In 2008, Republican presidential candidate John McCain vowed to lead on climate change and said: "We stand warned by serious and credible scientists across the world that time is short and the dangers are great."
At that time, there was bipartisan support for a market-based approach to curbing emissions that are heating up the atmosphere and oceans.
In 2005, then-Massachusetts governor Mitt Romney signed onto a cap-and-trade pact among Northeastern states to reduce greenhouse gas emissions.
Top Republicans were among those who saw economic benefits in the technological retooling that would be required to combat climate change.
So what happened?
Denying climate change became a political litmus test for Republicans, Democrats took a dive on the issue and it has all but disappeared from the political radar.
Weather has joined politics and religion as topics you don't bring up in polite company without risking an ideological firefight. What had been a thoughtful bipartisan discussion has fractured along the all too familiar political divide.
Meanwhile, we're experiencing — at a high cost in dollars and lives — the extreme weather that climate scientists predicted. (Scientists are loathe to pin any one weather event to human-made changes in climate but say the trend of extreme and violent weather is a preview of what global warming will bring.)
Against this desultory backdrop, it's encouraging to see the University of Kentucky scientists whose commentary appears on the facing page inject some cool clarity into the discussion.
The UK academics even shoulder some of the blame, saying if those who accept mainstream science had been better teachers, more respectful and understanding toward those with different perspectives, the issue would not have become so polarized.
They may have a point.
But the origins of the backlash are more complicated and calculated than that.
The funding to spread disinformation about climate science comes from polluting industries that don't want new emissions limits. In many cases they are the same interests that bankroll politicians who bash climate science as an elitist vendetta against coal miners and people who like big cars.
Visionary leaders take a more enlightened view. You'd expect Microsoft to be trimming its carbon footprint. But Duke Energy? Among the electrical utility giant's aspirations is to "decarbonize" its power generation. Rio Tinto, one of the world's largest mining companies, supports action against climate change. This is not tree-hugging do-goodism; it's a rational response to the massive economic disruptions that failure to act will wreak.
Just last year a famous physicist who was also a global warming skeptic analyzed all the data and concluded the climate scientists were right and that most of the pronounced warming of the last 50 years is human made.
As the UK scientists say, we've got to find a way to talk about this.
In 2008, both presidential candidates agreed on climate change and the need for action.
The great divide that has opened since then — and the yawning silence in Congress — may be just politics. But they also imperil the planet.