It’s annoying that as soon as the sun comes out, so do the neighbours’ bonfires, and barbecues, to spoil the washing and make the house smell.

However, it’s far worse in Singapore, and nearby Malaysia, as in the middle of June they were suffering from the worst air pollution since 1997, leading to radio advice to stay indoors.

Satellites showed that the culprit was 113 forest fires in Indonesia, to the south and west, where palm oil plantations were being extended by clearing and burning the forest.

In 1997, the whole area was almost brought to a standstill as 20 million acres of forest burned for up to a year, and in Borneo some of the deep peat fires are still alight. The record air pollution caused a serious health hazard – the equivalent of smoking 60 cigarettes a day.

It’s interesting that the amount of CO2 added to the atmosphere in 1998 was a record for one year, at 2.93 parts per million, and it’s reckoned that the carbon from those fires was about one fifth of the annual total from the burning of fossil fuels.

Since then, even more burning of coal, oil and gas probably explains why 2012 had the second-highest increase of CO2 in the atmosphere, at 2.65ppm, but it was certainly helped by the greater number of large wild fires world-wide, including Australia, Russia and the USA.

However, it’s not just the CO2 that’s a problem as the smoke, haze and general poor visibility has another important influence that is sometimes overlooked – it stops some of the heating from the sun. Older readers will remember the fogs of the 1950s and early-1960s that made it difficult to get about in the Bradford district – it was quite easy to get lost. This was all due to burning coal and household waste on open fires, so Clean Air Acts were passed throughout Europe and there were two results. The first was cleaner air and less coughing, but it was the second that was really important – the world temperature started to increase as the sun’s rays could now heat the ground and the oceans, and weren’t reflected back out before raising the temperature.

Fifty years after we cleaned up our air, Asia is about to do the same, as the recent industrialisation of the whole area, from India through Vietnam to China, has produced an enormous brown haze, and poor air quality that threatened the Beijing Olympics.

Once the Asian air is cleaned up, there will be nothing to stop the sun heating the atmosphere even more strongly, so it’s just another reason why we must stop using fossil fuels.