Change is the one constant

Fill in the blanks:

It is customary in the popular media and in many journal articles to cite a projected _________ figure as if it were a given, a figure so certain that it could virtually be used for long-range planning purposes. But we must carefully examine the assumptions behind such projections. And forecasts that ________ is going to level off or decline this century have been based on the assumption that the developing world will necessarily follow the path of the industrialized world. That is far from a sure bet.

That comes from an essay at Yale’s e360.

Given that you’re reading a blog concerned with climate change, you are excused if you slotted in “carbon emissions” or something similar. The correct answer is “population,” but the author’s argument is equally applicable to either issue. Carl Haub, senior demographer at the Population Reference Bureau, is simply pointing out that the experts on such matters are often wrong when they take current trendlines and extrapolate them decades into the future. And he writes that some of the assumptions built into the oft-cited UN estimates of a global population leveling off around 9.5 billion four decades from now are highly questionable.

The UN’s middle-of-the-road assumption for sub-Saharan Africa — that fertility rates will drop to 3.0 and population reach 2 billion by 2050 — seem unrealistically low to me. More likely is the UN’s high-end projection that sub-Saharan Africa’s population will climb to 2.2 billion by 2050 and then continue to 4.8 billion by 2100. The dire consequences of such an increase are difficult to ponder. If sub-Saharan Africa is having trouble feeding and providing water to 880 million people today, what will the region be like in 90 years if the population increases five-fold — particularly if, as projected, temperatures rise by 2 to 3 degrees C, worsening droughts?

Similarly, it is perhaps timely to point out that “business as usual” carbon emissions rates are almost certainly not going to continue for much longer. The cost of solar power and other clean renewables will almost certainly continue to fall (though not at current rates of more than 30% a year in the case of PV). But demand for power is continuing to rise (at less predictable rates thanks to economic instability). I just don’t see how we can predict with any degree of confidence how many atoms of carbon we’ll be spewing into the atmosphere 10 years from now let alone 50.

My point is, if we knew with a high degree of certainty what population or carbon emission trends were going to be, then we would be much better off, even if the trends were threatening and unavoidable. We could prepare and adapt. We’d know where to spend finite resources. The uncertainty matters almost as much as the trends themselves. From a political and business perspective, uncertainty is a bad thing. You don’t want to spend billions on one technology unless you know the regulatory and financial context will support it.

We should do a better job emphasizing the monstrous amount of uncertainty that comes with such projections, and the climatological consequences of those figures.

Furthermore, surrendering control over how we respond to the threat of global warming (or population growth) to forces that are themselves unpredictable — I’m talking about the free market if you hadn’t figured it out — doesn’t make a whole lot of sense. It only multiplies the uncertainty. If, however, we can assemble a regulatory environment that takes advantage of those elements of the marketplace that do exhibit predictable behaviors, then we stand a fairly good chance of bending the curves that frighten us into something less fearsome.

This has bearing on the debate over cap-and-trade vs. taxes.

8 Replies to “Change is the one constant”

  1. If sub-Saharan Africa is having trouble feeding and providing water to 880 million people today

    I would argue with this: sub-Saharan Africa is exporting large amounts of food, grown with vast amounts of water. They can probably support their own population, they just can’t also support the exports needed to pay their national debts. The people sub-Saharan Africa is having trouble feeding are us.

  2. As long as the countless thousands of consensus climate change scientists are vastly outnumbering the climate change protesters in the streets and as long as they are not marching with us and acting like it’s the crisis they say it is, the court of reality declares the CO2 affair a tragic exploitation and exaggeration that needlessly condemned billions to catastrophic end.
    Meanwhile, the UN had allowed carbon trading stock markets run by corporations and politicians to trump 3rd world fresh water relief, starvation rescue and 3rd world education for just over 25 years of climate CONTROL instead of the obviously needed POPULATION control. This wasn’t about a climate change; it was about controlling a changing climate with taxes and sacrifice and we former believers promise you that history will call this a dark age for environmentalism. The end REALLY IS near, but not for the planet, but rather the entire climate change movement and criminal charges “will” come as a result. Politicians love to lay blame.
    Climate change science has done to science what abusive priests did for the Catholic Church. You lab coat consultants abused our trust, exaggerated and exploited with 25 years of needless panic. Criminal charges can’t help but be laid as we watch CO2 consensus governments start to fall and or be challenged.

  3. “as long as they are not marching with us and acting like it’s the crisis they say it is”


    The doctor who tells a patient that they are in danger of dying of liver failure is acting like it’s the only crisis, even if there are millions of people in danger of starving to death.


    Because the doctor is concerned with the health of their patients.

    Likewise, there is death, disease, famine and disaster all around, but since they have nothing to do with AGW, the climate scientists being asked about AGW won’t mention them.

    Not because they don’t exist, but because it’s irrelevant.

  4. I would agree with what you are saying. I do think that the climate is not constant and that we are uncertain of what it will be. We cannot say what the exact climate will be ten years from now. I do think that if we continue to treat the earth the way we are now though, we can say with a certainty that the climate will continue to get worse. That is why I agree with what you are saying of how we should prepare and adapt for the future. We have the resources to be greener; the cost of those products is the reason why more people are not using them though.

  5. “We cannot say what the exact climate will be ten years from now”

    Because we have human activities which are self-driving now making a viable impact on the climate.

    “the cost of those products is the reason why more people are not using them though.”

    They’re buying petrol despite a huge increase in prices. It’s not cost that’s stopping them, it’s ideology. Even if of the “STOP BLAMING ME!!!” type.

Comments are closed.