The building sector is the sector in which greenhouse gas emissions could be greatly reduced: -29% by 2020. This would not cost much as the technical solutions already exist. Good double glazing reduces heat loss by 15 to 20%. Lighting that goes off when the room is empty, energy-saving bulbs and a better use of natural light could reduce energy consumption linked to domestic lighting by 75%. Every year, this emits 1.9 gigatons of CO2.
Extremely simple steps can bring about surprisingly significant changes. On a planetary scale, whitening all roofs would reduce CO2 emissions by 44 billion tons. This, as the roofs would reflect more energy into space and therefore reduce the number of warming infrared rays. Alternately, covering them with vegetation provides better insulation.
The other major urban issue regards journeys. We can reduce pollution by developing motors that consume less and by using alternative fuels and electrical energy. But for better mobility, the very conception of towns must be examined. Eco-quarters, Vauban in Freiburg and the BedZED development in London have shown us how to live without cars. 50% of all car journeys are less than 5 km long, especially in Europe. In most cases, people could walk, ride a bicycle or use public transport.
Today, eco-quarters as they are called, are still isolated initiatives on a small scale because cities are developing slowly. Urban policies need time to be applied. Houses have quite a long life span and building professionals are not always trained to use new techniques. But cost is not usually a determining factor, as governments often offer subsidies. The savings often rapidly make up for the extra cost..