Today, we have again spent too long ignoring a looming crisis, one that threatens not just our nation, but the world. In 1863, the fate of the world’s only democracy was imperiled by the sin of slavery. Seven score and three years later, the fate of all the world’s people is imperiled by the poisoning of the climate. Over the course of two hundred years, hundreds of billions of tons of carbon have been dumped into our atmosphere, incurring a debt that is now being called for remittance.

Continuing on our fossil-fueled path, scientistKevin Anderson warns, will take us into a world that is “incompatible with organized global community.” Already, New Orleans and New York, Nashville and Minneapolis, Vermont and Kansas have faced unprecedented floods, fires, and storms, with lives lost and families torn asunder. The maelstrom is now upon us.

Once again, our politics are dominated by a wealthy elite, this time a ‘carbonocracy’ of fossil-fuel corporations. Their money is freely spent to corrupt our democracy; Obama’s inaugural ceremonies this year were brought to us in part by a $260,000 contribution by Exxon Mobil. The profits of these companies depend on their capacity to convince Americans, against all evidence, that climate change is not an urgent problem, that the expansion of offshore drilling, tar-sands pipelines, and natural-gas fracking are acceptable compromises, that the challenge of global warming can be put off for another generation.

If we do not change course now, and instead continue to increase the burning of coal and oil as multinational energy companies desire, we will fundamentally transform the very land we live on, the water we drink, the air we breathe in ways that are beyond our ken.

To defend Americans from the devastating impacts of climate change, Obama must recognize that the fossil-fueled economy is a moral wrong in our society that requires action today. “The path towards sustainable energy sources will be long and sometimes difficult,” Obama said on Monday. But if he aims to be our generation’s Abraham Lincoln, Obama must do what is hard. If Obama doesn’t present a plan on climate, one that severs our ties to a morally unfathomable economic system of planetary destruction, with the fixed idea that it must and will come to an end, the union will be lost.

Johnson is campaign manager of Forecast the Facts.