This is sometimes described as an environmental Kuznets curve.
In this case, the hypothesis is that as countries get wealthier they move through
a transition from when the began when they're poor, little pollutants are made.
And as they grow richer, more and more pollution is created.
But then past a certain threshold point, the amount of pollutants actually
decreases. So, if countries can transition from being
poor to being rich, they can move from being low polluting to high polluting and
back to low polluting. There are some different sets of data that
back this up. One famous example is sulfur dioxide.
As the United States got wealthier through the twentieth century, the amount of
sulfur dioxide emitted by American industry increased, but it peaked at
mid-century. Then,
Due to environmental laws and the concerns of individuals, it was decreasing all the
way through to today and it's continued to drop into the twenty-first century.
This is actually not just being observed in the United States.
Sulfur Dioxide emissions follow the same pattern all around the world.
There's this idea that if you have around $5,000 per person in per capita income,
you have a peak in sulfur dioxide production. And as you get wealthier than
that, the amount of sulfur dioxide that, that country produce actually starts to
fall again. We can apply this environmental Kuznets
curve to other environmental issues. One idea too, might be that we talked
about population. And it appears that population growth occurs in this narrow
band between wealthy and poor countries, as the country transitions to a more
developed state. This curve is controversial, however.
Notice how it is really empirical, It's based on observation not on
underlying theoretical concerns. It could be that it's not so much that
it's an increase in wealth that makes the environmental impact come down, but just
the passage of time. Of course, in the United States, we saw a
growth in wealth at the same time as the twentieth century progressed.
It could just be that as people became more enlightened, or technology improved,
or people became more socially aware of environmental issues, that there was the
demand to drop these emissions. And so, it's not actually to do with
wealth so much as a process of time. Another real concern is that it appears
that the environmental Kuznets curve doesn't apply to all environmental
variables. Let's think about calorie consumption, for
example, as we get wealthier that increases at a slower rate but it still
increases. More seriously, we might worry about
things like carbon dioxide production because that changes the nature of the
climate. That appears to increase at a slower and
slower rate but, nevertheless, still increase as countries become wealthier.
So, instead of seeing the curve bend back over, the curve remains quite flat and so
even wealthy countries are very polluting. In fact, the wealthier the country is, the
carbon dioxide the more it pollutes. Another good example might be steel
production. Steel production is showing no signs of a
Kuzenets curve right now. This could be due to building growth in
countries like China, but nevertheless, even developed countries like the United
States is still using a lot of steel. So, it could just be that the impact of
increase wealth, instead of moving down towards lower emissions, in another way
just reached a steady state. So, very wealthy countries are no worse
for the environment than merely wealthy countries.