Ed’s note: Solar dimming – the answer for global warming?

In January a group of scientists from across the globe published an open letter advising against dimming the Sun as a measure to lessening the impact of global warming and calling for an ‘International non-use agreement on solar engineering’.

This idea of dimming the Sun’s rays has been gathering ground in some quarters and would involve injecting particles such as sulphur into the upper atmosphere, where their effect would be similar to that of the sulphur dioxide that is sprayed into the air in volcanic eruptions.

The 1991 eruption of Mount Pinatubo in the Philippines, for example, is said to have lowered the Earth’s average temperature by about 0.4°C for over a year.