"Malthusianism is a school of ideas derived from the political/economic thought of the Reverend Thomas Robert Malthus . . . which describes how unchecked population growth is exponential while the growth of the food supply was expected to be arithmetical. Malthus believed there were two types of "checks" that could then reduce the population, returning it to a more sustainable level. He believed there were "preventive" checks such as moral restraints (abstinence, delayed marriage until finances become balanced), and restricting marriage against persons suffering poverty and/or defects. Malthus believed in "positive checks", which lead to 'premature' death: disease, starvation, war, resulting in what is called a Malthusian catastrophe. The catastrophe would return population to a lower, more "sustainable", level. The term has been applied in different ways over the last two hundred years, and has been linked to a variety of other political and social movements, but almost always refers to advocates of population control." - http://en.wikipedia.org/wiki/Malthusianism
"A cornucopian is a futurist who believes that continued progress and provision of material items for mankind can be met by similarly continued advances in technology. Fundamentally they believe that there is enough matter and energy on the Earth to provide for the ever-rising population of the world." - http://en.wikipedia.org/wiki/Cornucopian
I used to be Malthusian, which is where I got my die-hard environmental beliefs. And in fact, maybe there is still something to it - we have sort of put in checks on population growth in Canada. Educating women leads to declining birth rates, I gather; we've done an OK job at this in Canada. The birth rate in 2011 in Canada was 1.61, well below the replacement rate.
Of course, Canadians have far higher CO2 emission rates per capita (16 tonnes) than the world average (4.9 tonnes). I'd imagine we consume more resources as well. But I'm assuming that development will continue on this path. The major question is whether technological development will outpace demand for resources.
If I were a paid consultant I would do better research, but for simplicity's sake I like to consider just whether we can make renewable electricity work. If we can get that, I further claim that we will soon be able to rely on clean electric cars & trucks. That's a huge gain. Keep slapping on environmental law as the dangers become more apparent, and we should be able to move ever closer to a zero-waste economy, where the waste from every process is used as the input into another process.
I think we're going to make it to a place where we have clean and reliable access to renewables in my lifetime (that is, by 2070 or so). And the (current) answer lies in capacitance.
I'm relying entirely on a few Economist articles as my evidence, but they make a compelling case for the feasibility of capacitance. The second article even makes explicit the possibility of consumer-grade power storage for off the grid types. These are exciting days.
Wikipedia: Pumped-storage hydroelectricity, our current system
The Economist: The future of energy: Batteries included? (Feb 2 2013) - storing electricity in giant vats of liquid
The Economist: Electricity storage: Pumping heat (March 12 2014) - storing electricity in giant silos of gravel and pressurised argon, or tiny silos for the consumer grade version
The Economist: Can parallel lines meet? (March 8 2014) - using DC to transmit power further with less power lost to line resistance