Inspired this week by Sir David Attenborough’s “rewrite our story” speech at the start of the climate conference (COP26), I see opportunity for young innovators (like my kids) during their lifetimes, and wonder again if I should shift my attention from saving whales and studying marine bioacoustics to working more directly on climate change as an “issue of our time.” The common thread for me is population — of Southern Resident killer whales (SRKWs) on one hand, and of human beings on the other.
In my lifetime, I expect to see either the extinction of SRKWs, or possibly the beginning of a recovery. When I chose to work on SRKWs instead of hydrothermal vents and the origins of life back in 2003 I imagined we’d soon see something like the 2.9% growth rate by 2020 that NOAA set as a target, but that definitely didn’t happen and is looking unlikely for decades due to the SRKW population structure and failure to recover salmon along the west coast of the U.S. and Canada.
For humans, there’s a small chance I may get to witness humanity “getting over the hump” — just starting to experience a global population decline and stabilization — but it’s much more likely that only the next generation or two may bear witness to that. Interestingly, researchers right here in Seattle at the University of Washington (UW) have offered new forecasts recently (see 2020 Lancet paper) which build upon the 2019 UN and other recent forecasts.
Based on this breakdown of population history and forecasts by continent/region (below, from the Pew Research Center), it seems my chances of seeing human population peak and start to decline will hinge primarily on how population growth in Africa is handled, and secondarily in Asia. That continent may be a prime landscape for innovations that improve the living and education standards, especially for women (specifically the “educational attainment and contraceptive met need” components of the UW forecast model), and that — ideally, simultaneously, secondarily — turn the knob on climate change (e.g. reducing deforestation,
Another figure in the Lancet paper shows the year in which countries will have their net reproduction rate fall below the replacement level. If the goal is slow Africa’s contribution to global population growth as soon as possible, this figure may suggest where in Africa innovation could be of greatest benefit. Zimbabwe, Somalia, South Sudan, the Central African Republic, and Chad are highest priorities. Secondary foci could be Madagascar, the Democratic Republic of the Congo, Niger, and Algeria.
Of course, the population density in each of those countries in Africa, and others around the world, is also important in generating significant change. The final figure of the Lancet paper that wowed me is the ~1 billion person range in Nigeria’s population trajectories: