Pollutionwatch: red sky spells warning when the cause is fire and wood burning

Red sky at dawn and dusk is part of weather lore and apparently a cause for delight or warning among shepherds and sailors. But, as huge areas of forest burn, the crimson colour of skies over the western US is a red alert for our air pollution and climate emergency. Even in New York and Washington DC the sun turned orange. This is because smoke from wood burning strongly absorbs purple and blue light. Longer wavelengths pass through and the sky takes on shades of red.

This curiosity can be useful. In 2005 Swiss scientists noticed that the particle pollution from wood stoves that filled Alpine villages in winter strongly absorbed ultraviolet light, opening a way to routinely measure wood smoke in our air.

Smoke from other solid fuels can strongly absorb purple and blue light too. This may explain the colours in the pea-souper smogs that enveloped London up to the 1960s. In 1855, the Times described the November sky as having the changing colours of a bad bruise. Even in 1947, Arnold Marsh wrote of red and yellow smog-filled skies. It is these tricks of the light that inspired Claude Monet’s iconic paintings of the UK Houses of Parliament.


Please enter your comment!
Please enter your name here

Enter Your Information Below To Receive Free Trading Ideas, Latest News, And Articles.

Please Enter Your Email Address:

Your information is secure and your privacy is protected. By opting in you agree to receive emails from us and our affiliates. Remember that you can opt-out any time, we hate spam too!


Country diary: even in storm-battered fields there are seeds of hope

A borrowed yellow combine lurks behind a hedge, where it was left at 10 o'clock last night. My friend Richard Hudson, the farmer, had...

Nature on UK doorsteps: thousands sign up for daily ‘random acts of wildness’

Try "the snail" during a "wildlife pose" yoga session outdoors. Walk barefoot on the grass in a local park. Go on a rainbow hunt...

Fragile Planet: documenting the impact of the climate crisis – in pictures

On average, the Philippines is hit by 20 typhoons each year. In September 2009, Typhoon Ketsana brought 144km/h (90mph) winds and more than a...

Lib Dems unveil GBP150bn green coronavirus recovery plan

The Liberal Democrats have unveiled proposals to invest GBP150bn in green projects over three years as a way to transform the economy in the...

Climate emission killer: construction begins on world’s biggest liquid air battery

Construction is beginning on the world's largest liquid air battery, which will store renewable electricity and reduce carbon emissions from fossil-fuel power plants. The project...