CAUSATION IN ENVIRONMENTAL SCIENCE

What are the causes of environmental problems, and how do scientists approach "understanding" and "solving" them?

Most environmental scientists have chosen to concentrate on "understanding" and "solving" certain of these problems. For example, take the issue of visible injury on leaves of trees in some urban and near-urban areas.

Problem: Visible injury to leaves

Cause: Uptake of the pollutant ozone by leaves

Solution: Spray leaves with a protective compound that decreases this uptake

Should scientists congratulate themselves on having "solved" the problem of visible injury to leaves?

(This scenario is, as Dave Barry would say, "not made up." I conducted a study, years ago, which was funded by a major U.S. manufacturer or plastic polymers, in which I tested the efficacy of certain compounds at protecting leaves against this kind of air pollution-induced injury!)

I argue that this "solution" really treats only the SYMPTOM, and is a relatively superficial solution.

The cause, on a deeper level, is excessive ozone pollution, which is, in turn caused by large numbers of people driving cars and supporting industrial processes that produce pollutants that interact to create ozone pollution.

Typically, traditional approaches have treated symptoms of larger, more fundamental and general problems but may not necessarily have gotten at their root causes.

Further, the "solutions" are usually technological "fixes", rather than being rooted in more fundamental changes.

If this isn't a "real solution," what is, what are root causes of our environmental problems, and why do we fail to recognize and address them, choosing instead to apply "bandaids"?

I'll "tell" you a story and follow it with a question. As I do so, think about what we were just saying about causation:

Bangladesh story:

This small nation, which is East of India along the Bay of Bengal, is commonly hit by hurricanes and major monsson events.

Associated with these storms, there are often huge winds, tidal waves, and rain-induced river flooding

The waters leave homes and farms devastated, with 0.25 or more million people often left homeless, largely those that lived on the coastal deltas.

At such times, the news media reports, "Natural Disaster Strikes Bangladesh" "Storm Leaves Millions Homeless,"and so forth.

The question is: "What really causes these tragedies in Bangladesh?"

To answer, you need some background:

Bangladesh is small in area; about the size of Wisconsin. Yet it has over 100 mill people; about 1/3 as many as in the whole US! It is one of the most densely populated nations in the world and, until recently, was one of the fastest growing.

In these crowded conditions, people have stripped hill and mountainsides of wood for fuel, shelter and food, and their livestock have overgrazed the landscape. When the rains come, soil from naked unprotected land washes into rivers and the rivers flood because thvegetation, that would otherwise take up water, is no longer well-developed.

Silt carried by the rivers is deposited in the deltas where the rivers meet the sea.

Looking for farmland, people move out onto the deltas. However, deltas are inherently unstable and unsafe; deltas belong to the sea, not to people.

Then, when the monsoons or hurricanes come, high runoff or tidal waves flood the deltas and people lose their homes and farms.

So, what causes these tragedies?

There are two levels of causation, just as for acid deposition, described above:

There is the level that the media (and many scientists in case of air pollutants and injury to plants) have tended to focus on: heavy rains or wind (or excessive ozone). This level is the proximate factor. The proximate causal factor answers the question "How?" (How did the people die, how do the leaves become injured?) This factor is causal at the immediate, direct level.

But underlying that, there is a second, deeper cause. Too many people (and in the case of ozone pollution, coupled with heavy use of fossil fuel energy). This level is referred to as the ultimate factor. The ultimate causal factor answers the question "Why?" (Why were people living in a vulnerable spot with denuded hillsides above them?)

My personal contention is that the large size of the human population and its continued rapid growth is an ultimate cause behind nearly every issue that we will discuss this term (for some other opinions, see lecture notes on the history of human population growth).

(To continue scrolling through these notes for a list of some relevant Web links, click the box labeled ">>" at the bottom of this page; to return to previous sections, click the box labeled "<<," and to return to the overall table of contents for the BI301 Home Page, click "CONTENTS." Click "Navigate," here for more information on moving within and among these documents.)

Page maintained by Patricia Muir at Oregon State University; last updated Jan 4, 2009.

 

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