Associated Press File Photo / Nuclear energy, like that produced at Browns Ferry Nuclear Plant near Athens, Alabama, has helped TVA, and the city of Chattanooga in turn, reduce its overall carbon emissions.

Chattanooga, according to a newly released study, has cut its carbon emissions by more than 25% in the past decade.

It was not done through former President Barack Obama's Clean Power Plan, a constitutionally questionable proposal that the administration said would reduce carbon emissions but experts said the cost of which would hurt the poorest Americans most.

It was not done through the Paris climate agreement, which also was signed under the previous administration but which even its most avid supporters admitted would have little effect on the U.S.

The carbon reduction was achieved, according to the local environmental group green/spaces, which helped sponsor the study by Minnesota-based consulting firm paleBLUEdot LLC, through the drop in carbon emissions used for electricity and other energy and through the city reducing energy and wastes in its sewage treatment processes.

Carbon emissions from energy fell nearly 36% from 2008 to 2018, according to the study, largely because of Tennessee Valley Authority converting from coal to other sources to produce electricity.

Upgrades at the Moccasin Bend Wastewater Treatment Plant and improved storm water runoff facilities and practices were said to have cut greenhouse gases from wastewater more than 38% over the same period.

We have always believed that cleaner technologies should be brought online as long as their efficiency is supportable and their price tag is not exorbitant to ratepayers.

TVA, with a push from the Environmental Protection Agency, has done that, turning first to cleaner coal production and more recently to getting more of its energy from nuclear and natural gas.

Green energy zealots would have TVA using even more solar and wind power, but we feel that is unlikely to happen until the cost of those energy sources — without being subsidized by the federal government — comes down.

TVA, for instance, angered wind energy supporters in late 2017 when it said a 700-mile transmission line to bring wind energy from Texas and Oklahoma to Memphis did not make economic sense.

READ MORE: TVA's carbon cuts outpace most national utilities

However, the agency said earlier this year that during the first three months of 2020 it got more power from renewable sources than from burning coal. Further, the agency's president said it was on track to reach its goal of reducing carbon emissions 60% below peak 2005 levels in 2020 and 70% by 2023.

The same thing, we believe, will happen in the automotive industry when the price of electric vehicles, ease and accessibility in charging them and their driving range improve, or alternative energy sources for them are developed.

Indeed, we believe there's even a parallel between government and market-place economics in how wages are paid. In pre-coronavirus America, there was a hue and cry for minimum-wage hikes and minimum-wage laws for states and cities.

But research shows minimum-wage hikes often end up closing the establishments that cannot pay higher wages. The people who were supposed to be helped by the wage hikes then find themselves out of work.

No, as many corporations and businesses showed until the virus hit earlier this year, wages rise under high employment when there is a competition for the best workers and when companies want to keep the workers they have, and not through government intervention.

But on the automotive front, with Volkswagen's recent decision to make an $800 million investment in electric vehicles, Chattanooga will have a close-up view as transportation technologies evolve.

According to the paleBLUEdot study, though, transportation has become the city's biggest source of carbon emissions. And where carbon emissions are down more than 38% in wastewater and nearly 36% in energy, they are up 8.7% in transportation over the 2008-2018 time period.

It makes sense for cities to evaluate their energy use, and Chattanooga has done that by making upgrades in municipal buildings and parks and by Department of Energy initiatives that seek to reduce energy consumption in buildings.

The advances have been such that the city ranks lowest among Tennessee's four major cities in per capita release of greenhouse gases. And that's with the city having the highest share of manufacturing among the four, with its 44.8% growth in economic output and with its 14.3% population gain.

We believe the drop in pollutants is nothing short of amazing considering just over a half century ago it was rare to be able to see the city's downtown from Missionary Ridge because of its manufacturing-heavy filthy air.

People want cleaner air and water, but they understand achieving it will never be as as simple as putting your name on a global climate agreement or hurting the most vulnerable to achieve specific goals.