The chart shows generally the most populous countries have the largest ecological footprint. Of course, that makes sense, more people, and more impact on the environment. World population was greatly affected by the industrial revolution. Improvements in medical knowledge/research, sanitation, food production are all related to industrialism. With mass production, the cost of things dropped and something as simple as warm clothing and decent shoes helped more people live longer.
But one of the largest impacts on population growth is availability of cheap energy. The planet could not support the 7 billion plus people that exist today without first the commercialization of coal, then of oil and, more recently, gas. Cheap energy expands carrying capacity and population grows. The Green Revolution could not have been produced without large oil and gas inputs. Farm equipment is manufactured and fueled by petroleum. The pesticides and herbicides used to increase production are petro-chemical products. The boats and trains that deliver and distribute food all run on oil. These energy sources have been necessary for the unprecedented population growth that has occurred over the last three hundred years.
Biomass (such as wood) based populations can grow at a slow rate as long as there is frontier land to migrate into. If frontiers are fixed, growth stops and then fluctuates around this new equilibrium. Coal based populations are still growing, as coal production is still growing and is not yet close to peaking. Oil based populations grow quickly at first, but then slow as higher standards of living lower fertility – a phenomenon observed throughout the industrialized world. I hypothesize this is related to the impact of petro-chemicals on health and fertility.
While the commercialization of higher quality energy sources may be very unevenly distributed, the societies that adopt new energy sources, high energy societies, have a profound impact on those societies that remain low energy societies. Less developed countries are often exploited by powerful countries. In addition, the global impact of fossil fuels affects the entire planet. The unfortunate truth is that most of the wealth generated by exploiting the environment unsustainably has gone to a few very powerful people.
Note that the countries that contribute the least to the world’s ecological footprint tend to be island nations. They will be highly impacted by the countries with high ecological footprints as climate change increases intensity of storms and sea levels rise. It is reasonable to assume that unless current energy resource production is increased and new resources are exploited, the population will no longer grow. And if energy resources decline (e.g. a peak in production is reached), then we may see a decline in population. Perhaps that is the natural way, but it will be painful, chaotic and cause political instability.
Political attempts at mitigating carbon dioxide emissions always involve funding for non-industrialized nations. Many people are upset that Americans and other developed nations are footing the bill, but we are one of the nations that have exploited and damaged the environment the most. Ethically, it is the right thing to do.