black soot — which absorbs sunlight and heats the atmosphere — to increase average global temperatures about 1.4 degrees.
Just as CO2 emissions and rising overall world temperatures disrupt currents, winds and other weather patterns, thereby producing more storms, droughts, and even cold spells in some parts of the world; counteracting global warming through geoengineering can do the same. In fact, it can have political or national security implications: what if one nation has the means to manipulate geoengineering so that it could produce droughts or alter storm tracks in another part of the world? Now there's something that seems right out of a DC/Marvel comic book.
While "most of the technologies are not yet proven and are at the theoretical or research phase," according to an August Congressional Research Service report, geoengineering is slowly gaining acceptance as a viable approach worth pursuing. "I think it is settled that some climate engineering research will go forward," says Science magazine reporter Eli Kintisch. "We haven't seen it enter the national debate yet. Hard to know what will happen when it does. That may be the biggest question."
Read the article in USA Today.