The Adirondack Council was founded in 1975 and immediately attacked acid rain as a top priority. It wasn’t easy to persuade anyone acid rain was real, especially in states whose economies depended on coal mining and cheap electricity. We needed hard data.

For the past 40 years, New York officials and acid rain activists have focused on ensuring that the data are collected, understood and employed to air pollution.

Thanks to testing by the Adirondack Lakes Survey Corp. and the National Atmospheric Deposition Program (more than a dozen federal agencies and research institutions) we now know what is coming out of smokestacks and tailpipes nationwide. We know where it is landing and how it reacts with soil, vegetation, water and wildlife after it lands. Scientists can model how smokestacks, automobiles, agriculture, construction and diesel equipment interact to create acid rain.

That means, for the first time, scientists can show us real-world examples of what will be saved and what will be sacrificed by proposed air pollution regulations.

Leading acid rain research scientist Dr. Charles Driscoll of Syracuse University described it well in his keynote address to the international conference. Under the new “critical loads” approach, scientists would use chemical, biological, geological and atmospheric measurements to determine how much upwind air pollution it takes to damage the area’s most sensitive plants and wildlife – the “critical load” of pollution.

Want to keep your heritage strain brook trout fishery alive? Then an upwind pollution limit of “x” is needed to safeguard its food, habitat and reproduction. Want to protect the high-elevation forests that shelter an endangered bird? Then a pollution limit of “y” is needed upwind of the mountain tops.

In the Adirondack Park, every lake basin and river valley reacts differently to pollution due to variations in size, soil chemistry, forest type, flow rates, etc. Some lakes with richer-than-average calcium soils around them suffered less damage and have recovered quickly as pollution has decreased. Others have been damaged so severely, it will take 300 years or more for them to regain their chemical balance without additional action.

Biological recovery – the re-population of native plants and animals – cannot happen in our dead lakes and impaired rivers until chemical balance returns. If we hope to accelerate that recovery, additional measures will be needed. Critical loads modeling can and should show us how to do it.

This is quite an improvement. When New York enacted the first acid rain law in the nation in 1985, it had to guess how much good the initial pollution cuts would do. When Congress created the national acid rain program in 1990, it chose to cut sulfur-based air pollution from power plants by 50 percent. Everyone knew 50 percent would help, but not how much. Now, such experiments are no longer needed.

By basing air pollution limits on downwind critical loads, science can tailor pollution controls to protect both public health and the environment. Applying such a standard might be unpopular with industries — at first anyway. It would reveal the need for additional pollution controls in many places.

However, it will also establish a limit to the limits. We will finally be able to answer the perpetual question of the regulated: How much reduction is enough? This question is being asked everywhere on earth today, from Rochester to Paris.

At Acid Rain 2015, we learned that China has reduced the amount of fine particles and sulfur produced per unit of electricity since 2007. But the electric grid is expanding, causing more pollution overall. Plus, nitrogen-based pollutants and volatile organic compounds still threaten human health and the environment, calling for a more comprehensive approach, according to Yu Zhao of Nanjing University.

Stefan Astrom of IVL Swedish Environmental Research Institute explained that acid rain has declined sharply in Sweden, but scientists are trying to pinpoint which of several overlapping regulations did the most good. This would help the European Union replicate only the most efficient controls across northern Europe.

Closer to home, PhD candidate Chuan Tang of Clarkson University (Potsdam, NY) showed that property values dropped significantly on Adirondack homes where acid rain had contaminated the local fishery with mercury. Demonstrating tangible financial harm from contamination of the local food chain is important. It could motivate policymakers to set a new critical load standard to prevent it.

Looking ahead, our success against acid rain will seem like a hollow victory if we allow the same plants and animals to perish due to dramatic changes in our climate. Brook trout, for example, are vulnerable to rising temperatures in rivers and streams. Some changes have already begun. Fortunately, we can apply the same methods to climate that worked to curb acid rain.

New York and the EPA both used a cap-and-trade program to provide financial incentives to those who made the fastest, deepest pollution cuts. This allowed companies to profit by innovations in pollution reduction methods. EPA’s program reached its goals ahead of schedule and for a fraction of the estimated price. Today, nine Northeast states participating in the Regional Greenhouse Gas Initiative are using cap-and-trade for the same purpose.

Thanks to Adirondacker Bill McKibben and 350.org, we know the critical load for carbon worldwide is 350 parts per million, suspended in the air. Cap-and-trade can get us there in the quickest, least expensive way.

Perhaps the best indication that the Adirondack Park is recovering from its long, acidic nightmare can be found in a single fish story.

Left: Healthy Trout gillls
Right: Trout gills damaged by acid rain

Silver Lake lies in the heart of the Silver Lake Wilderness Area. Back in the 1970s, it was considered dead. More than half of its adult fish had suffocated from gill damage caused by acid rain. Its pH remained too low to accommodate reproduction.

Today, it has recovered its chemical balance. Fish are thriving in it again. People are again enjoying the benefits of its clean water. In May of 2013, a surprised angler, Rick Beauchamp of nearby Mayfield, hooked and landed a six-pound, 22.5-inch brook trout there.

That’s a big brookie. It set a new state record. If we act now on climate, the next generation of brook trout will have a fighting chanceto survive too.