Anyone who has walked behind an old bus while it accelerates up a hill will be familiar with the burning of the eyes and stinging on the lungs that occurs when black smoke is inhaled.
Feeling this pain is our natural warning system that this stuff is bad for health, but research is now suggesting that black carbon - the smoke that results from the incomplete combustion of fuel - is also responsible for making glaciers melt faster.
And I have always wondered why they took away the pollution hotline in Auckland City for vehicles that were overly smoky.
But on a world scale, it is also the widespread use of wood fires that releases black carbon, which absorbs the sun's beams, melts the ice and heats the atmosphere.
Last week many people hunkered down against a weather bomb with a wood fire keeping them warm in New Zealand, but we usually have a chimney that removes the poison from our living room so we don't have to see what we are doing to the air.