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This weekend marks two anniversaries that, for me, point a way forward through the accumulated wreckage of the past year.

The first is personal. Twenty years ago, I ended my presidential campaign after the Supreme Court abruptly decided the 2000 election. As the incumbent vice president, my duty then turned to presiding over the tallying of Electoral College votes in Congress to elect my opponent. This process will unfold again on Monday as the college’s electors ratify America’s choice of Joe Biden as the next president, ending a long and fraught campaign and reaffirming the continuity of our democracy.

The second anniversary is universal and hopeful. This weekend also marks the fifth anniversary of the adoption of the Paris Agreement. One of President Trump’s first orders of business nearly four years ago was to pull the United States out of the accord, signed by 194 other nations to reduce the emissions of greenhouse gases threatening the planet. With Mr. Trump heading for the exit, President-elect Biden plans to rejoin the agreement on his Inauguration Day, Jan. 20.

Now, with Mr. Biden about to take up residence in the White House, the United States has the chance to reclaim America’s leadership position in the world after four years in the back seat.

Mr. Biden’s challenges will be monumental. Most immediately, he assumes office in the midst of the chaos from the colossal failure to respond effectively to the coronavirus pandemic and the economic devastation that has resulted.

And though the pandemic fills our field of vision at the moment, it is only the most urgent of the multiple crises facing the country and planet, including 40 years of economic stagnation for middle-income families; hyper-inequality of incomes and wealth, with high levels of poverty; horrific structural racism; toxic partisanship; the impending collapse of nuclear arms control agreements; an epistemological crisis undermining the authority of knowledge; recklessly unprincipled behavior by social media companies; and, most dangerous of all, the climate crisis.

What lies before us is the opportunity to build a more just and equitable way of life for all humankind. This potential new beginning comes at a rare moment when it may be possible to break the stranglehold of the past over the future, when the trajectory of history might be altered by what we choose to do with a new vision.

With the coronavirus death toll rising rapidly, the battle against the pandemic is desperate, but it will be won. Yet we will still be in the midst of an even more life-threatening battle — to protect the Earth’s climate balance — with consequences measured not only in months and years, but also in centuries and millenniums. Winning will require us to re-establish our compact with nature and our place within the planet’s ecological systems, for the sake not only of civilization’s survival but also of the preservation of the rich web of biodiversity on which human life depends.

The daunting prospect of successfully confronting such large challenges at a time after bitter divisions were exposed and weaponized in the presidential campaign has caused many people to despair. Yet these problems, however profound, are all solvable.

Look at the pandemic. Despite the policy failures and human tragedies, at least one success now burns bright: Scientists have harnessed incredible breakthroughs in biotechnology to produce several vaccines in record time. With medical trials demonstrating their safety and efficacy, these new vaccines prefigure an end to the pandemic in the new year. This triumph alone should put an end to the concerted challenges to facts and science that have threatened to undermine reason as the basis for decision-making.

Similarly, even as the climate crisis rapidly worsens, scientists, engineers and business leaders are making use of stunning advances in technology to end the world’s dependence on fossil fuels far sooner than was hoped possible.

Mr. Biden will take office at a time when humankind faces the choice of life over death. Two years ago, the Intergovernmental Panel on Climate Change warned of severe consequences — coastal inundations and worsening droughts, among other catastrophes — if greenhouse gas emissions are not reduced by 45 percent from 2010 levels by 2030 and 100 percent by 2050.

Slowing the rapid warming of the planet will require a unified global effort. Mr. Biden can lead by strengthening the country’s commitment to reduce emissions under the Paris Agreement — something the country is poised to do thanks to the work of cities, states, businesses and investors, which have continued to make progress despite resistance from the Trump administration.

Solar energy is one example. The cost of solar panels has fallen 89 percent in the past decade, and the cost of wind turbines has dropped 59 percent. The International Energy Agency projects that 90 percent of all new electricity capacity worldwide in 2020 will be from clean energy — up from 80 percent in 2019, when total global investment in wind and solar was already more than three times as large as investments in gas and coal.

Over the next five years, the I.E.A. projects that clean energy will constitute 95 percent of all new power generation globally. The agency recently called solar power “the new king” in global energy markets and “the cheapest source of electricity in history.”

As renewable energy costs continue to drop, many utilities are speeding up the retirement of existing fossil fuel plants well before their projected lifetimes expire and replacing them with solar and wind, plus batteries. In a study this summer, the Rocky Mountain Institute, the Carbon Tracker Initiative and the Sierra Club reported that clean energy is now cheaper than 79 percent of U.S. coal plants and 39 percent of coal plants in the rest of the world — a number projected to increase rapidly. Other analyses show that clean energy combined with batteries is already cheaper than most new natural gas plants.

