Sunday 25 October 2015

Solar Radiation Management: Effects on Earth


This blog aims to assess a process of geoengineering, specifically solar radiation management (SRM).  SRM is the artificial use of aerosols, to increase Sun reflectivity away from the Earth, and decrease global temperatures (Keith et al 2010).  The globe is expected to increase in temperatures due to increasing carbon dioxide levels. Hence, with the use of SRM there is more reflection of the sun away from the stratosphere and less heat reaches the Earth’s surface (similar to a volcano’s eruption) (Figure 1).


Figure 1: Solar Radiation Management methods to reduce the Sun reflection
Source: The Ecologist



The SRM aims to reduce temperature and hence reduce glacial ice melt and sea level rises, that may occur with increasing temperatures (Burns 2011). Applegate and Keller (2015) suggest that SRM process, will help reduce these impacts through assessing  the Greenland Ice Sheet.  If SRM is effective, this may help the tundra biome to be sustained and reduce environmental impacts.  However, it is expected that this process will take place around 2025, according to the model and will need approximately a further decade for the SRM processes to be effective.  Hence, this delay in the use of SRM procedures, will likely lead to further dramatic impacts.  Applegate and Keller suggest that once the glacial ice melts, it is hard to restore it back to its initial conditions and thus the SRM impacts may not be as effective as anticipated.

As the artificial aerosols tend to be composed of sulphur it is likely that rain will be acidic. This may be problematic as it may contaminate freshwater ecosystems such as lakes and rivers and lead to a depletion of species such as fish as seen in Scandinavia (Pyatt 1987).  A degradation of forests may occur through acid rain, such as in Germany due to the industrial revolution (Walgate 1983).

Thoughts:

SRM may be more beneficial and effective, if the process takes place as soon as possible.  However, there are high levels of uncertainty as it is a new process.  Hence, it is very likely that acid rain may occur with SRM, creating further damage to Earth rather than repair. 

Is it worth the risk undertaking SRM processes? Follow me next week to assess people’s thoughts on the matter; but for now, feel free to input your own thoughts.





8 comments:

  1. As someone who feels very passionately about freshwater ecosystems, I'm not on board with pumping more sulphur into the atmosphere! It is incredibly counter productive to sacrifice one part of the biosphere for the sake of protecting others. I think there could be huge potential in SRM but we should look for other mechanisms. I look forward to your next post on this :D

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  2. hey! thanks for your comment! i totally agree with you! SRM (specifically adding aerosols to the atmosphere) is un-appealing for me! I feel that it won't actually resolve the problem! I will be talking next week more about people's feelings on the matter!

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  3. I agree with Ben - the risks to freshwater ecosystems seem too large to experiment with putting sulphur in the atmosphere! Great article though - I know very little about solar radiation management and geoengineering so I can't wait to read more of your blog!

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    1. Thanks Celia! I feel that the risks will not be only to freshwater ecosystems, I believe that people may have respiratory problems and also that this may not actually solve the climate change impacts!

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  4. Sounds a very interesting story of new technology, Maria! Like Ben and Celia pointed out, I think the current SRM system seems to face a lot of troubles. I wonder if any scientists come up with an alternative method. I do not know much about geoengineering, but it is certainly something that has recently been receiving a great attention. Looking forward to your next blog!

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    1. Thanks for your comment Satomi! There are many SRM methods, however the most discussed, easiest and cheapest to imply, is the use of aerosols in the atmosphere. And yes it has been receiving great attention, one of the reasons why I chose this topic for my blog!

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  5. Have you considered yet other forms of SRM, such as building mirrors in space, or brightening clouds using sea-water droplets?

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    1. not in this case, although i feel that I did not make this clear when writing and it seems as if I am referring to all SRM processes. However, i do aim to consider the other forms of SRM in future blogs.

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