Determined to lead the charge against climate change, the U.S. and China have embarked on a fresh round of meetings aimed at setting their carbon emission targets ahead of next year's all important climate talks.
Renewed commitment by the world's two largest emitters, have stoked hopes for a strong accord when governments gather in Paris next December to forge a new global treaty to prevent the catastrophic warming of our planet.
According to some observers, the U.S.-China relationship is the most promising development in nearly two decades of climate talks. Together, their combined emissions match nearly the rest of the world's put together.
These latest round of negotiations come two months after the two powerhouses pledged to lead the charge against global warming.
In the past, lack of cooperation between Beijing and Washington has sabotaged climate talks, including a much hoped for deal in Copenhagen five years ago.
"We should be confident that the Paris meeting will not be another Copenhagen," says China's chief climate negotiator Xie Zhenhua. Toxic air pollution across the world's most populous nation has forced the government to clean up its act.
Xie's comments came a few days after Beijing passed the first amendments to its environmental protection laws in a quarter of a century.
Coming into effect at the beginning of next year, the new mandate will mete out harsher punishment for polluters, and greater power for environmental regulators. It will also allow authorities to detain company CEOs for 15 days if they fail to comply with the new standards.
The move came seven weeks after premier Li Keqiang declared a "war against pollution". Earlier this year, much of northern China became cloaked in a thick apocalyptic smog many scientists to likened to a nuclear winter.
Linked to a shorter life expectancy of around five years, the noxious air sparked a huge public outcry, especially in Beijing, where people vented their frustration with the government through the Chinese version of twitter.
Although much of the smog comes from cars, it also drifts in from coal-fired power stations which provide electricity for two thirds of the country. Abundant and cheap, coal has helped China to become the world's largest workshop, and second biggest economy.
After sacrificing the environment for decades to achieve breakneck economic growth, China is now making its fight against pollution one of the cornerstones of its current ten year plan.
The stability-obsessed government appreciates how failure to act, in a country of 1.3 billion people, will mark its great undoing. Things will become particularly challenging once the ravaging effects of climate change start to ripple across the continent.
According to the head of the World Bank Jim Yong Kim, warming temperatures will usher in conflicts over food and water within the next 5 to 10 years: "There's just no question about it."
Last month, in a paper submitted to the United Nations, China urged all developed nations, "without any conditionality," to raise their emission targets above current levels
The paper was sent as the UN released its most sobering assessment on the state of our climate yet: "Things are worse than we had predicted. We are going to see more impacts, faster and sooner than we had anticipated," said Saleemul Huq from the Independent University in Bangladesh.
"Nobody on this planet is going to be untouched," warned Rajendra Pachauri, the head of the group's Intergovernmental Panel on Climate Change.
That brutal assessment came six months after the Nobel Peace prize winning body revealed that our planet is warming much faster than expected: temperatures may now breach the upper safe limit of warming within the next thirty years.
Last week, the EU's top climate commissioner Connie Hedegaard called on China to set the pace in global climate talks.
Impressed by the country's efforts to rein in pollution at the local level, Hedegaard urged Beijing to adopt the same approach to UN negotiations: "I would hope that this domestic strong focus can be translated into a strong position internationally, because that would be a game changer."
By 2020, China has pledged to cut its emissions per unit of GDP by at least 40 percent from 2005 levels.
And, to meet that target, China has plowed billions of dollars into renewable energy, and energy efficiency projects. In fact, it's now the world leader in the clean energy race. And, solar, wind and hydropower account for nearly a third of the country's electricity capacity.
But, in spite of these efforts, Beijing does not want to make its ambitions internationally binding.
Although China is the world's second largest economy, 100 million of its people still live in chronic poverty, living on less than $400 a year.
And, other major emitters such as the U.S., Japan and Canada will not accept binding targets unless China does too. Negotiations in the past have failed as developed and developing nations squared off over who should make the bulk of cuts.
According to developing countries, rich nations should embrace that responsibility as they caused the climate crisis by industrializing a century and a half ago.
But, developed economies argue that poor nations must bear some of the burden as coal-fired economies in China and India create a large proportion of today's emissions.
In fact, emissions have risen at a record pace over the last decade, in large part due to China.
"We believe that countries should be expected to act in a differentiated way, fully taking into account their varying national circumstances and capabilities," says U.S. climate envoy Todd Stern.
Given that China is now the world's largest polluter with a severe domestic smog crisis that threatens its stability, it will be interesting to see how it proceeds forward in this era of grave global warming. Although its top climate negotiator says that Beijing will certainly act, the more pressing question is, will it be enough?
A clearer picture will emerge as the U.S. and China continue with their latest round of talks, and once heads of states gather in New York this September to hammer out a blue print for next year's Paris treaty.
With a steep temperature rise sitting on our collective horizon, one can't help but wonder how long humanity will have to wait before it gets climate justice. As Martin Luther King once said: "Not long, because no lie can live forever... Not long, because the arc of the moral universe is long, but it bends toward justice."