It’s been gradually creeping up on me for some weeks now, but the association of colours with environmental matters is reaching epidemic proportions.
Green, meaning something that’s kind to the environment or a commitment to protecting it, has been around for decades. We are unsurprised by figurative terms using the word, even if it isn’t immediately clear what they mean — such as green accounting, in which environmental assets and costs are included in national and corporate accounts, and green budget, which adds such costs into estimates of income and expenditure. Any business providing environmentally acceptable alternatives to traditional products is part of the green sector and contributes green collar jobs to the green economy (as opposed to the black economy, which isn’t about people avoiding paying taxes but the old-fashioned sort that doesn’t consider the environment). The green premium is a payment to cover the extra cost of sustainably grown fruit and vegetables; we may one day be charged a green tax to persuade us to reduce carbon emissions. Green chemistry is the search for alternatives to industrial solvents to help reduce toxic waste, and green gas is another name for biogas, generated from renewable biological sources. A doubly colourful term for biofuels in general is green gold, which has also been appropriated for tea, forests and as a general term for growing plants.
With such a powerful link between good environmental practice and the colour green, it’s not surprising that other colours have been added to the palette for old-style or unpalatable equivalents.
Generally, any fuel created by green methods is green energy and so the traditional sorts are naturally enough brown energy (the alternative to green gas is brown gas, the fossil fuel that comes out of the ground). Quite different is blue energy, also called osmotic power or salinity gradient power, which is electricity that’s generated in river estuaries through the interaction of salt and fresh water. Some people have used yellow energy for the sort that’s gathered directly from the sun using photovoltaic systems. Grey energy or embodied energy is the energy that’s hidden in a product; it might be what was needed to extract it from nature or cultivate, manufacture, package and transport it.
Scientists have begun to study brown carbon, tiny particles of soot given off by burning matter and which both warm the atmosphere and cool the ground. The brown agenda has nothing to do with the policies of the current British prime minister but refers to the environmental problems of big cities in developing countries, which struggle with traditional environmental health issues at the same time as new ones. The green agenda, on the other hand, is a set of proposals for mitigating environmental ills.
Environmentalists refer to green water, which is the stuff that falls from the sky or is taken up by plants from the soil; there’s also blue water, which flows in rivers and streams. Many of us know of grey water, the outflow from household sinks and baths that is increasingly used to irrigate our gardens. Experts in the sewage business, I have learned, talk of black water, otherwise known politely as solid wastes, as opposed to yellow water, which is urine. The last of these has also been called liquid gold, a term which is confusingly and unfortunately also used for water (and sometimes even wine).
Almost certainly, we haven’t seen the last of these invented colour terms. Equally certainly, most of them are destined sooner or later to end up in the recycle bin of language. But while they last, they do add an extra hue to our speech.