Are the emissions and concentrations trajectories plausible?
68. Many factors affect greenhouse gas emissions and atmospheric concentrations. Thus, even if the underlying assumptions about economic growth were correct in the IPCC SRES, a further test of reasonableness would be to compare projected and past emissions and atmospheric concentrations. In her evidence to us, Ms Rosemary Righter, Associate Editor of The Times, drew attention to the divergence between recent historical trends in CO2 per capita emissions and CO2 and CH4 concentrations, and the high emission scenarios[65]. A similar point was made by Mr Martin Ågerup of the International Policy Network in his evidence[66]. Table 6 shows historical data on emissions. The table shows that, while emissions of CO2 are increasing, the rate of global increase has fallen steadily since 1960. Similarly, per capita emissions are falling, not rising, and “carbon intensity” carbon emissions divided by GDP is also falling at a fairly constant rate. These changes in the past 30 years or so can be com
