Tag: population growth

Prosperity and World Population Growth

Readers of Matt Ridley’s The Rational Optimist and Ronald Bailey’s columns in the Reason magazine will not be surprised to hear that the rate of population growth is slowing—dramatically—throughout the world. Jeff Wise’s article in the Slate magazine, “About that Overpopulation Problem,” revisits that familiar territory and makes some interesting points. Ultimately, however, Wise fails to appreciate the real reasons for the fall in population growth rate.

First, the good news. As Wise notes, “[The] rate of global population growth has slowed. And it’s expected to keep slowing. Indeed, according to experts’ best estimates, the total population of Earth will stop growing within the lifespan of people alive today. And then it will fall… the long-dreaded resource shortage may turn out not to be a problem at all.”

“For hundreds of thousands of years,” Wise’s article continues, “in order for humanity to survive things like epidemics and wars and famine, birthrates had to be very high. Eventually, thanks to technology, death rates started to fall in Europe and in North America, and the population size soared. In time, though, birthrates fell as well, and the population leveled out.”

Why might that be? “The reason,” Wise avers, “for the implacability of demographic transition can be expressed in one word: education. One of the first things that countries do when they start to develop is educate their young people, including girls. That dramatically improves the size and quality of the workforce. But it also introduces an opportunity cost for having babies.”

True enough, better education is a by-product of development, but where does development come from?

For that we have to look to Ronald Bailey. As he writes, “In 2002, Seth Norton, a business economics professor at Wheaton College in Illinois, published a remarkably interesting study on the inverse relationship between prosperity and fertility. Norton compared fertility rates of over 100 countries with their index rankings for economic freedom and another index for the rule of law. ‘Fertility rate is highest for those countries that have little economic freedom and little respect for the rule of law,’ wrote Norton. ‘The relationship is a powerful one. Fertility rates are more than twice as high in countries with low levels of economic freedom and the rule of law compared to countries with high levels of those measures.’”

And, “Economic freedom and the rule of law produce prosperity which dramatically lowers child mortality which, in turn, reduces the incentive to bear more children. In addition, along with increased prosperity comes more education for women, opening up more productive opportunities for them in the cash economy. This increases the opportunity costs for staying at home to rear children. Educating children to meet the productive challenges of growing economies also becomes more expensive and time consuming.”

So, education is a proximate cause of population growth slowdown. The ultimate cause, however, rests with economic freedom and resulting prosperity.

Comments on Criticism of Cato Ad

Our friends at www.realclimate.org and www.ryanavent.com have been taking shots at the statements in our ad, so I’d like to offer a little commentary.

We make three factual assertions.

First, we say that “surface temperature changes over the past century have been episodic and modest”. We cite Brohan et al., Journal of Geophysical Research (2006 and updates) and Swanson and Tsonis, Geophysical Research Letters, 2009. The first is the latest update of the East Anglia temperature history, which long has been the IPCC staple. It is the one most cited over the years by the IPCC because it was the first long history that contained much more than simply World Weather Records data updated with local records at the end of a month. At any rate, both it and other global histories indeed show modest warming, about 0.8degC from 1900-2000, and indeed it is episodic. Everyone (well probably almost everyone…there are some real people who don’t believe it is right) pretty much agrees that there are two periods of warming, 1910-45 and 1977-98, with a slight cooling in between and no trend after. If that’s not “episodic”, I don’t know what is. The Swanson paper in fact specifically quantifies these episodes. The paragaph near the end of it that says this may mean that warming will be faster than we thought was pure speculation. It could just have easily been argued (as I do) that the lack of recent warming more likely indicates that 21st century warming will be lower than forecast by oceanic feedback because lack of warming simply delays any water vapor amplification. Pure and simple.

The second assertion is that, “after controlling for population growth and property values, there has been no increase in damages from severe weather events”. The citation is short – a note in the Bulletin of the American Meteorological Society, by Pielke Jr. et al, 2005. The et al. numbers over ten other large-name scientists/analysts, and the reference list is the important part. There are a large number of citations on climate-related damages for various places and/or periods. We couldn’t list them all in this format, so we chose a single citation that could be consulted and an interested reader would find all the subsidiary supporting material.

Finally we state that “the computer models forecasting rapid temperature change abjectly fail to explain recent climate behavior”, citing Douglas et al., International Journal of Climatology, 2007, which showed the major disparity between forecasts of the upper tropospheric tropical “warm spot”, a hallmark of greenhouse projections, and observations in the radiosonde record. Yes it is true that Santer et al. have published a lengthy rebuttal, but it is extremely dense and marks just another go-round-and-round over this issue. Douglas et al. have a response but it hasn’t been published yet. The debate will go on and on. Further, it is quite apparent from comparing midrange multimodel estimates from the IPCC to observed temperatures, and those indeed projected for coming years, that there is a signficant disconnect developing between the models and surface temperature. They simply don’t anticipate multidecadal periods without warming. Oh yes, since this has happened, all of the sudden models can be forced to “explain” it, but that’s not prospective. Instead, it is retrospective adjustment. Such work wouldn’t be performed if there weren’t something wrong.

That’s more than enough to negate President-elect Obama’s statement that “The science is beyond dispute and the facts are clear”!