Economics is a complicated world. Even if we consider only the world of monetary exchange – financial transactions, wages, the cost of manufacturing, and the price of a product in stores is only part of the equation. One thing that economists have long ignored, however, is how much the “depreciation of natural capital” (that is, “the value of net losses to natural resources, such as minerals, fossil fuels, forests, and similar sources of material and energy inputs into our economy”) should factor into economic calculations of wealth. Understood broadly, this not only includes those material resources mentioned above, but larger ecosystems, and the “goods and services” ecosystems provide to their residents: wildlife.

As Edward Barbier notes in this article published in Nature, accounting for the depreciation of natural capital is not just about protecting wildlife; sometimes that depreciation comes from the exploitation of wildlife. “Thailand is estimated to have lost around one-third of its mangroves since the 1970s, mainly to the expansion of shrimp farming and other coastal development.” This is one of countless examples of how “our economies have been trading one form of capital, Earth’s riches, for another — human riches.” As Barbier notes emphatically, “without accounting accurately for this trade-off, we will continue to have a false impression of economic progress and growth. That is as dangerous as flying an aeroplane into the night without navigation tools or instruments.”