It's probably part of your daily life, even if you don’t notice it. And yet, it kills an estimated seven million people each year. Around the world, countries are waking up and taking steps to tackle air pollution. Governments are cutting back on diesel fuel, getting cars off the street and people onto public transport. But what if all this actually made global warming worse?
At the heart of this paradox are microscopic polluting particles floating around in our atmosphere called aerosols.
They have mirror-like properties, which means they act like shields: they reflect sunlight back into space and thus help keep the planet cool.
On the one hand, aerosols are extremely dangerous, so we should get rid of them. But cleaning up the air could increase global warming and the catastrophic climate effects that go with it. We take a closer look.