Collapse: The dozen most serious environmental problems and what we can do about

them
Jared Diamond*

It seems to me that the most serious environmental problems facing past and present societies
fall into a dozen groups. These problems will be explored under four categories:

I. Let’s begin with the natural resources that we are destroying or losing: natural habitats,
wild food sources, biological diversity, and soil.

At an accelerating rate, we are destroying natural habitats or else converting them to human-
made habitats, such as cities and villages, farmlands and pastures, roads, and golf courses. The
natural habitats whose losses have provoked the most discussion are forests, wetlands, coral
reefs, and the ocean bottom. More than half of the world's original area of forest has already
been converted to other uses, and at present conversion rates, one-quarter of the forests that
remain will become converted within the next half-century. Those losses of forests represent
losses for us humans, especially because forests are our sources of timber, paper, and other
essential raw materials, and because they provide us with so-called ecosystem services such
as protecting our watersheds, protecting soil against erosion, constituting essential steps in
the water cycle that generates much of our rainfall, and providing habitat for most terrestrial
plant and animal species. In addition, we are affected not only by forest destruction and
conversion, but also by changes in the structure of wooded habitats that do remain. Among
other things, that changed structure results in changed fire regimes putting forests and
savannahs at greater risk of catastrophic fires. ...

II. The other issue is about ceilings —on energy, fresh water, and photosynthetic capacity. In
each case the ceiling is not hard and fixed, but soft: we can obtain more of the needed
resources, but at increasing costs.

The world’s major energy sources, especially for industrial societies, are fossil fuels: oil, natural
gas, and coal. While there has been much discussion about how many big oil and gas fields
remain to be discovered, and while coal reserves are believed to be large, the prevalent view
is that known and likely reserves of readily accessible oil and natural gas will last for a few more
decades. This view should not be misinterpreted to mean that all of the oil and natural gas
within the Earth will have been used up by then. Instead, further reserves will be deeper
underground, dirtier, more expensive to extract or process, or will involve higher
environmental costs. ...

III. The following problems involve harmful things that we generate or move around: toxic
chemicals, alien species, and atmospheric gases.

−The chemical industry and many other industries manufacture or release into the air, soil,
oceans, lakes, and rivers many toxic chemicals, some of them "unnatural" and synthesized only
by humans (like DDT), others present in the Earth in only small amounts (e.g., mercury), and
still others synthesized by living things but synthesized and released by humans in quantities
much larger than natural ones (e.g., hormones). The first of these toxic chemicals to achieve
wide notice were insecticides, pesticides, and herbicides. Since then, it has been appreciated
that the toxic effects of even greater significance for us humans are those on ourselves. The
culprits include not only insecticides, pesticides, and herbicides, but also mercury and other
metals, fire-retardant chemicals, refrigerator coolants, detergents, and components of
plastics. We swallow them in our food and water, breathe them in our air, and absorb them
through our skin. Often in very low concentrations, they variously cause birth defects, mental
retardation, and temporary or permanent damage to our immune and reproductive systems.
In addition, deaths in the U.S. from air pollution alone (without considering soil and water
pollution) are conservatively estimated at over 130,000 per year. ...

− Human activities produce gases that escape into the atmosphere, where they either damage
the protective ozone layer or else act as greenhouse gases that absorb sunlight and thereby
lead to global warming. The gases contributing to global warming include carbon dioxide from
combustion and respiration, and methane from fermentation in the intestines of ruminant
animals. Of course, there have always been natural fires and animal respiration producing
carbon dioxide, and wild animals producing methane, but our burning of firewood and of fossil
fuels has greatly increased the former, and our herds of cattle and of sheep have greatly
increased the latter. For many years, scientists debated the reality, cause, and extent of global
warming: are world temperatures really historically high now, and, if so, by how much, and are
humans the leading cause? Most knowledgeable scientists now agree that, despite year-to-
year ups and downs of temperature that necessitate complicated analyses to extract warming
trends, the atmosphere really has been undergoing an unusually rapid rise in temperature
recently, and that human activities are the, or a, major cause. The remaining uncertainties
mainly concern the future expected magnitude of the effect: i.e., whether average global
temperatures will increase by "just" 1.5 degrees Centigrade or by 5 degrees Centigrade over
the next century. Those numbers may not sound like a big deal, until one reflects that average
global temperatures were "only" 5°C cooler at the height of the last Ice Age.

