In the early 1960s, a visionary American scientist named Gene Likens and his team were the first to show that acidified precipitation was damaging to ecosystems and human health, and this harmful “acid rain” was the direct result of smokestack and other emissions. Likens knew, however, that this breakthrough was just the beginning of the effort to address air pollution in the United States. So, since acid rain had serious implications for trees, soil and water on properties The Nature Conservancy had worked so hard (and spent so much money) to preserve, Likens turned to our organization to help find a solution to this avoidable threat. TNC took a pass. 

• Clean air and clean water consistently poll as the top two environmental issues that people care about; and discussion of “clean air” has been identified by the Conservancy as among the most effective that can be used in our communications. 
• Support for measures that contribute to healthy air, like clean water, continues to be very strong among important U.S. constituencies such as urban and suburban families, polling much higher than other concepts like “biodiversity.” 
• The media, too, find clean air of much greater interest than many ecology issues; TNC’s mercury work has, in the last few years, generated no fewer than four major articles in The New York Times. 
• While the United Nations Environment Programme’s (UNEP) climate efforts have met with intractable resistance, UNEP’s ongoing work toward an international mercury accord remains the only major global environmental treaty of the last decade. 
• Since the Clean Air Act, air policy in the United States has centered on human morbidity and cost benefit analyses. The recent U.S. EPA Mercury and Air Toxics Standards rule (MATS) — which includes a call for reducing atmospheric mercury levels by 90% by 2015 — has been estimated to initially prevent 11,000 premature deaths, 2,000 cases of chronic bronchitis, 4,500 heart attacks, 130,000 asthma attacks, 5,700 hospital and emergency room visits and 3,200,000 restricted activity days annually in the United States. All at a savings of $30-90 billion. 
• TNC’s science work on air issues has also helped to insert the value of air pollution impacts on wildlife and ecosystems into the equation. A recent study, for instance, showed that pest suppression alone by bats in the United States — a species we now understand is greatly threatened by mercury pollution — is valued up to $50 billion per year. 

And, of course, air pollution continues to affect the lands and waters that support life. In January, the Biodiversity Research Institute and the Conservancy released a report called “Hidden Risk,” synthesizing the available information on what we know about mercury in the terrestrial food web. As recently as five years ago, much of this information was unavailable or hypothetical. Thanks to funding from RJKOSE and other private grants and donations, the Conservancy has been taking a leadership role in the unfolding scientific story of disentangling the transport and fate of mercury in the terrestrial food web. 

The report’s results showed enormous risks to bats and songbirds, several species of which serve as important indicators of mercury availability in key habitats (and could thus play a critical role in monitoring the changes that will come if the MATS rule survives inevitable litigation). Mercury deposition is more pervasive in these systems than we thought possible just a few short years ago, and thus of ongoing concern to our conservation work. In addition, mercury pollution in nature continues to be of great interest to the public: The report received front page coverage in The New York Times science section. 

All well and good, you might say; but still not a compelling case for the Conservancy to make air pollution a priority at a time when we have scarce resources and it has renewed federal attention. We counter that this is a critical moment for TNC and other NGOs to take the lead in the following areas: 

• Broadening Scientific Understanding: “Hidden Risk” is part of a vibrant and essential ecotoxicology research movement. The more we look, the more we find, particularly with regard to mercury’s impacts on nature. We need to continue investing in this research. 
• Raising Awareness and Building Support: Air pollution is a global problem for nature. Most of the mercury that falls in the United States now comes from China, not the American Midwest. Most of the nitrogen emitted into the U.S. atmosphere ends up in Europe. With our basis in science, TNC and similar science-based NGOs are uniquely positioned to raise awareness of the scope and scale of the air pollution problem in nature — and use their memberships and constituencies to build support for action and protective policies. 
• Evaluate Policy Effectiveness: In the United States, we need to fill critical gaps in tracking key air pollutants, particularly a more robust system for tracking mercury contamination. We also need to establish clear thresholds for major air pollutants to know if our policies and regulations are good enough. Europe has figured out how to set such thresholds (called critical loads) across multiple countries for over a decade and have them inform policy. 
• Evaluate Management Effectiveness: Landscape management actions (such as promoting cooler prescribed burns and preventing catastrophic wildfires that release more mercury from the soil) are among a range of management actions that could help reduce mercury emissions into the atmosphere. While we are just beginning to understand the full range of these actions, land managers including the Conservancy can and must play a role in building this knowledge. 

Once it was revisited and revised, a much improved Clean Air Act dramatically decreased the amount of acid rain in North America. As a result, fish returned to some lakes and streams in the Adirondack Mountains where not so much as one fish had been seen for over a generation. 

But more needs to be done. The law's original authors envisioned periodic upgrades in the Act; but there hasn’t been one for over 20 years. Those same fish that benefited in the Adirondacks (and many more across the northern United States) still cannot be safely consumed because of high mercury levels and are particularly dangerous to children and women of childbearing age. Today, air pollution in the United States continues to cause more premature deaths than AIDS and gun violence combined. 

However, the political climate has also become more toxic. In 1970, the Clean Air Act overwhelming passed both chambers of the U.S. Congress, then controlled by Democrats; but with considerable bi-partisan help, it was signed into law by a conservative Republican president. Today, few Democrats mention clean air, while Republicans’ “jobs agenda” consists of plans to weaken or dismantle environmental regulations (many of them air-related). While the Conservancy has no intention of joining a partisan squabble, there is ample need for non-confrontational, science-based approaches to making sound policy arguments that benefit people and nature. 

It’s time the Conservancy finally took Gene Likens up on his offer to become players in the effort to ensure clean, healthy air for all — not only for people, but for nature too.