At the meeting the body's members also backed a plan that will cap net emissions of carbon dioxide from international aviation from 2020.

The government has committed itself to zero net emissions.

I did not refer to the industry's claim that if you subtract the carbon trees absorb while growing net emissions are very low.

To qualify, houses must have 'zero net emissions of carbon dioxide from all energy use in the home' - a standard that few properties in the country satisfy.

The modifications made would increase net emissions per year.