The Cumulative Impacts Problem

Editor's Note—The Cumulative Impacts Problem
by Nancy Myers & Joe Guth

The problem of cumulative impacts is simply stated. As Peter Montague put it in his preview of the article we excerpt in this issue of the Networker, “Actions that are tolerable or even harmless at the individual level can degrade the planet if thousands or millions of people do them.”

But simple is not always obvious, nor are simple problems simply soluble. Peter reported that, although a few scientists and legal scholars had begun to “nibble around the edges” of the cumulative impacts problem, the recent analysis of Joseph H. Guth, a biochemist and lawyer and SEHN’s legal director, “constitutes a real breakthrough.”

Joe’s breakthrough can be summarized in three points and two pictures. As Peter put it,

1. We have always assumed that we could tolerate unlimited small increments of harm as byproducts of economic growth.

2. But now things have changed because numerous studies are telling us that the cumulative impacts of our economic activities are degrading the Earth's capacity to support humans.

3. Therefore, humans will have to abandon the use of cost-benefit analysis to justify individual environmental impacts and, instead, focus on limiting our cumulative impact to a sustainable size.

The pictures—which expose a fatal flaw in the reasoning on which our environmental law and policies have been constructed--are in the excerptedarticle below, which you will want to read to capture the power of the problem as well as the promise of real solutions to it.

Then we hope you will read the full article, which appeared in print just last month in the Barry Law Review isavailable here. It is already making waves in the legal community.

Our condensed version focuses on regulatory law, an area familiar to environmental advocates. What is missing—and a reason for reading the whole law review article--is Joe’s fascinating discussion of the role of common law (court decisions), both in perpetuating the myth of the limitless earth and in offering alternative precedents that favor the earth, health, and future generations. The arguments Joe presents in the article, based on old cases and today’s realities, are raised by several pending common law cases on global warming.

The scientific, legal, and advocacy communities can work together to attack the problem of cumulative impacts. It’s high time.

II. Cumulative Impacts: Death-Knell for Cost-Benefit Analysis
by Joseph H. Guth

Excerpted from Barry Law Review Volume 11, pages 23-57 (2008), published July 2009. Download full article with documentation here.

The ground is shifting beneath property and environmental law. A new reality is undermining the assumptions those laws are based upon. We have long assumed we can tolerate the endless growth of small increments of environmental damage in the pursuit of economic growth. But now, the mounting cumulative impact of the human enterprise is threatening the long-term habitability of the biosphere. 

To maintain a functioning biosphere in which humans can prosper, the law must turn its attention to the problem of cumulative impacts. The law will have to abandon its use of cost-benefit analysis to justify individual environmental impacts and instead adopt the goal of maintaining the functioning ecological systems that we are so dependent upon. 

Scientists from around the world are reporting that ecosystems in virtually all regions of the Earth are being degraded at unprecedented rates. Just a few recent examples reveal the depth and scope of these reports. 

•    In 2005, the Millennium Ecosystem Assessment, a study compiled by over 2000 scientists from ninety-five countries, demonstrated that 60% of global ecosystem services are “being degraded or used unsustainably,” including fresh water supplies, capture fisheries, air and water purification, and the regulation of natural hazards and pests. 

•    In 2007, the United Nations concluded that current environmental trends threaten human development and overall wellbeing. It established that humanity’s overuse of ecological resources is degrading many elements of the environment; that thresholds of sudden irreversible change are now being crossed, causing the collapse of fisheries, dead zones in the sea, regional climate change, and loss of species; and that it is difficult to know exactly where other thresholds may lie or when they may come upon us. 

•    The World Wildlife Fund and its collaborators have calculated that, according to their measure of humanity’s growing “Global Ecological Footprint,” by the 1980s we had reached the capacity of the biosphere to provide resources and absorb waste and by 2003 had overshot that capacity by 25%.   

These reports also reveal the cause of our ecological problems: the cumulative impact of the myriad human activities that comprise the human ecological footprint. Billions of people acting individually and together in economic enterprises contribute to ecological degradation by causing a wide variety of impacts on the Earth: climate disruption from greenhouse gas emissions, deforestation (for logging and agriculture), degradation of productive land (from desertification, erosion and other processes), loss of freshwater watercourses and unpolluted water supplies for human use, depletion of marine fisheries (through overfishing and destructive practices), discharges of toxic pollution (into air, water and land), biotic impoverishment from loss of species, and overfertilization with nitrogen leading to dead zones in the seas.

