I write and lecture occasionally about various aspects of sustainability. I don’t think we have a big problem from population growth or running out of physical resources, as long as we are sensible. It is perfectly possible to support a much larger human population without destroying the environment, by harnessing human ingenuity to improve land productivity and to minimise resource use thanks to advanced technology. There are some obvious limits though. I summarise some in this diagram. As you can see, I don’t think there is room for complacency, but nor do I think the problems are insurmountable, and with willingness, we can ensure a healthy environment.
Personally, I think the problem of man-made global warming has been exaggerated, and I don’t lose any sleep on that issue, but we could still reduce atmospheric pollution generally to good effect. Particulates from fossil fuels, aerosols, HFCs, CFCs and so on could all be reduced. And even if CO2 isn’t an urgent issue yet, it still is definitely a greenhouse gas so we should limit avoidable emissions. However, over-fishing of the oceans is a real and urgent issue. A lot of people rely on fish as their main protein source, and with good fish farming and better fishing practices, we could probably get by OK, but right now, there are some very stupid fishing practices in place, resulting in enormous waste as well as over-fishing. Some species are in real danger, mainly thanks to poor regulation and policing.
Land is often misused too. We may be able to feed more people with less land, but we should still prioritise food production over biofuels and other misuses while people are going hungry. Biofuel production causes a great many environmental problems as well as human ones: incentivising chopping down of forests and draining bogs, increased global food prices and consequent starvation, forced relocation of poor people and probably others I have forgotten. Land that can grow food should not be wasted making fuel for cars and trucks at least until such time as we have eliminated undernourishment for everyone.
Sustainability isn’t just about the environment. We must also ensure that human systems are sustainable too, i.e. we don’t kill each other, or go back to a new dark age, or reduce quality of life potential. It is no easy trick to manage the environment and humanity for mutual benefit, but it can be done. When we look at the whole system, it is tempting to see humanity as the enemy of the environment, but the evidence in the developed world is that by developing new technologies, we can clean the environment up and restore it. So fostering human creativity is one of the keys to achieving sustainability environmentally too.
Many of these human issue are normally ignored in environmental discussions, but things that affect human society often have system wide effects that impact on the environment. Recession, diversion of funds and prioritisation of values have obvious impacts but more indirect impacts are also likely. So we should consider human social and political issues as an important part of the environmental system. Man is part of nature too.