The Economist, no radical rag, wrote in 2011 that, looking back 100 years from now, the only important question about our current historical moment will be "whether or not we did anything to arrest climate change".
But you would not know it from the prevailing political discourse in the US. Climate change remains the great unmentionable on Capitol Hill and the campaign trail, and the mainstream media is doing precious little to call politicians out over their shameful silence.
In his acceptance speech at the Republican party's National Convention in August, Mitt Romney mocked the very idea of caring about climate change. "Four years ago, President Obama promised to begin slowing the rise of the oceans," Romney said, as the party faithful chortled. "And heal the planet," he added to further laughter.
"My promise is to help you and your family." Romney's words, and the crowd's delight, demonstrated again how extreme today's Republican party has become. Even former president George W Bush, for all his resistance to tackling climate change, never made fun of it.
Romney's mockery did have one positive effect: It led Obama to utter the "C-word" himself, something he has rarely done recently.
Environmentalists were delighted when Obama said in his acceptance speech at the Democratic Party's National Convention: "Yes, my [energy] plan will continue to reduce the carbon pollution that is heating our planet, because climate change is not a hoax. More droughts and floods and wildfires are not a joke. They are a threat to our children's future."
But was Obama merely punching back at Romney and telling the Democratic base what they wanted to hear? After all, as in most of his campaign appearances this year, Obama's acceptance speech mainly addressed his energy strategy, which calls for exploiting all available energy sources, including oil, gas and what he (inaccurately) calls "clean coal".
Spell of extreme weather
In an interview in April, Obama told Rolling Stone magazine that he expected climate change to be an issue in the presidential campaign, and he promised to "be very clear in voicing my belief that we're going to have to take further steps to deal with climate change in a serious way". Except he didn't.
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It was not for lack of opportunity.
Over the last six months, the US has suffered one of the hottest summers and worst droughts in its history, sparking wildfires, stunting crops and costing the American economy billions of dollars.
Meanwhile, the Arctic ice cap has melted to its lowest level on record. The loss of Arctic ice is the "equivalent of about 20 years of additional carbon dioxide being added by man", Peter Wadhams, a professor of ocean physics at the University of Cambridge, told the BBC.
Throughout this spell of extreme weather, Obama remained silent, shunning the "C-word". Even as his own government's scientists affirmed climate change's connection to the extreme weather events of 2012, Obama declined to use his bully pulpit to make the link clear to the public, much less attempt to rally Americans to action.
Of course, with the sluggish economy and high unemployment, Obama has had a lot on his plate. But nothing else will matter if the planet becomes uninhabitable, and it is not hyperbole to say that this is the course humanity is on.
If current emissions trends continue, global temperatures will increase by six degrees Celsius by 2100, warns the International Energy Agency (IEA). "Even schoolchildren know this will have catastrophic implications," said Fatih Birol, the IEA's chief economist.
Nations threatened by climate change
Already, nearly 1,000 children a day are dying because of climate change, according to a newly published study. The annual death toll stands at 400,000 people worldwide.
Climate change is also costing the world economy $1.2tn a year, the equivalent of 1.6 per cent of economic output, reports the Climate Vulnerability Monitor, a study commissioned by 20 nations most threatened by climate change.
The report was released on the sidelines of the UN General Assembly meeting in New York in September. Most of the 400,000 deaths are "due to hunger and communicable diseases that affect above all children in developing countries", concluded the study, which was authored by 50 scientists and policy experts from around the world.
The good news is that the political terrain surrounding climate change may at last be shifting in the US. The conventional wisdom, apparently shared by Obama and his advisers, has assumed that talking about climate change turns voters off, because it is too dark, too controversial, too complicated.
"I think we have achieved a real tipping point with the public, in that they finally see for themselves what the reality of climate change means."
- Joe Romm, editor for Climate Progress
But a growing body of evidence challenges this view. Speaking out about climate change, and above all about how to fight it, can be a political winner, this argument goes, in part because the hellish summer of 2012 led many more Americans to think climate change is real and dangerous after all.
"I think we have achieved a real tipping point with the public, in that they finally see for themselves what the reality of climate change means," said Joe Romm, the editor of the nation's leading climate science blog, Climate Progress.
In his new book, Language Intelligence, he uses a baseball metaphor: "You can't say one individual home run was due to steroids, but when somebody gets 70 in one season, then you understand what it means for them to be juiced. Our climate has been juiced by the steroids of greenhouse gases, which make almost every major extreme weather event more extreme."
"Three out of four Americans now acknowledge climate disruption is real, and more than two out of three believe we should be doing something about it," declares Climate Solutions For A Stronger America, a new report intended to help activists, public officials and other advocates build public support for climate action (Disclosure: The report's sponsor and writer, Betsy Taylor, the head of the consulting firm Breakthrough Strategies and Solutions, is a friend of the writer). Climate Solutions For A Stronger America draws on numerous opinion polls, notably a new nationwide poll of 1,204 likely voters conducted specifically for the report.
Commissioned by Harstad Strategic Research, Inc, the polling group also carried out work for Obama when he was a senator and still does contract work for him as president. Among the polls' other findings was that "a pro-climate action position wins votes among Democrats and independents, and has little negative impact on Republican voters".
The narrative advocates can use to mobilise such voters, the report suggests, is the classic quest story: Heroes set off to vanquish villains in service of the common good. "Americans don't run away from big challenges," goes the script. "We turn them into big opportunities. We have a responsibility to our kids."
"But Big Oil and the Koch Brothers are standing in the way: Corrupting our political process and blocking American clean energy innovation. It's time to take our future back, and clean energy's a great way to do it."
In 2008, it looked as though Obama would be the hero to lead such a quest. But if four years of Obama's presidency demonstrate anything, it is the folly of waiting for any president to storm the barricades of entrenched power. If the US is to vanquish the climate villains and help win the quest for planetary survival, the people of America will have to be their own heroes.
Mark Hertsgaard is a Fellow of the New America Foundation in Washington, DC, and the environment correspondent for The Nation. He is the author of six books that have been translated into sixteen languages, including, most recently, HOT: Living Through the Next Fifty Years on Earth.
The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.