Plainly, our property and environmental laws are not adequately protecting the Earth’s ecological systems. As longtime leading American environmentalist James Gustave Speth puts it, despite our current laws “we are losing the planet.” There is widespread agreement that the U.S. and international legal systems are simply not up to the task of controlling the mounting cumulative environmental impacts lying at the root of U.S. and global ecological degradation. The question is why.

The Overarching Structure Of U.S. Environmental Decision-Making 

Our current property and environmental law, including both federal statutes and the common law, harbors the presumption that economic activity generally provides a net benefit to society despite any accompanying damage it may cause. Grounded almost invisibly in this starting presumption, most of our property and environmental laws permit interference with economic activity only where that starting presumption is proved false, that is, where a particular activity can be demonstrated to fail to provide a net benefit to society. 

These laws for the most part do not forbid damage to human health or the environment. Rather, even when fully enforced they permit protection of human health or the environment only where the benefits of doing so can be proved to outweigh the costs. The theory is that this structure ensures that the legal system will not intervene in the economy unless the intervention will increase net social welfare. So it is that cost-benefit analysis has become the legal system’s primary tool for deciding when economic activity may be regulated in the interest of protecting human health and the environment. 

The allocation of the burden of proof to government and plaintiffs has an enormous impact on environmental decision-making. Because of this allocation, the law permits damage to the environment not just when it appears cost-benefit justified but also whenever regulators and plaintiffs cannot carry their cost-benefit burden of proof. In cases of doubt or missing information, the law defaults to its starting presumption: it allows the damaging activity to continue. This allocation of the burden of proof transforms doubt and missing information into a barrier to legal protection of human health and the environment. This explains why industrial interests are rationally motivated under our legal system to invest in the manufacture and spread of doubt and confusion.

A simple diagram can represent the law’s prevailing structure for resolving conflicts between economic and environmental interests, as well as the economy this legal structure promotes. Figure 1 illustrates ever-growing social benefits produced by an exponentially growing economy (upper line). It also illustrates the growth in the accompanying cumulative environmental damage that the law permits by imposing on government and plaintiffs a cost-benefit burden of proof (lower line). This lower line might be thought of as depicting the growth in society’s ecological footprint. 

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What is missing from this environmental decision-making structure is any recognition that the Earth has a finite and limited ability to sustain ecological damage, and that exceeding this limit will inevitably degrade the Earth’s ecological integrity. The reasons for these limits are plain. The Earth has a finite physical size, so that environmental damage becomes concentrated as it accumulates. The deep interconnection between the various constituents of the biosphere causes our various impacts to interact, each compounding the effects of the others. Moreover, species and ecosystems can be replenished only very slowly if at all, so that their losses accumulate with the passage of time.

A simple diagram can depict this ecological limit, too. Figure 2 includes a horizontal line that represents the finite limits of the Earth’s ability to sustain ecological damage. This is a limit that our current legal system is utterly blind to.

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Thus we see the fatal flaw inherent in our system of environmental decision-making. Routinely allowing all environmental impacts except those proved to fail a cost-benefit test, it permits those impacts to grow without limit even when their cumulative effect results in ecological overshoot. Many of these impacts occur not because they actually satisfy the law’s cost-benefit test but because whenever we do not know enough, the law’s default structure permits them to continue.

Even when cost-benefit analysis can effectively evaluate impacts when we are far below ecological limits, it cannot do so once we exceed those limits. Each incremental impact, if taken alone in an empty world, might have caused cost-benefit justifiable harm or even, in many cases (such as carbon emissions), no harm at all. But under conditions of ecological overshoot each incremental impact contributes to a total loss that is immeasurable. Indeed, the permanent loss of the ecological integrity of the Earth, since we need it to survive and prosper, might fairly be considered an infinite loss.

This immeasurable or infinite loss simply cannot be meaningfully allocated among the various increments of damage. For how can the cost to humanity of the ecological devastation of the Earth be allocated among the particular carbon emissions, filling of particular acres of wetlands, destruction of particular fisheries, felling of particular stands of trees, or the fertilizer contributions of particular farmers to dead zones in the sea? How can the value of individual species be calculated when the loss of each contributes to the unraveling of the web of life? How can liability for making the Earth uninhabitable to us be allocated among the thousands or millions of small increments of damage?

Containing Cumulative Impacts in Environmental Decision-making

Legal writers have long called for the law to recognize ecological limits and to be reoriented so as to address environmental problems from an ecological perspective. For the law to do this, it will have to adopt a new decision-making structure that reflects a new set of goals and assumptions.

