When it comes to climate change, contaminated land is the forgotten risk.
Climate change leaves us worrying about quite a lot of things: tropical diseases, extreme weather events, extinctions... But we don’t tend to worry about pollution outbreaks. In DEFRA’s climate change risk assessment, it doesn’t even get a mention.
But is that because we’ve forgotten the risks, or because we don’t know?
Lots of land is “contaminated land”. This doesn’t mean it glows yellow in the dark or is a breeding site for mutant flesh-eating bacteria. Most land is contaminated by waste from agriculture, industry, energy or medicine, and that can be anything from fertilisers that cause algal overgrowths to pharmaceuticals that make male fish feminine[1]. Humans like to concentrate chemicals to put them to use doing specific jobs. This is great when they’re where they’re supposed to be, but leftover chemicals or waste products are still relatively concentrated and can be poisonous or harmful.
Contaminants can also come from the land itself: like arsenic, which is rife in various rocks. Or radon, a radioactive gas found in granite, and especially Cornwall.
There are three main ways of dealing with chemicals in the environment:
1. Spread them out – diluting them more and more until they’re no longer at harmful concentrations
2. Concentrate them – and lock them up in a box or a landfill somewhere they can’t do any harm
Or 3. Change them. Chemical reactions can change the nature of some chemicals, such as pharmaceuticals, making potentially harmful things into harmless things.
These processes are called remediation.
Climate change leaves us worrying about quite a lot of things: tropical diseases, extreme weather events, extinctions... But we don’t tend to worry about pollution outbreaks. In DEFRA’s climate change risk assessment, it doesn’t even get a mention.
But is that because we’ve forgotten the risks, or because we don’t know?
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| Extreme weather may affect land safety, access and use. Image © Rowena Fletcher-Wood |
Lots of land is “contaminated land”. This doesn’t mean it glows yellow in the dark or is a breeding site for mutant flesh-eating bacteria. Most land is contaminated by waste from agriculture, industry, energy or medicine, and that can be anything from fertilisers that cause algal overgrowths to pharmaceuticals that make male fish feminine[1]. Humans like to concentrate chemicals to put them to use doing specific jobs. This is great when they’re where they’re supposed to be, but leftover chemicals or waste products are still relatively concentrated and can be poisonous or harmful.
Contaminants can also come from the land itself: like arsenic, which is rife in various rocks. Or radon, a radioactive gas found in granite, and especially Cornwall.
There are three main ways of dealing with chemicals in the environment:
1. Spread them out – diluting them more and more until they’re no longer at harmful concentrations
2. Concentrate them – and lock them up in a box or a landfill somewhere they can’t do any harm
Or 3. Change them. Chemical reactions can change the nature of some chemicals, such as pharmaceuticals, making potentially harmful things into harmless things.
These processes are called remediation.
