Global Warming and the Demographic Future

Tim Dyson, London School of Economics and Political Science (LSE)

It was argued in Tours that avoidance and denial have characterized humanity’s response to global warming, and that this would continue. Illustrative calculations showed that even if per capita CO2 emissions in each world region remained constant between 2000 and 2050 there would still be a large rise in total emissions—from population growth. Moreover, the actual rise would be much greater—due to increases in per capita emissions. The present paper shows that recent trends confirm these points. During 2000-19 world fossil fuel consumption rose by 45 percent, and atmospheric CO2 rose from 370 to 411 ppm. The much-vaunted Paris Agreement makes no direct mention of the negative-emission technologies that are required to achieve its aims. The paper explores the future through a demographic lens. It illustrates that seemingly distant dates are actually fairly close. It documents the—largely unrecognized—fact that the growth rates of atmospheric CO2 and world temperature are both accelerating. A doubling of atmospheric CO2 seems set to occur before 2100. Relatedly, the Paris Agreement’s 2°C aim is fanciful. Further, the paper argues that—partly for climate-related reasons—world population growth after 2050 is likely to be appreciably less than is currently projected.

Keywords: Population projections, forecasts, and estimations, Population size and growth/decline

See paper.

  Presented in Session 173. Population Shifts and Environmental Change: Past Trends, Current Conditions and Future Scenarios