The imbalance is what matters and it amounts to about 3.5 billion tonnes of CO2, about half of man's production. This annual unbalanced contribution by man is almost certainly the cause of the tremendous growth of the CO2 concentration in the atmosphere, from about 285ppmv in 1900 to 360 or more today, increasing at about 15ppmv or 4.5 per cent per year. This, arguably, is resulting in the global warming being recorded.
I fully support the comments in the other letters from David Adams and Richard Woodhurst. We must do ever more to conserve energy ourselves.
Our biggest problem, however, is convincing the USA that they are criminal in their waste of energy resources and in their blatant disregard of the environment in continuing to emit CO2 on such an irresponsible scale.
E J M HEPPER