Tokyo — This week the White House hosts a two-day Earth Day summit. Forty world leaders have been invited to the virtual event, during which Washington is expected to announce plans for further significant cuts in its carbon emissions.
But as an international organization warns that some nations' reliance on coal to power their economies back from pandemic lockdowns is driving the second-largest spike in carbon emissions ever, it will take more than one country's resolve to address the problem.
Staving off a climate catastrophe will depend on China, Japan and other major greenhouse-gas emitters dramatically reining in their reliance on fossil fuels, especially coal.
China "hanging on" to the past
China is the country that coal built. Its provinces have been compared to Appalachia, where coal is not just a cheap and plentiful fuel, but coal mining is a way of life.
"Coal has been part of many of these provinces' economies, but also part of the culture," Alvin Lin, climate and energy policy director at the National Resources Defense Council in Beijing, told CBS News. "Workers in these economies do closely identify with that."
By far the world's leading consumer of coal, China operates more than 1,000 coal-fired plants, and it continues to build new ones.
Despite China's dramatic advances in wind and solar energy and with electric cars, it faces the challenge of slashing its greenhouse gas emissions by almost half if it wants to meet commitments to limit global warming to the Paris climate accord target of 1.5 degrees Celsius.
"That's a huge task for any country, but especially for China, because of all the coal it uses," Lin said.
Eric Zusman, a senior policy researcher at the Institute for Global Environmental Studies in Hayama, Japan, said China's "schizophrenic patchwork of policies" on energy are a byproduct of the country's breakneck development.
"Contemporary China is a place where we see contradictions abound," he said. "You can walk down the street in Shanghai and see the latest AI, or the most advanced technologies, but not 200 yards away, people are still fixing bicycles with their hands."
Similarly, in the energy sector, Zusman says, "on one hand, you see a great deal of what we call leapfrogging — skipping over some of the stages of technological development — but you also see hanging on to the vestiges of the industrial engine that drove China for much of its early modern history."
Experts have expressed cautious optimism after last week's joint statement by the U.S. and China, pledging to work together to tackle climate change. Chinese President Xi Jinping may unveil new climate change pledges at an international forum this week in Hainan, but Chinese officials appeared to temper optimism this week.
"Some countries are asking China to achieve the goals earlier," Vice Foreign Minister Le Yucheng told The Associated Press this week. "I am afraid this is not very realistic."
"Risk" averse, Japan clings to coal
Resource-poor Japan is also a prime coal consumer. Coal supplies about a third of the country's electricity, and Japan is a major exporter of coal-fired plants to southeast Asia.
Japan's coal addiction stems in no small part from the, which forced the shutdown of most of Japan's reactors.
Kimiko Hirata, the international director for the Kiko Network, a nonprofit climate change organization based in Tokyo, says that abrupt shift in the energy supply has helped to make Japan the only major industrialized country still building new coal-fired power plants.
"Japan thinks oil has a risk," she said, referring to the 1970s "oil shocks" that left petroleum-dependent Japan panicking over spikes in energy prices. "And nuclear has a risk. That's why Japan still thinks that coal is an important energy source for Japan's electricity."
"Second biggest emissions rise in history"
Experts see the current moment as critical for tackling domestic inertia in various countries, by building a sustained global consensus on abandoning fossil fuels ahead of this November's United Nations Climate Change Summit in Glasgow. That is being billed as the most important event since the 2015 Paris agreement on limiting global warming.
But especially as the developed world helps its economies bounce back from the ravages of pandemic lockdowns, all nations have their work cut out for them.
Fatih Birol, executive director of the International Energy Agency and a global authority on energy production and the climate, told The Guardian this week that a heavy reliance on coal and other fossil fuels to power that rebound was driving the second largest surge in carbon emissions in recorded history.
"This is shocking and very disturbing. On the one hand, governments today are saying climate change is their priority. But on the other hand, we are seeing the second biggest emissions rise in history. It is really disappointing," she told the British newspaper.
"In 2021 global energy-related CO2 emissions are projected to rebound and grow by 4.8% as demand for coal, oil and gas rebounds with the economy," the IEA says in it's "Global Energy Review 2021" report, noting that it "would be the largest single increase since the carbon-intensive economic recovery from the global financial crisis more than a decade ago."
Scientists believe global carbon emissions will have to be cut by 45% within the 2020s if the Paris accords goal of limiting the rise in the average temperature to 1.5C can be met.
Given the dramatic spike in emissions this year, "our starting point is definitely not a good one," Birol told The Guardian.
Zusman told CBS News that, while he's optimistic a consensus will eventually settle around the need for a zero-carbon future, "I don't think it will be a linear path."
CBSNews.com's Tucker Reals contributed to this report.