Forest rangers in national parts often tell hikers: “Take nothing but pictures, leave nothing but footprints.”
If footprints were all we left on the planet, our environment would remain pristine. But we need to feed and clothe ourselves, travel, heat or cool our homes, and do many other things. In the process, we use up or spoil natural resources – land, water, air, trees, minerals. The amount of natural resources we consume is our ecological footprint.
Nature tries to replenish what we consume and repair what we damage. Unfortunately, this “biocapacity” has limits. According to the World Wildlife Fund, an environmental group, the collective human footprint is 20% greater than the planet's biocapacity. In other words, our present lifestyle is unsustainable.
This is especially true of the amount of carbon dioxide we emit -- our carbon footprint. We release carbon dioxide (CO2), a greenhouse gas, into the atmosphere when we burn coal, oil, and other fuels. Some of it is absorbed by trees and oceans, but our rate of fuel consumption exceeds this capacity. The amount of CO2 in the air has been steadily increasing, and there is overwhelming evidence that this is leading to potentially catastrophic climate change.
In 1997, scientists and policy makers from all over the world got together in Kyoto and proposed voluntary limits on each country’s CO2 emissions. More than 180 countries have adopted these guidelines. Unfortunately, the U.S. Senate unanimously rejected these limits, arguing that they would hurt the economy. The senators were also unhappy that the limits apply only to industrialized nations. Countries such as India, Bangladesh, and China -- which have large populations, and consume a lot of fuel -- are exempted.
To understand why the Kyoto protocol exempted these nations, divide each country’s carbon footprint by its population -- to get its per capita footprint. You will then discover, for instance, that Bangladeshis and Indians emit only a tenth as much CO2 as the biggest emitters – Americans! Chinese emit a little more than Indians, but still much less than Americans. Western Europeans have an emission level about midway between Asians and North Americans. So by this measure, countries in North America and western Europe bear much of the responsibility for rising levels of atmospheric CO2. That is why the Kyoto meeting singled them out for emission limits.
U.S. lawmakers are not the only ones unhappy with the way we calculate the carbon footprint, or the ecological footprint in general. Some feel that it unfairly penalizes countries such as Australia and Canada that have high per capita resource consumption, but also large biocapacities -- in the form of forests that absorb carbon, for instance. They feel that a country's footprint should be measured by the extent to which resource consumption exceeds biocapacity. In this regard, Australia and Canada do great, Bangladesh fares as badly as the US, and Japan fares the worst of all!
So which do you think is the fairest measure of a country's ecological footprint: per capita consumption, total consumption, or total consumption divided by biocapacity?