President Biden's Earth Day climate summit is a rebuke to Trump's denialism. But it's only a start.

America abandoned its position of leadership on climate change under Donald Trump, and it cost us. It cost us the very international standing he swore he so valued, and, more importantly, it cost us precious time to battle the climate crisis.

President Joe Biden and the entire U.S. government now have a pivotal opportunity to reclaim our leadership role on climate change and to do our part in reducing emissions. We must act now - and we must act big.

And there is no better time than Earth Day and no better opportunity than President Biden's Leaders Summit on Climate, which begins Thursday.

The first reason to act big is the math: We are the world's largest economy and must slash emissions rapidly to reach net-zero emissions by 2050. If we don't hit our emissions targets, we will fail to stay below the 1.5-degree C threshold of "safe" warming.

Second - and every bit as important - we need to act big to regain our international credibility. After four years of Donald Trump's preposterous climate change denialism and his administration's handouts to fossil fuel polluters, we must prove we as a country are truly serious about climate action. It is the foundation that is needed to again inspire ambition from others.

Rebuilding that foundation and that credibility won't be easy. The U.S. helped to establish the Paris Agreement system - from which Trump unilaterally withdrew just last year - of nationally determined contributions in which each country commits to emission reductions and enacts policies to guide their economies toward those goals. Those goals are meaningless without individual government action to implement them.

Many of our peers around the globe have risen to meet their commitments under the agreement. Canada enacted an ambitious carbon-pricing regime. The European Union committed to a 55 percent reduction in greenhouse gases by 2030, backed by investments in green technologies and a price on carbon emissions. Under a Conservative-led government, the United Kingdom committed to a 68 percent reduction by 2030, backed by investments in green technologies, a carbon price and a ban on the sale of internal combustion engine cars after 2030. And many other countries are also taking meaningful steps.

Some, however, have dallied. The world's top carbon emitter, China, eschewed leadership and forged ahead building coal-fired power plants, the most carbon pollution-intensive source of greenhouse gases. The world's fourth-largest carbon emitter, India, has dawdled, too: It is on track to increase its emissions by 2030.

And, of course, here in the United States, the Trump administration worked to roll back and undermine all kinds of regulatory protections on greenhouse gas emissions and ultimately pulled out of the Paris Agreement altogether.

As John Kerry, the special presidential envoy for climate, has said, "It's simple for the United States to rejoin [the Paris Agreement], but it's not so simple for the United States to regain its credibility."

So how does the country that turned its back on the very system we shepherded into being persuade other countries to follow our example?

The answer is clear: We must enact something big here at home - starting with President Biden's American Jobs Plan to "build back better." We must ensure the plan includes a comprehensive climate policy that produces measurable and meaningful emissions reductions. And we must pass it before the U.N. convenes its next Climate Change Conference of the Parties in Glasgow, Scotland, this November.

For all the talk of a broken Washington, this goal is within reach. President Biden and the Democrats in Congress already delivered big, bold legislation to address the pandemic and its economic fallout. Passing the American Jobs Plan is our best shot to put millions of Americans back to work, rebuild our infrastructure, restart our economy and tackle the climate crisis - which will be necessary to ensure America's future economic health, too.

The central components that need to be included in the bill are provisions to: prepare America's infrastructure for the climate change we know is coming; create incentives to speed the adoption of clean technologies and invest in manufacturing these technologies here at home; address climate effects along our coasts, where communities face some of the most pressing climate threats; make sure that our farms, forests and natural lands are net-sinks for carbon emissions; quickly and substantially increase research, development and demonstration to set the stage for future innovations and climate solutions; and make substantial investments. These investments will create millions of jobs and ensure a just transition for traditional energy communities. They will also remedy decades of environment harm in front-line communities and ensure a cleaner and more just future.

But even this is likely not enough, especially if we are to put our country on track to reach net-zero emissions by 2050.
To meet nature's test - the only test that matters - we also need to finally put a fair price on carbon pollution and implement a national clean electricity standard to steer us quickly toward a pollution-free future.

Confronting the climate crisis will require us to bring the whole world's scientific, political and economic powers to bear. But America has an important - and truly indispensable - role to play. By rejoining the Paris climate accord on his first day in office and calling for an "all-of-government" approach to climate, President Biden has signaled that he is serious about reasserting America's commitment to lead the world in climate action.

Congress needs to show him that he has our full support in doing so. When world leaders convene in Glasgow in November, President Biden needs to come armed not only with pledges and ambitious plans, but also a legislative track record that proves America's commitment to lead on this issue. He needs to be able to show that America is finally ready to make the substantial investments and implement the important carbon reduction policies necessary to move the needle on climate change for all of us.

As fathers, we know there is nothing more important than leaving our children and future generations a healthier planet. As three senators, we know the best chance we may ever have to make that happen is before us right now. And as leaders in a country that has, at our best, led the international community to accomplish great things by the power of our example, we know America's legacy hangs in the balance.

We must act now. And we must act big.