The interview with John Houghton was very good until the last paragraph. “What will the cost of action be?” Houghton asks, and then answers, “less than the loss of one year’s economic growth over 50 years.”
One serious problem inherent in Houghton’s assertion is that exponential economic growth is not sustainable. (The economic growth may stem from increases in population or levels of consumption; at the present time, we have one or the other in most places and both in some.) Establishing that there are limits to growth (of population, economic activity, or most any tangible entity) does not require a computer model or anything other than a sharp pencil and a conscious mind. It is easy to calculate that 210 equals 1024, so 220 is greater than 1 million. The US gross domestic product (GDP) increases an average of about 3.5% annually, so in 50 years it would expand by a factor of approximately 5.6. Is that plausible?
The debate over limits to growth dates back to Thomas Malthus (1766–1834), who treated the question of population, but it did not acquire much urgency until the 1960s, when computer simulations predicted an end to growth for any foreseeable scenario. Obviously, both population and economic activity are limited, but political and cultural values can allow a lot of people to live at the subsistence level or fewer to enjoy affluence. It was only later that the scientific community became aware of chaos and the fact that the modeling of nonlinear systems can be unworkable even for rather simple cases.
How can we generate a numerical estimate for the magnitude of the limits to growth? The ecological footprint, basically an accounting rather than a modeling methodology, provides an answer. The world’s level of consumption is already beyond sustainability. 1
Global warming is merely the crisis du jour. It was not even considered in the computer simulations done more than 40 years ago. That it is a serious potential problem is attested to in a rather cautious statement from the American Geophysical Union. 2 Can it be contained by spending as little as 2% of the annual growth in GDP? For the US, that would amount to about $10 billion in the first year. That may sound like a lot of money. However, some technologies, like carbon sequestration, solve the problem but are untested; others, like fission reactors, are expensive and resource intensive; and some, like fusion reactors, do not exist at all. That $10 billion might be more than enough to cover the cost of research, but it won’t come close to covering the capital investment. Then one needs to add in the problem of global peak oil production, for which time-frame estimates range between 2006 and an optimistic 2030. Rising demand for fuel and the resulting higher prices have increased the use of fuel sources such as coal, tar sands, and synthetic petroleum that produce much more CO2 for each unit of usable energy.
Another challenge to addressing global warming is the need for an unprecedented level of international cooperation, given the conflict between developing and mature economies. What one actually sees happening is a race among nations to claim the seabed that is being exposed by the melting of arctic ice. It is even conceivable that global warming could boost growth by providing access to petroleum and other mineral resources before rising sea levels curtail economic activity.
The scientific community has been derelict in its duties. Economists and politicians have been offering growth as the solution to every conceivable problem that plagues humanity. Except for a very few of us, 3–5 the physicists and other scientists who should know better have not challenged the economists or the politicians.