Oh, no, yet another greenhouse gas!

Sulphuryl fluoride, also known as sulfuryl fluoride has been identified as another greenhouse gas by scientists at the Massachusetts Institute of Technology and at the Scripps Institution of Oceanography. The chemical is used in gaseous form for fumigation.

Fumigation is an important process. A fumigant gas is used to kill insects and other pests in grain stores. If fumigants were not used much of the grain stored would be eaten away by insects. If you have ever seen vast areas of growing land covered in plastic sheets you might not know that the reason for the plastic sheets is to control water loss from the soil by evaporation. You might not also know that under the plastic fumigant gases are often introduce to protect the crops.

Other food produce is very attractive to insects – flour, cheese, chocolate and finished food are all targets for insects and are usually fumigated to preserve them from insect attack.

Fumigation also uses gases to preserve buildings, old furniture and many other items that are worthy of preservation. Once the thing needed fumigation is sealed in an air tight enclosure, the gas is released and held in the enclosure long enough to kill off the pests. Then the enclosure is opened and the gas released into the air. Once the gas has all gone, the space is safe to enter and the food or building free from pest, and in the case of insects, free from their eggs.

For many years until 2005 methyl bromide was one of the most widely used fumigant gases. It was identified as a substance that depletes the ozone layer, and as such was banned from use in 2005 by the Montreal Protocol.

Since then, sulfuryl fluoride has often been used to replace the methyl bromide, but now we have learnt that this was a case of jumping out of the frying pan and into the fire. Although there are very small amounts of this gas in the atmosphere (less than 1.5 parts per trillion)  it has been discovered that it is 4,800 times more potent as a greenhouse gas than carbon dioxide and that it stays in the atmosphere for about 36 years until it sinks into the ocean.

The present tiny atmospheric content of this gas means that there is no cause for immediate alarm, but it is as well to prevent its use now, so as to avoid its atmospheric concentrations rising in the future. Its concentration is rising at around 5% per annum, but by increased us, that rate could easily gallop away. That would mean that with increased use and the compound growth (because the gas lasts for 36 years) that we could easily see it significantly adding to the rate of climate change is nothing is done to prevent its use.

Now that we know about the potential danger of sulfuryl fluoride, we have time to ensure that we seek out other safer and non climate changing alternatives, before business make large investments in sulfuryl fluoride production factories. They cannot now say that they have not been warned.

Although our food is very fully labeled, the labeling process does not indicate whether fumigants have been used and if so what fumigants. As I understand it, most organic standards prohibit the use of fumigants, so part from whatever other advantages of eating organic may bring, it is good to know that there is no climate change danger associated with genuinely organically produced food.

 

3 Responses

  1. […] FarmPolicy.com added an interesting post on Oh, no, yet another greenhouse gas!Here’s a small excerpt…because the gas lasts for 36 years) that we could easily see it significantly adding to the rate of climate change is nothing is done to… […]

  2. Wow thanks for this post! I find it fascinating how greenhouse gas emissions are so complex and vast. I think that more information needs to be out there for the public to better understand what green house gases are, and how it relates to their lives. Does anyone know of any good sites for this information?

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