This nation has had a remarkable record in the last half century of science driving successful environmental policy that pays back many times the cost of implementation to the American people. While we work for still-needed improvements in air quality, we should also celebrate our successes.

A group of 11 scientists who have studied the effects of air pollution on ecosystems for decades recently published a paper in the journal Environmental Science and Policy highlighting environmental improvements from cost-effective policy driven by science. I am one of those scientists. While scientific research and monitoring can document environmental degradation, they also can document improvements.

Examples reported in this paper include reductions in air pollutants, such as acid rain, ozone, haze, lead and mercury. For example, since the 1970s there has been a continuous decline in atmospheric deposition of sulfur and nitrogen that cause acid rain in much of the eastern United States. This has resulted in decreasing acidity and aluminum in lakes, streams and soils, including evidence from lakes and soils in Maine.

These improvements are directly attributable to the Clean Air Act and other legislation and are cost-effective. One Environmental Protection Agency report estimates the economic benefits of the 1990 Clean Air Act amendments exceed the costs by more than 30 to 1 between 1990 and 2020.

[Greenland is melting faster than at any time in the past 450 years (at least)]

Removal of lead-based fuel additives from gasoline has resulted in a greater than 95 percent decrease in the concentration of lead in air, a direct result of regulations governing air quality. This is good news because lead is a potent neurological toxin to children and has cardiovascular effects on adults, but lead is strongly held by organic matter in soils and will still remain a concern for decades.

There is tremendous risk to eliminating from policy debates the science — including environmental monitoring from gadgets on the ground to satellites — that informs us of our progress, alerts us to concerns, and prevents the health of our environment from slipping backward.

In Maine, we still have high levels of lung disease, concerns for sensitive ecosystems from ongoing pollution, and ecosystems that will take decades or longer to recover from past pollution. We still have higher levels of air pollution than areas without downwind sources of pollution, and that means there is work yet to be done. And Maine is also experiencing a changing climate.

But imagine our environment and health today had we not made such significant progress.

We should celebrate how science has guided our achievements in reducing atmospheric lead, tropospheric ozone, haze, acids and mercury. It is hard to imagine credible economic arguments to roll back or avoid cost-effective, science-informed, sound environmental policy. Most of us would not hesitate a second to act if the health impacts of dirty air or water were visited on our children or grandchildren, regardless of the costs.

[Opinion: The Penobscot is polluted with mercury. Without the EPA, it would be much worse.]

As for the future of our planet, we should celebrate success stories in air pollution reduction and apply the same wisdom to rising greenhouse gases that are costing Americans more today than ever before. The Government Accountability Office calculated in a recent report that the federal government alone has spent more than $350 billion over the past decade because of extreme weather and wildfires. NOAA reported that the U.S. spent a record $306 billion to cover the cost of damage from 16 weather and climate disasters last year, each of which cost $1 billion or more.

Continuing to do nothing threatens our future. Retreating from rising seas, lost fisheries, droughts, hurricanes, bomb cyclones, pounding rain storms, ice storms, floods and ticks seems like a poor tradeoff to maintain a fossil-fuel-based economy from the last century.

We know how to do build cost-effective environmental policy based on science and succeed — we should do the same with greenhouse gases today.

Ivan Fernandez is a professor in the School of Forest Resources and Climate Change Institute at the University of Maine in Orono.

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