As a former oil minister in Saudi Arabia put it 20 years ago, “the Stone Age came to an end, not because we had a lack of stones, and the oil age will come to an end not because we have a lack of oil.” Many global investors have reached the same conclusion and are beginning to shift capital away from climate-destroying businesses to sustainable solutions. The pressure is no longer coming from only a small group of pioneers, endowments, family foundations and church-based pension funds; some of the world’s largest investment firms are now joining this movement, too, having belatedly recognized that fossil fuels have been extremely poor investments for a long while. Thirty asset managers overseeing $9 trillion announced on Friday an agreement to align their portfolios with net-zero emissions by 2050.

Exxon Mobil, long a major source of funding for grossly unethical climate denial propaganda, just wrote down the value of its fossil fuel reserves by as much as $20 billion, adding to the unbelievable $170 billion in oil and gas assets written down by the industry in just the first half of this year. Last year, a BP executive said that some of the company’s reserves “won’t see the light of day,” and this summer it committed to a 10-fold increase in low-carbon investments this decade as part of its commitment to net-zero emissions.

The world has finally begun to cross a political tipping point, too. Grass-roots climate activists, often led by young people of Greta Thunberg’s generation, are marching every week now (even virtually during the pandemic). In the United States, this movement crosses party lines. More than 50 college conservative and Republican organizations have petitioned the Republican National Committee to change its position on climate, lest the party lose younger voters.

Significantly, in just the past three months, several of the world’s most important political leaders have introduced important initiatives. Thanks to the leadership of Ursula von der Leyen, the president of the European Commission, the E.U. just announced that it will reduce greenhouse gas emissions by 55 percent in the next nine years. President Xi Jinping has pledged that China will achieve net-zero carbon emissions in 2060. Leaders in Japan and South Korea said a few weeks ago said that their countries will reach net-zero emissions in 2050.

Denmark, the E.U.’s largest producer of gas and oil, has announced a ban on further exploration for fossil fuels. Britain has pledged a 68 percent reduction by 2030, along with a ban on sales of vehicles equipped with only gasoline-powered internal-combustion engines.

The cost of batteries for electric vehicles has dropped by 89 percent over the past decade, and according to Bloomberg New Energy Finance, these vehicles will reach price parity with internal-combustion vehicles within two years in key segments of vehicle markets in the United States, Europe and Australia, followed quickly by China and much of the rest of the world. Sales of internal-combustion passenger vehicles worldwide peaked in 2017.

It is in this new global context that President-elect Biden has made the decarbonization of the U.S. electricity grid by 2035 a centerpiece of his economic plan. Coupled with an accelerated conversion to electric vehicles and an end to government subsidies for fossil fuels, among other initiatives, these efforts can help put the nation on a path toward net-zero emissions by 2050.

As the United States moves forward, it must put frontline communities — often poor, Black, brown or Indigenous — at the center of the climate agenda. They have suffered disproportionate harm from climate pollution. This is reinforced by recent evidence that air pollution from the burning of fossil fuels — to which these communities bear outsize exposure — makes them more vulnerable to Covid-19.

With millions of new jobs needed to recover from the economic ravages of the pandemic, sustainable businesses are among the best bets. A recent study in the Oxford Review of Economic Policy noted that investments in those enterprises result in three times as many new jobs as investments in fossil fuels. Between 2014 and 2019, solar jobs grew five times as fast in the United States as average job growth.

Still, all of these positive developments fall far short of the emissions reductions required. The climate crisis is getting worse faster than we are deploying solutions.

In November of next year, all of the signatories to the Paris Agreement will meet in Glasgow with a mandate to reduce greenhouse gas emissions much faster than they pledged to do in 2015. What will be new in Glasgow is transparency: By the time the delegates arrive, a new monitoring effort made possible by an array of advanced technologies will have precisely measured the emissions from every major source of greenhouse gases in the world, with most of that data updated every six hours.

With this radical transparency, a result of efforts of a broad coalition of corporations and nonprofits I helped to start called Climate Trace (for tracking real-time atmospheric carbon emissions), countries will have no place to hide when failing to meet their emissions commitments. This precision tracking will replace the erratic, self-reported and often inaccurate data on which past climate agreements were based.

Even then, a speedy phaseout of carbon pollution will require functional democracies. With the casting of a majority of the Electoral College votes on Monday for Mr. Biden, and then his inauguration, we will make a start in restoring America as the country best positioned to lead the world’s struggle to solve the climate crisis.

To do that, we need to deal forthrightly with our shortcomings instead of touting our strengths. That, and that alone, can position the United States to recover the respect of other nations and restore their confidence in America as a reliable partner in the great challenges humankind faces. As in the pandemic, knowledge will be our salvation, but to succeed, we must learn to work together, lest we perish together.

Al Gore shared the 2007 Nobel Peace Prize with the Intergovernmental Panel on Climate Change for his work to slow global warming.

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