The winnowing field of Democratic candidates for president deserve credit for trying to address the global climate crisis by dramatically reducing greenhouse emissions, including those from transportation, in sharp contrast to the actions of the Trump administration over the past three years.
We just wish that the candidates' proposals — many of which appear aimed at wooing left-wing primary voters — were more viable and effective.
Take, for example, latecomer Michael Bloomberg, who this month proposed essentially making it illegal to sell a new automobile with an internal-combustion engine after 2035 — just more than two product cycles from today. Instead, all new passenger automobiles by then must be electric, or otherwise produce no emissions.
We're all for lofty challenge goals, but this isn't a reasonable idea. The generation, transmission and charging infrastructures aren't prepared for a fleetwide conversion to electrified propulsion. And consumer demand for these vehicles — with relatively high costs and significant limitations — is far from universal.
There are more effective ways for the U.S. government to reduce transportation-related greenhouse gas emissions. One of the best would be federal incentives for trading in older, higher-polluting vehicles, including for used vehicles.
Bloomberg's all-electric proposal suggests subsidizing lower-income families' trade-ins, using a "Cash for Clunkers" type of system to spur sales of zero-emission vehicles. But even with thousands in assistance, low-income families can't afford a new electric vehicle.
But a newer used model? That's doable.
Consider this: Exchanging a six-cylinder automatic-transmission 2000 Toyota Camry for even a 2015 version would cut that driver's emissions by about 20 percent, and save 1.3 tons of greenhouse gas per year. The story's the same with most makes and models — the bigger the reduction in age, the bigger the reduction in emissions.
And boosting consumer demand for newer used vehicles will drive up residual values, ultimately making new, efficient — even electric — vehicles more affordable to middle-income and affluent consumers.
That would be a virtuous cycle everyone can get behind.