Joe Chamie calls targeting unintended fertility a "delay tactic" that hinders the immediate pursuit of reducing resource consumption. Again, we want to reiterate that we don't view this as an either-or proposition. Instead, to avoid catastrophic climate change, we believe that the international community should pursue the methods that Fred Meyerson describes below to reverse population growth and ways in which to reduce resource consumption.
The time we have available to achieve both of these goals is key. As stated previously, the United Nations currently projects [PDF] that world population will reach about 9 billion by 2050. Meanwhile, David Rutledge at the California Institute of Technology recently looked at projections for the depletion of conventional oil, gas, and coal reserves based on the application of M. King Hubbert's technique for determining peak oil and estimated that, by 2076, 90 percent of these reserves will be gone.
This is a much shorter timescale than previously believed--especially for coal, where mainstream predictions had indicated up to a 250-year supply. Rutledge's projections for coal production take into account new assessments of the recoverability of coal reserves, which may not be as accessible as once thought, and it's possible that earlier coal forecasts were based on current usage rates and didn't factor in acceleration from population growth and increased affluence. Several countries have already severely downgraded their reserves: In 2004, Germany, the largest coal producer in the European Union, reduced its estimated black coal reserves by 99 percent and its brown coal reserves by 80 percent.
Aside from the devastating climate effects of burning all our fossil fuel, if demographers and Rutledge are correct, in less than 70 years, humankind will number 9 billion and energy will be scarce and expensive. Assuming that current growth in renewables and nuclear energy could provide 60 percent of the current world energy needs by 2075, Rutledge lays out the stark challenge facing humankind: Cut energy demand to 40 percent less than it is today and reduce global population to around 5 billion. We think this population target is still too high, given that Routledge doesn't take into account attrition in agriculture and land availability by that time.
Because nearly one-half of the world's population is under the age of 25, placing them in the midst or still ahead of their childbearing years, reversing population growth cannot be achieved before 2050. Only a catastrophic die-off could make it happen sooner. The alternative is Fred's top-tier prioritization of voluntary family planning, plus education and media outreach now. Further delay means that we must contend with nearly a billion extra humans to feed and clothe every decade.
It's all very well and good to say, as Joe does, that in Africa, "per-capita emissions are already so low that lower birthrates would not make a noticeable dent in total global emissions." But this implies tolerating an appalling status quo: Who among us doesn't passionately want to see the poorest people of the world escape their unacceptable poverty? It's not difficult to understand that one less person born into poverty is one less person who needs to be helped out of poverty--a development process that cannot occur without increased energy consumption and (in the medium term) more carbon-dioxide emissions per person.
The data we gave in our first post showed that in 2003, Africa had a per-capita ecological footprint of 1.1 global hectares (gha) against an available biocapacity of 1.3 gha per person. In other words, more than a 17.6-percent increase in Africa's population will make it impossible for even underdeveloped states to sustain their current populations due to space, energy, and (especially) water constraints. As Africa doesn't have the same buffer of wealth as the developed countries possessed when they crossed the line of unsustainability, that process will have a much harsher impact on Africans. One of us (John Guillebaud) was born and brought up in Burundi and Rwanda, and from recent visits, he knows firsthand how many sub-Saharan African countries are already on the verge of demographic entrapment. Once the environmental carrying capacity is grossly exceeded, the only likely outcomes are starvation, disease, interethnic violence and genocide, migration (and to where?), and/or dependence on aid from the international community.