IV. The remaining problems involve the increase in human population:

The world’s human population is growing. More people require more food, space, water,
energy, and other resources. Rates and even the direction of human population change vary
greatly around the world, with the highest rates of population growth (4% per year or higher)
in some Third World countries, low rates of growth (1% per year or less) in some First World
countries such as Italy and Japan, and negative rates of growth (i.e., decreasing populations)
in countries facing major public health crises, such as Russia and AIDS-affected African
countries. Everybody agrees that the world population is increasing, and also that its annual
percentage rate of increase is not as high as it was a decade or two ago. However, there are
still divergent predictions about whether the population will stabilize at some value above its
present level, and (if so) how many years it will take for the population to reach that level, or
whether the population will continue to grow.

− What really counts is not the number of people alone, but their impact on the environment.
If most of the world's 6 billion people today were in cryogenic storage and neither eating,
breathing, nor metabolizing, that large population would cause no environmental problems.
Instead, our numbers pose problems insofar as we consume resources and generate wastes.
That per-capita impact—the resources consumed, and the wastes put out, by each person—
varies greatly around the world, being highest in the First World and lowest in the Third World.
On the average, each citizen of the U.S., Western Europe, and Japan consumes 32 times more
resources such as fossil fuels, and puts out 32 times more wastes, than do inhabitants of the
Third World. But low-impact people are becoming high-impact people for two reasons: rises
in living standards in Third World countries whose inhabitants see and covet First World
lifestyles; and immigration, both legal and illegal, of individual Third World inhabitants into the
First World, driven by political, economic, and social problems at home. Immigration from low-
impact countries is now the main contributor to the increasing populations of the U.S. and
Europe. By the same token, the overwhelmingly most important human population problem
for the world as a whole is not the high rate of population increase in Kenya, Rwanda, and
some other poor Third World countries, although that certainly does pose a problem for Kenya
and Rwanda themselves, and although that is the population problem most discussed. Instead,
the biggest problem is the increase in total human impact, as the result of rising Third World
living standards, and of Third World individuals moving to the First World and adopting First
World living standards.

People in the Third World aspire to First World living standards. They develop that aspiration
through watching television, seeing advertisements for First World consumer products sold in
their countries, and observing First World visitors to their countries. Even in the most remote
villages and refugee camps today, people know about the outside world. Third World citizens
are encouraged in that aspiration by First World and United Nations development agencies,
which hold out to them the prospect of achieving their dream if they will only adopt the right
policies, like balancing their national budgets, investing in education and infrastructure, and
so on. What will happen when it finally dawns on all those people in the Third World that
current First World standards are unreachable for them, and that the First World refuses to
abandon those standards for itself? Life is full of agonizing choices based on trade-offs, but
that's the crudest trade-off that we shall have to resolve: encouraging and helping all people
to achieve a higher standard of living, without thereby undermining that standard through
overstressing global resources.

People who get depressed at such thoughts often then ask me, "Jared, are you optimistic or
pessimistic about the world's future?" I answer, "I'm a cautious optimist." One basis for hope
is that, realistically, we are not beset by insoluble problems. While we do face big risks, the
most serious risks are not ones beyond our control, like a possible collision with an asteroid of
a size that hits the Earth every hundred million years or so. Instead, they are ones that we
generate ourselves. Because we are the cause of our environmental problems, we are the ones
in control of them, and we can choose or not choose to stop causing them and start solving
them. The future is up for grabs, lying in our own hands. Nor do we need new technologies to
solve our problems; while new technologies can make some contribution, for the most part
we "just" need the political will to apply solutions already available. Of course, that's a big
"just." But many past societies did find the necessary political will. Our modern societies have
already found the will to solve some of our problems, and to achieve partial solutions to
others.
My remaining cause for hope is another consequence of the globalized modern world's
interconnectedness. Past societies lacked television and archaeologists. Today, though, we
turn on our television sets or radios or pick up our newspapers, and we see, hear, or read about
what happened in Somalia or Afghanistan a few hours earlier. Our television documentaries
and books show us in graphic detail why the Easter Islanders, Classic Maya, and other past
societies collapsed. Thus, we have the opportunity to learn from the mistakes of distant
peoples and past peoples. That's an opportunity that no past society enjoyed to such a degree.
My hope in writing this book has been that enough of us will choose to profit from that
opportunity to make a difference.

*Adapted from Diamond, J. (2005). Collapse: the dozen most serious environmental problems and
what we can do about them. Skeptic, 11(3), 36-41.