RECENTLY a correspondent wrote a letter voicing concerns over the diminishing albedo effect if the Arctic ice sheet were to melt.

The albedo effect refers to bright white ice reflecting the Sun’s rays back into space and thereby keeping the planet cooler.

During our recent frozen winters there was extensive snow and ice coverage all over the Northern hemisphere, providing a huge albedo effect comparable to the last ice age.

The insolation or solar radiation that Earth receives is a very important factor in climate change.

For the last 6,000 years this insolation has been steadily decreasing.

The measured solar levels are now getting so low as to be sufficient to precipitate another ice age.

Indeed before the global warming zeitgeist became popular, scientists were voicing concerns about the imminent ice age.

However carbon dioxide levels have risen recently and this may be stalling the expected ice age.

This is because carbon dioxide levels need to be below 280ppm to facilitate the ice age and they are presently at around 360ppm.

When I met Sir David King at the inauguration of the 21st Century School he mused that perhaps our carbon emissions were stalling the onset of this ice age.

However we need to consider the dire possibility that these carbon emissions will not prevent this overdue ice age. To that end it is a good policy to provide good levels of home insulation.

During the last ice age, the Midlands and the north of England were buried under a mile of ice.

SUSAN THOMAS
Magdalen Road
Oxford