The essential first step is for the legal system to adopt as an overarching objective the maintenance of the ecological integrity of the biosphere. Under such a governing principle, the law would not evaluate each increment of damage through a particularized cost-benefit analysis. Instead the law would recognize a standard of ecological integrity that it would protect from invasion by environmental impacts large and small.

One expression of a legal principle of preserving ecological integrity is the recognition and establishment of environmental rights. Various forms of environmental rights have been proposed and sometimes even incorporated into the law. For example, legal scholars have called for the recognition and creation of human rights to a clean environment within constitutions, including the United States constitution, and some states have adopted such provisions. Some writers have called for rights of future generations to a clean environment. Still others have urged that our ethical responsibilities to the natural world transcend purely human interests and require creation of rights in nature, including not just biological species and individual organisms, but also ecological entities such as forests and rivers.

Recognizing and establishing these kinds of rights is a critical and valuable step, one that requires care if the rights are to be effective. But even once such rights are recognized, the real legal work has only just begun. What remains is the central problem in any system of legal rights: defining the scope of these rights as they inevitably come into conflict with other rights and interests. Such conflicts are usually resolved by judges in constitutional litigation, though the fate of environmental rights in such cases is today uncertain at best.

This problem is illustrated by a recent case in which the Pennsylvania Supreme Court considered the environmental rights enshrined in the Pennsylvania Constitution. The state constitution expressed Pennsylvanians’ far-reaching rights to a healthy environment, the importance of future generations, and the state’s public trust obligations. The court, however, was unwilling to fully enforce these rights according to these aspirational terms, and instead balanced them with other interests. As the court said: “In this case, we are required to weigh the governmental obligation to protect the environment against the individual right to do as one wishes with property one owns.”

The court found that the Pennsylvania statute at issue may have constituted a taking that impermissibly invaded existing landowner property rights, and reversed and remanded on this question. Thus, faced with what it characterized as a conflict between constitutional environmental rights and traditional property rights, the court reverted to the law’s prevailing structure for resolving this conflict. For Pennsylvania’s environmental rights, or any other aspirational constitutional environmental rights, to effectively stem the onslaught of cumulative impacts, courts will have to strike a far different balance between those rights and other interests.

Cumulative Impacts In Environmental Legislation

The federal government has begun to recognize the problem of cumulative impacts, though in limited ways. Some small administrative efforts are underway. For example, the U.S. EPA is developing a framework for performing risk assessments of the cumulative impact of multiple chemical exposures. The White House Council on Environmental Quality has begun to develop methods for evaluating cumulative impacts in Environmental Impact Statements and Environmental Assessments of government actions under the National Environmental Policy Act of 1969 (NEPA). These are welcome efforts, but they are being undertaken entirely within the context of the existing statutes. They do not, as they could not, dislodge the goals, assumptions and burdens of proof embedded in the decision-making structure of the federal environmental laws.

However, far more importantly, existing environmental laws contain examples of environmental or health standards that reflect a concern with cumulative impacts. Here are some examples:

1. Clean Air Act National Ambient Air Quality Standards

Each of the primary National Ambient Air Quality Standards (NAAQS) of the Clean Air Act defines a health-based standard of air quality for a particular pollutant without regard to cost (though determining the proper standard is typically difficult and fraught with controversy). When regions are out of compliance with a NAAQS, states must develop a State Implementation Plan for bringing the region into compliance. States must inventory existing emissions, project their future growth, decide what control strategies to employ, and then allocate emissions reductions among the sources. While the Clean Air Act permits consideration of costs and benefits in many of these implementing decisions and many regions continue to struggle to come into compliance, the law requires eventual attainment of each NAAQS in every region of the country. Cost-benefit analysis may not be used to justify excessive cumulative emissions if a region is failing to meet the NAAQS.

2. Clean Water Act Water Quality Standards

A second example is the water quality standards that apply to ambient waters under the Clean Water Act, which were introduced earlier. Like the NAAQS, water quality standards specify the levels of particular pollutants that are intended to be safe for the ambient environment, in this case for designated water uses. When a water body or segment of a river is out of compliance with a water quality standard for a toxic pollutant, then a state must develop a control strategy that will produce a reduction in the emissions among all the relevant dischargers to achieve compliance with the standard. Similarly, when a water quality standard for a nontoxic pollutant is not met in a water segment, states must establish the Total Maximum Daily Loading (TMDL) of the pollutant and develop a comprehensive assessment of the reductions that will be necessary among all the dischargers to achieve that TMDL.

