Environmental Kuznets curve for biodiversity conservation

November 26, 2011, 8:40 am
Content Cover Image

Aeiral view of a portion of Oahu, Hawaii, illustrating irreversible ecological destruction. Source:Mila Zinkovarva

caption Environmental Kuznets Curve (PENN State University)

The environmental Kuznets curve (EKC) for biodiversity conservation is a hypothesis describing a particular relationship between economic prosperity and the conservation of Earth’s species. In particular, the EKC predicts a u-shaped relationship between per capita GDP and the proportion of a country’s species that are preserved over time.  Poor countries are expected to have high environmental quality, but subsequent industrialization and concurrent increases in wealth and development lead to destruction of the environment.  Theoretically, this pattern continues only until the point at which countries become wealthy enough to begin investing in biodiversity conservation.  Once that turning point is achieved, the proportion of conserved species is predicted to turn upwards again.  Some empirical evidence, however, suggests that the biodiversity EKC may be an illusion, or at least not valid for all regions.

The environmental Kuznets curve is an extrapolation upon Kuznets earlier work in income inequality, the premise of which is that income inequality diverges when a country is experiencing dramatic wealth increase, and then the trend reverses when a relatively high level of total societal wealth is achieved; this incomes version of the Kuznets theory is not universally accepted among economists and demographers.

Theoretical Foundations

The EKC hypothesis follows from the widely held notion, predominant in neoclassical economics, that wealth actually facilitates conservation (while poverty breeds environmental decay).  This notion relies on the assumption that environmental quality is, in essence, a luxury good, something to be prioritized and afforded only by the rich.  Increases in prosperity are presumed to run hand-in-hand with changes that lead to more environmentally benign societies: development, adoption of more efficient technologies, and a transition from economies based largely in industry to economies based largely on services and information.    Moreover, neoclassical economics assumes that resources are endlessly substitutable.  Thus, for countries wealthy enough to develop substitutes, when one resource runs out, the same level of wealth can presumably be sustained by engineering ways to utilize a replacement resource.  In short, wealth permits prioritization of conservation, as well as the development of technology to achieve it; with enough money, humans can grow and invent their way out of anything.  If one accepts this philosophy, then, as Oxford economist Wilfred Beckerman famously concluded, “the best—and probably only—way to attain a decent environment in most countries is to become rich.” 

Biodiversity Crisis

Today, however, scientists widely acknowledge that we are in the midst of an extinction crisis, by conventional count, the sixth such mass extinction to blight the Earth over the course of her 4 billion year history.  Extinction is a natural phenomenon; in fact, 99% of all species that have ever existed are now extinct.  What sets the current extinction apart, however, is its rapidity and its source. Scientists estimate that extinctions today are happening at a rate 100’s to 1000’s of times faster than the background extinction rate, with the dramatic increase in the rate of extinction being almost entirely attributable to anthropogenic, or human influences.

The sixth extinction crisis can be described as occurring in three phases, coinciding with a) dispersal of man across the globe 50,000-100,000 years ago, b) the onset of modern agriculture roughly 10,000 years ago, and c) the industrial revolution, which spread outward from Europe beginning in the late 18th century. With the increasing influence of man, the wave of extinctions, dubbed a biotic holocaust by Norman Myers, has continued to accelerate.  Current estimates of species loss indicate that as many as 50,000 to 200,000 species may be committed to extinction each year; such estimates represent an annual loss of 0.5 to 2% of all extant species.

Conflict Between Economic Growth and Biodiversity Conservation

The single largest direct driver of extinction is land transformation.  While all organisms modify their natural environments to some extent, humans have been unique in the expanse of their reach, so much so that it is now impossible to find any ecosystem on Earth that has not been affected by man’s influence in some way.  In fact, the global ecological footprint—the amount of ecologically productive land and water (assuming global productivity levels) required to sustainably provide the goods and services humans consume (including absorption of all our waste products)—now exceeds the Earth’s capacity by about 30%.  Because land conversion is driven by growth in the human footprint, it is closely tied to socioeconomic indicators and the consumptive capabilities of populations. These connections have led a number of conservation scholars to argue that there is a fundamental conflict between economic prosperity and conservation of the world’s biota, suggesting not only that increases in the global economy (ie. increases in production and consumption of goods and services) imply increased depletion of global resources, but also that the physical limits of our planet preclude unhindered economic expansion.

Evidence for a biodiversity EKC?

Some evidence exists in support of an EKC for biodiversity conservation; however, recent research suggests that such evidence is deceptive.   Though empirical data on GDP and conservation often seem to demonstrate that rich countries protect biodiversity, closer inspection of these same rich countries reveals that they do not exhibit genuine improvements in conservation.  Many of the richest tropical countries are engaged in continued, rapid deforestation—one of the leading drivers of biodiversity loss worldwide.  In instances where countries have become rich through the extraction and sale of natural resources not directly tied to land conversion (e.g. through production of oil), eventual depletion of the resource will either a) lead to a decline in wealth or b) force countries to turn to activities that require participation in destructive land transformation, thereby increasing the threat to biodiversity.   Moreover, the richest countries (those apparently doing the best job of conserving biodiversity) also tend to exhibit the largest per capita ecological footprints.  Evidence for the biodiversity EKC thus belies continued land conversion in wealthier countries and consumptive practices amongst the rich that contribute to resource extraction, land transformation, and biodiversity loss on a global scale.

Fundamental flaws based upon irreversibility

The environmental Kuznets curve has a fundamental flaw for certain world regions, in that a majority of species may have entered the extinction vortex before the curve direction reverses. An example of this is in Madagascar's Central Highlands, where slash and burn activities by native peoples destroyed not only the bulk of the biodiversity in this region, but completely removed most of the topsoil base needed to regenerate native rainforests. Other examples of this massive ecological destruction are the Hawaiian Islands and Easter Island. The application of the environmental Kuznets curve may be valid in such countries as the USA, Norway, Botswana and Australia, where natural ecological resources are large compared to the human population growth; in such cases the ecological reserves for regeneration may be sufficientlly great to achieve a turnaround.




Busa, J. (2011). Environmental Kuznets curve for biodiversity conservation. Retrieved from


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