With former Vice President Joe Biden leading in the polls and Democratic control of the Senate possible, the United States may soon have the chance, for the first time in more than a decade, to enact urgently needed legislation to address global climate change—but only if Democrats don’t repeat the mistakes they made at the start of the Obama administration.

In June 2009, the House of Representatives narrowly passed the American Clean Energy and Security Act, a comprehensive bill to stave off the worst effects of climate change. The landmark legislation died in the United States Senate, however, even though President Barack Obama supported climate action and Democrats controlled the Senate with a filibuster-proof majority. Other major issues took precedence: securing a stimulus package to address the recession, passing the Affordable Care Act, and enacting the Dodd-Frank financial reform and consumer-protection law.

As a result, the United States scuttled its best chance to prevent the havoc of climate disruption. In the ensuing decade, the world hurtled at breakneck speed toward the precipice of climate disaster. The most optimistic scenario now is that we have only a decade left during which we can limit—not prevent—the economic calamity and public-health nightmare that climate disruption will visit upon our children and grandchildren; the worst-case scenario is that we have already passed the tipping point on climate.

Whether we have any chance of avoiding catastrophic climate disruption will be decided this November. The Trump administration rolled back nearly every climate action taken by Obama and will double down on those policies in a second term. The United States will withdraw from the Paris Agreement the day after the November election and will reenter the agreement and pursue urgent climate action only if Biden wins in November.

If the fate of American democracy is on the ballot in November, so too is the future of the planet. It is one more way that the stakes could not be higher in this election.

Yet with a pandemic raging, the economy cratering, and systemic racism finally receiving the attention it deserves, there is considerable risk that a Biden administration and its allies in Congress will follow the lead of the Obama administration and prioritize other pressing issues over the need for climate action. If climate action is not a top priority—and one that results in new laws that commit the United States to decarbonization of its economy and allow it to provide global leadership on climate action—no other accomplishment will matter in the long run.

At this point, the public is so familiar with the acceleration of climate change that it may dismiss the dire warnings as dreary weather reports. The facts bear repeating.

The past five years have been the hottest on record; 19 of the hottest 20 years have occurred since 2001. Polar ice and glaciers are melting. Coral reefs and rainforests are disappearing. Hurricane season comes earlier and more intensely, and every year brings 100-year storms.

If we fail to limit greenhouse-gas emissions by 2030, searing heat, widespread drought, destructive storms, and coastal flooding will become even more common. Rising oceans will envelop coastal cities such as Miami, New York, Boston, New Orleans, and Houston. The Pentagon predicts that mass migration and climate refugees will lead to widespread political instability.

Avoiding this fate should be reason enough for the United States to take decisive action on climate early in a Biden administration. Climate action also will have a significant effect on the frequency of future pandemics and the stability of the economy—and Americans who are Black, Indigenous, and people of color will suffer the worst consequences as climate disruption exacerbates existing economic inequality and magnifies health disparities that plague poorer communities.

Biden appears to understand: He has made clean-energy investment a central plank of his "Build Back Better" platform. His ambitious proposals, if enacted by Congress, would substantially reduce greenhouse-gas emissions in the United States over the next decade and put the country on track to achieve carbon neutrality by 2050, goals the country must reach to limit climate change.

President Obama also understood the urgency of climate change, particularly during his second term, when he made climate action more of a priority and imposed regulatory limits on carbon pollution. Even so, he got nowhere with Congress. How can a Biden administration keep history from repeating itself if a Democratic administration once again comes to power during an economic crisis?

Perhaps the answer lies in a different historical precedent, that of the late 1960s and early ’70s, when the American environmental movement enjoyed its greatest success. Then as now, controversial issues divided the country, including civil rights for Black Americans, equal rights for women, and the war in Vietnam. Those conflicts spilled into the streets, before and after the death of Martin Luther King Jr., igniting riots in Detroit, Los Angeles, and Washington, D.C. Americans worried about an imperial presidency, adherence to the rule of law, and threats to democratic norms. President Richard M. Nixon resigned before Congress impeached him, but he had maintained an enemies list, railed against the media, and weaponized law enforcement against peaceful protesters.

In a United States roiled by far-reaching social change and turmoil, a desire for consensus and reconciliation emerged, fueling a remarkably bipartisan environmental movement. Protecting the Earth from pollution became an issue about which Americans from all backgrounds could agree. Transformative change ensued, altering industrial practices and waste management nationwide.

In the waning days of the Trump administration, amid carnage far greater than the dystopian fantasies peddled by President Donald J. Trump during his inauguration, most Americans want to move beyond divisiveness, partisanship, and the sense that the country cannot come together on issues that matter.

With effective leadership from the White House, climate action could be an issue in which the country finds a united purpose, as environmental and labor groups have already. Even in the midst of the pandemic, public opinion has shifted dramatically about the need for climate action: Two-thirds of all Americans recognize the need for climate action. States, cities, and towns across the U.S. are pursuing bold climate-mitigation and resiliency programs.

Major corporations such as Google, Microsoft, and Walmart devote significant resources to sustainability programs, and more than 100 companies now have internal carbon-pricing policies. The Business Roundtable made the commitment last year to "protect the environment by embracing sustainable practices across our businesses." Market forces are driving the United States toward a clean-energy economy, as wind and solar energy rapidly expand and become less expensive than traditional fossil fuels.

Moreover, the transition to a carbon-free economy will require major infrastructure investment that aligns well with the fiscal policies that most economists advocate to address the economic fallout from the pandemic—and the disproportionate effect of climate change on poor communities and people of color should make climate action a priority for Americans committed to ending systemic racism.

This can be an inflection point in American history, when the country takes dramatic steps to address climate change and protect the health and economic security of all Americans. If we fail to do so, the extraordinary crises of today will seem small by comparison.