There are many difficulties, both legal and technical, with implementing these provisions of the Clean Water Act. But the law’s focus is on the health of the water body or stream segment, not on the costs and benefits of individual industrial discharges.

3. The Endangered Species Act

A third example is the Endangered Species Act (ESA), which protects threatened and endangered species without regard to cost-benefit balancing. Once regulators can demonstrate that species are “endangered” or “threatened” as defined under the Act, the ESA requires the Secretary of the Interior to develop and implement a recovery plan for the species, requires all federal agencies to ensure that their actions are not likely to jeopardize the existence of the species or result in the adverse modification or destruction of critical habitat, and prohibits other parties from a variety of activities that would harm the species, including by modifying habitat.

One of the most famous cases in modern environmental law, which enjoined completion of the Tellico Dam to save the endangered snail darter, established that saving a species can involve extensive short-term costs that simply would not be incurred under the typical cost-benefit decision-making structure incorporated into most of our environmental law.

4. Cap-and-Trade Systems

A fourth example is cap-and-trade systems for controlling individual pollutants. One of these is the Clean Air Act’s cap-and-trade system for sulfur dioxide and another is the recent legislative proposal for regulating carbon dioxide emissions. This approach sets a cap on total emissions of a particular pollutant, and then allocates a finite number of permits to discharge defined increments of the pollutant. Ideally, the cap would define a cumulative level of emissions that will not contribute to ecological degradation. In reality, existing economic interests will often be taken into consideration in setting the cap, and these may lead to a cap set too high to protect the environment. But whatever level is chosen in view of all the various competing interests, once a cap is set, a cap-and-trade system is a clear example of defining a standard that the law can protect against ever-growing cumulative impacts.

5. Cumulative Impacts Under the California Environmental Justice Statutes

Finally, a broader, more ambitious approach is underway in California. Between 1999 and 2001 the California legislature adopted three state laws requiring California Environmental Protection Agency (Cal/EPA) to address the problem of environmental justice. Under these laws, Cal/EPA must, among other things, conduct its programs, policies, and activities, and promote enforcement of all health and environmental statutes, so as to “ensure the fair treatment of people of all races, cultures and income levels.” As Cal/EPA has worked to comply with this mandate, a central issue has become the disparate “cumulative impacts” experienced by different populations within the state.

Dr. Amy Kyle, principal academic investigator supporting a workgroup appointed to address cumulative impacts and develop precautionary strategies, has identified Cal/EPA’s central task as moving from the traditional focus on single chemicals, agents, or other stressors to a focus on what is happening in communities, populations, and population segments as a result of the cumulative effect of all such stressors. The law applies to all Cal/EPA health and environmental programs, not just a handful of individual chemicals. By defining a standard of “fair treatment” for all people in California, the law enables and very likely requires the state to assess and to control the distribution of cumulative environmental impacts.

Toward Defining a Standard of Ecological Integrity

These examples of legal standards were mostly designed for isolated environmental or health problems (the California environmental justice statutes do implicate cumulative impacts broadly, but they seek to remedy unfair distribution of impacts rather than contain those impacts to a defined scale.) To control the broader problem of cumulative impacts, the legal system must develop a standard or principle designed to protect the integrity of entire ecological systems and the biosphere as a whole.

This will not be a simple task. We cannot in practice try to recover a world unaffected by human beings, for that world is gone. Nor can we impose a rule of strict liability for literally every impact on the environment. That would make it impossible for people to live on the Earth, for we cannot exist without having some effects on the world to which we belong.

But a standard need not be so absolute. The environmental and health standards discussed above all allow some level of emissions, discharges, or effect on the environment, just not so much as to invade the protected interest or standard as the law defines it. These are not rules of zero impact. Rather, each essentially defines a balance of interests, though that balance is very different from the one struck by the majority of our current property and environmental law. We need to define a standard of ecological preservation that allows us to live on the Earth, but proscribes degradation of the ecological systems we need to survive and prosper.

Ultimately, a principle of preservation of ecological integrity must be defined in terms of ecological science. For in ecology we can discover how to evaluate ecological systems, what impacts the Earth can tolerate, and what we need to maintain and protect from degradation. Ecologists have done much of this work already. For example, Aldo Leopold defined “land health” as the “capacity for self-renewal in the soils, waters, plants, and animals that collectively comprise the land.” To Leopold, “a thing is right when it tends to preserve the integrity, stability and beauty of the biotic community.” Wendell Berry has taught that “land health” is the “one value” that upholds the entire web of life, and that the law must discourage land uses that threaten land health. More specifically, the Swedish government has defined sixteen environmental quality goals and numerous environmental quality indicators that it believes should be achieved and maintained over the long term. The United Nations 2005 Millennium Ecosystem Assessment describes many global ecosystem services that are important to human beings and yet are being degraded or used unsustainably. Within this field reside the scientific principles that can give specific content to the concept of preserving the ecological integrity of the Earth.

