Jokodo
Veteran Member
At the risk of being accused of ONLY pushing the population issue (which I am at the moment, but only to counter the suggestion that it should not be a consideration)........
"Our results also show that reduced population growth could
make a significant contribution to global emissions reductions.
Several analyses have estimated how much emissions would have
to be reduced by 2050 to meet long-term policy goals such as
avoiding warming of more than 2 °C (27) or preventing a doubling
of CO2 concentrations through implementation of a portfolio of
mitigation measures characterized as “stabilization wedges”.
Our estimate that following a lower population path could reduce
emissions 1.4–2.5 GtC/y by 2050 is equivalent to 16–29% of the
emission reductions necessary to achieve these goals or approximately
1–1.5 wedges of emissions reductions (SI Text has details of
this calculation). By the end of the century, the effect of slower
population growth would be even more significant, reducing total
emissions from fossil fuel use by 37–41% across the two scenarios."
Global demographic trends and future carbon emissions
http://www.pnas.org/content/pnas/early/2010/09/30/1004581107.full.pdf
So as far as I can tell, when they say 'following a lower population path' they are referring to the lower path on this predictive diagram:
View attachment 18208
So it suggests that what happens to population over the next 30-80 years is going to make quite a big difference. And the range of population possibilities in the UN estimates include (at the higher path) for population to still be increasing by 2100, so it would seem at least a bit risky to just assume the problem will sort itself out.
Yes. Not to mention that we would not be in this position if our world population had stabilized at 2 billion.
Maybe, maybe not. In 1900, total carbon emmission were about 1/15 what they were in 2015. The population was just over 1/5. The gross global product, however, was about 1/75. This means per capita carbon emission has grown about 3-fold, while carbon emissions per $1000 of wealth generates has fallen about five-fold. If we are allowed to make random hypotheticals (like "if our world population had stabilised"), how about this one: The world population stabilizes, prosperity grows as it does, but the delinking of wealth generated and carbon emissions doesn't happen: We'd be emitting just as much carbon as we are, or possibly more (aren't you overpopulation advocates also constantly claiming that overpopulation is the main reason poor countries stay poor?)
That aside, we have to work with what we have. What we have is a situation where, short of killing 5 billions of healthy individuals, there is no way to get us down to two billion within a reasonable time frame. Even if birth's dropped to 0 today and stayed at 0 indefinitely, it'd take at least 50 and more likely over 60 years before we reached that number: There's in the order of 2 billion people under the age of 15 alive today. So unless you're willing to commit the largest genocide in human history with a victim count two orders of magnitude above the runner-up, this is not a viable corner from which to tackle the problem.
On the other hand, the technology to replace fossil fuels with other energy sources and/or extract carbon from the atmosphere to balance the emissions is available today. Unless genocide is an option for you, worrying about "over"population is thus simply a massive waste of time.