The impact of mankind's activities on our planet is unquestionably one of the major issues in the 21st century. While it most definitely is a highly subjective topic and everybody has an opinion that ranks somewhere on a scale spanned on either end by Gore and yee-haw, I doubt anyone can argue against the fact that natural resources are finite and that we are (at the very least) using up a non-negligible fraction. Given that a significant portion of the world's population is poor and several developing countries are growing very rapidly, I often wonder about sustainability.
I came across this rather interesting report put together by a bunch of organizations including the OECD and WWF. Using various metrics of carbon footprint, grazing land, used forest areas, fishing, cropland and built-up areas, the report gives numbers related to the ecological footprint of various nations and the world. Paraphrasing from the report "Ecological Footprint (which represents demand for resources) and regenerative capacity (which represents the availability of resources) are expressed in units called global hectares (gha), with 1gha representing the productive capacity of 1 hectare of land at world average productivity." In essence, it is use vs availability. Obviously the metrics are somewhat subjective and open to criticism, but not too unreasonable in my opinion.
With some help from the good wife, I was able to get data from the report and correlate them with per-capita income (adjusted for purchasing power parity, data from UNHD web-site) and came up with a couple of graphs. I have just considered countries with populations of more than 30 million to avoid noise.
Here is Graph 1:
I think the straight line fit is pretty cool. As expected, we have low and middle income African and Asian countries consuming less than the global average and good ol' uncle Sam going to work at the other end of the spectrum. Now, in about 20 years, China is expected to grow almost three-fold and overtake the US as the largest economy and India won't be too far behind. These countries will constitute about half the world's population in that time-frame and will be moving north-east on that graph, doubling the global average consumption by themselves in no time.. oh.. and there will be the little matter of about 500 million people in equally hot Brazil and Russia.
So how about sustainability? Here is Graph 2 (again, countries of pop. > 30 million, with the ratio of "available" to "used" hectares. So, a ratio of less than 1 is bad. Note that this ratio can be less than 1.0 because much like over-drawing from your bank account, you just don't allow regeneration to take place at its natural pace.
Not too unexpectedly, it shows that, as global citizens, we're using up more (50%) than what the planet can regenerate... and this is just in 2010. South Korea and Japan are in scary territory and India and China aren't looking very good given they're expected to grow multiple times.
With better energy sources, more productivity (in developing countries) and change in consumption practices (in developed countries) etc., the outlook can be more positive, but this is nevertheless a very critical issue and needs more serious characterization and attention. Sustainability is becoming a major issue and will soon (if not already) start stifling growth in many developing countries. Herein lies the grandest challenge of all for the two emerging Asian giants.
