Wednesday, June 12, 2019

Geoengineering the oceans

Nature has an article (a comment piece) about the dearth of serious research into various suggestions made over the years to use the oceans to counter global warming.   Its seems a lot of ideas are briefly floated but hardly anyone thinks about them very carefully.  

The article does mention a lot of unintended possible consequences of some ideas:
A lack of funding is not the main reason for the research gaps. Although there have been few funding programmes targeted at marine-geoengineering experiments and modelling so far, many basic tests are cheap and can be done in the lab — for instance, assessing whether impurities in mineral powders are toxic to marine life. And a range of negative-emissions technologies, such as enhanced weathering of rocks to increase ocean alkalinity, are already being funded in targeted research programmes, including one in the United Kingdom. Other streams of research, such as modelling, are under way in Germany, and a call for research proposals has been made in Japan. Private money is being invested in some marine approaches, such as a proposed pilot study of the impacts of iron fertilization on fisheries off Chile. However, that project has stalled, largely because of a lack of support from scientists (see Nature 545, 393–394; 2017).

Another problem is that many geoengineering proposals and analyses are found on transient websites, not in peer-reviewed journals. For example, only half of the web links to ideas, plans and documents cited in a detailed 2009 synthesis study of marine-geoengineering approaches4 still worked when we examined them in 2018. By contrast, academic and intergovernmental documents from that era are easy to find.

Again, the reasons for this are unclear, but could include inadequate funding, privacy concerns about disclosing details of the methods, and maintenance of proprietary rights over technologies. Some scientists worry that even starting geoengineering research or reporting results could lead to deployment of inadequately studied approaches5.

Yet it is essential that investigations are solidly researched, openly discussed and made readily available, as demonstrated by the most-studied geoengineering approach, ocean iron fertilization. Much of the work drew from ocean biogeochemistry and has involved lab experiments, pilot studies in the Southern Ocean and modelling across ocean basins. All of this activity showed that the method will not work as anticipated6. Fertilizing 1,000 square kilometres of the upper ocean would increase the growth of phytoplankton but could have alarming side effects. For example, sinking algae could release methane, a greenhouse gas that is many times more potent than CO2
It's clear that there is no simple idea that is an obvious panacea.

1 comment:

GMB said...

If you want to freeze the planet all you need to do is impede the great ocean conveyor. Too easy. Completely genocidal but no difficulty whatsoever. Stefan Bolztmann's law is one of the few laws which works to the 4th power. The upshot is that when we spread the thermal energy out we retain more of it. When we have that heat drop down under colder water thats another way to retain thermal energy. A lot like overturning of air in the troposphere.

The 30 year pulsing of ocean currents is probably to do with the reality that colder water is more viscous. I was the first person to suggest this during the climate debates of 2005-2008. I don't know if the idea has taken off in the last 11 years but I saw another person suggest it one time.

There can never be a heating problem of this planet. We just happen to be a planet with a one-way cooling bias. We may be able to avoid another glacial period simply by seeing to it that no obstructions to the ocean conveyor. During the last extended glacial period, every time we were almost emerging from it, a big chunk of ice would break off around Hudson Bay (close to the poles at that time) and land on top of the gulf stream. This would end our climb out of the glacial period and chuck everything in reverse. You can check it its gold. I found out all this stuff in my climate arguments of that time period.