NEW GLOUCESTER — The potential for global warming from carbon dioxide emissions has been known in the scientific community since the early 1900s.

In the late 1950s, scientists were projecting that unless curtailed by 2000, carbon dioxide emissions would have potentially radical effects on climate.

In the late 1980s, George H.W. Bush came close to signing a global treaty to control carbon emissions, but backed down at the last minute at the behest of the fossil fuel lobby. Humanity and U.S. politicians in particular have kicked this can down the road for nearly 60 years, and local governments continue to do the same.

Our backs are now against the wall, with immediate action needed. In October, the U.N. Intergovernmental Panel on Climate Change warned that to prevent dramatic worldwide impacts, the world needs to reduce carbon emissions by 45 percent by 2030 and eliminate them by 2050.

Scientists increasingly fear that the West Antarctic Ice Shelf may collapse much sooner than previously thought. Unlike recently collapsed ice shelves, much of the ice is on land that will slide into the ocean, resulting in rapid sea-level rise projected to be 11 to 16 feet.

The California Coastal Commission, which oversees development along 1,100 miles of coastline, is revising its guidance to require planning for a 10-foot sea-level rise by 2100 (earlier guidance predicted a 6-foot rise). Unlike California, Maine does little to no sea-level-rise planning.

First and foremost, a global carbon tax is needed. Let the free market determine the most economical solutions. In the meantime, sensible planning can better position Maine’s economy for the coming dramatic challenges.

Recently, the Press Herald reported that in the next three years, four new developments are planned in Portland’s East End. Two of them – one, a fitness center-office complex; the other, a 105-room hotel and offices for Vets First Choice – plan parking garages totaling 940 spaces. Given that Vets First Choice and a third project – Wex‘s new headquarters – plan on a total of 1,900 employees at these sites, building 2,000 spaces seems more appropriate. At the going construction cost of $20,000 per space, $40 million is required for parking garages.

The new buildings are expected to generate four times as much traffic as the current properties. Nearly all this traffic will be on Franklin Street, which is already a mess at Marginal Way and Interstate 295.

Meanwhile, to alleviate a few hours’ congestion a day, the Maine Turnpike Authority this fall approved spending up to $160 million to widen 5 miles of the highway between Scarborough and Westbrook. Widening does not address the secondary congestion that daily backs up on to the turnpike. This money could be much better spent on regional mass transit systems than on a six-lane highway that by necessity will soon be obsolete. The authority was supposed to cease operations in the early 1980s, when the original construction bonds were paid. It’s long past due for the authority to be absorbed by the Maine Department of Transportation and become responsible to our elected representatives.

The money spent on turnpike widening, parking garages and secondary roads would be much better invested in regional commuter rail. The state owns the unused line from India Street to Lewiston, via Falmouth and Yarmouth. In Yarmouth, this line crosses the lightly used Downeaster tracks to Brunswick. From Brunswick, the state owns essentially unused lines to Lewiston, Augusta and Rockland. Commuter rail from Bath to India Street would reduce traffic on I-295, which is more congested than the 5-mile turnpike section.

Similarly, the state owns the unused rail line from the Portland Transportation Center to Fryeburg. This line passes through Westbrook, South Windham, Sebago Lake village and Steep Falls in North Standish. If this were revitalized, it could greatly reduce commuter traffic in Gorham (Route 25) and Westbrook (Brighton Avenue).

There needs to be a holistic regional transportation plan that improves mass transit and takes advantage of the region’s rail assets to better position the Maine economy for a carbon tax. The alternative is economic and social catastrophe with Fore Street and the Back Cove trail underwater.