Once the law defines a standard for preserving the Earth’s ecological integrity, a decision-making structure must be constructed that will protect this goal. As we have seen in the examples above, whenever the chosen standard is being threatened, all and not just a few contributing actions must be proscribed or limited. In this new legal structure the burden of proof must be placed on those whose actions pose a threat to the environment, because cumulative impacts can never be contained if impacts are permitted in all cases of doubt or missing information. While such fundamental redesign of our legal system may seem complex, legal writers have begun to develop various proposals for new decision-making structures answering this call. Here are six ideas that have arisen already:

• Commentator James Olson has proposed that the common law should require those who have impaired or are seeking to impair any aspect of the global commons that is critical to human needs and ecological sustainability to bear the burden of proof to justify their conduct. (Shifting the Burden of Proof: How The Common Law Can Safeguard Nature and Promote an Earth Ethic, 20 ENVTL. L. 891, 900 [1990])

• Professor Bruce Pardy has proposed a statute that would define a limit to a society’s total ecological impact in terms of permissible types of ecological change, and then proscribe individual behavior that, if extended to all people in society, would exceed that limit.

• I have previously proposed an “ecological tort,” a legal rule of the common law that would presumptively impose liability for impacts on the environment that may contribute to ecological degradation. I have also discussed other elements of such a legal regime, including defining a threshold level of environmental impacts that would trigger placing the burden of proof on defendants, a definition of who should have standing to assert this rule of law, and a temporary affirmative defense for those engaged in a meaningful search for less damaging alternatives.

• TheScience & Environmental Health Network has proposed a Model State Environmental Quality Act for review of government action, which would place the burden of proof on proponents of a project seeking government approval to demonstrate that their project will not contribute to ecological degradation or unfair treatment of any subpopulation.

• Edith Brown Weiss has proposed that environmental rights be granted to future generations, and the Science & Environmental Health Network and the International Human Rights Clinic at Harvard Law School have developed a package of model constitutional provisions and implementing legislation that places the burden of proof on current generations to demonstrate that their actions do not contribute to ecological degradation either now or in the future.

• One final, far-reaching example was recently proposed by the World Wildlife Fund and its collaborators in their Living Planet Report 2006. Concluding that the human footprint has exceeded the Earth’s biocapacity, they propose that a massive cap and trade system be created to manage humanity’s global footprint. They propose that global and regional footprint caps be established, that rights to contribute to this footprint be allocated according to various principles of fairness among the world’s peoples and that the caps then decline to sustainable levels.

These proposals represent the profound transformation in our legal system that we need if we are to preserve the Earth. They reflect the paramount value to humanity of an ecologically functioning biosphere. They redirect the law toward the goal of containing cumulative impacts. They reject a legal structure that evaluates the costs and benefits of each increment of environmental damage. They place the burden of proof on parties whose acts threaten the environment. They set forth new legal structures for all levels of the American legal system. They include model provisions that can be incorporated into state and federal constitutions. Environmental statutes can be built around them, and they are entirely suitable to be adopted by judges as they bring the common law up to date in tort cases.

The central goal of property and environmental law must shift from promoting endless growth in net benefits to maintaining the ecological systems we need to survive and prosper. By adopting such a new goal, the law would transform the shape of the economy. If the law contains the permissible scale of cumulative environmental impacts, the economy would become one that continues to develop but accommodates rather than undermines the ecological systems our welfare ultimately depends on. Cost-benefit analysis might remain useful as we seek less damaging alternatives in a quest to reduce the scale of cumulative impacts, but it could no longer be used to justify limitless increments of ecological degradation.

The key step in establishing such a new decision-making structure within the law is to define a principle or standard of ecological integrity that would enable the law to contain the growth of cumulative impacts. We can expect to struggle with this task for many years. It is an element of the “Great Work” that constitutes one of humanity’s greatest historical challenges. But if we want to preserve the ecologically functioning biosphere that we depend upon for so much, we are going to have to define within the law what it is we want to preserve or we will lose it forever to the mounting tsunami of cumulative impacts.