Planet Earth's nine lives: Our planet's limits
Aerosol loading – smoke, dust and soot
An aerosol is a spray can that you use, right? Yes but it's also smoke and dust that affects people's health and pollutes the air. Not nice, huh? Humans make a big mess wherever they go, churning out masses of smoke or dust aerosols from
This smoke and dust is made up of very tiny particles, which are so light that they get wafted up into the atmosphere where they stay for weeks or months. They are called aerosols and they affect the climate and people's health. Soot particles – a major part of these aerosols – cause the climate to warm up because they are black and absorb heat from the sun. Sulphate particles (from burning coal mostly, and also from large volcanoes occasionally erupting) can cause local cooling. A brown haze of smoke sits permanently over India and is called the Asian brown cloud. It seems that this not only causes warming but also partly blocks the life-giving monsoon rains which Indian farmers depend on for growing food.
Nobody knows what limits should be set for the dusty haze of smoke, soot and sulphate particles humans are making. It looks like it should be a lot less than now.