Cars and fires are the biggest polluters
Industry is not the big contributor to air pollution in this region. Our biggest polluters are motor vehicles and domestic fires.
Vehicles account for 94% of the nitrogen oxides in the region’s air, 78% of the carbon monoxide and 45% of the carbon dioxide, which is also a major problem for our climate (see below).
In winter, domestic fires are the main problem, particularly in the Wairarapa, Upper Hutt and Wainuiomata which are affected by cold, calm conditions when ‘temperature inversions’ occur.
In winter, very rapid cooling of the earth after nightfall results in a layer of cold air being trapped by warmer air above. Air pollutants from cars and domestic fires also get trapped in the cold layer. With nowhere to go, especially in valleys surrounded by hills, these pollutants can build up to potentially harmful levels.
One of the times you’re most exposed to high levels of air pollution is when you’re driving or a passenger in a motor vehicle.
In fact, the air you’re breathing inside a car can be up to 10 times more polluted than the outside air. It’s worse if you’re stuck in slow-moving traffic because you’re probably breathing in the emissions from the car in front.
The carbon dioxide emitted by motor vehicles not only contributes to health problems. Carbon dioxide is one of the greenhouse gases related to global warming and climate change, which is becoming a serious problem for our environment and our economy.
About 40% of New Zealand’s carbon dioxide emissions come from transport - mostly private cars - and transport is one of the biggest growth areas of our greenhouse gas emissions.