The White House is making a major diplomatic push to make sure this year's climate change talks in Paris are a success, and it scored two major victories Tuesday.

China, the world's largest emitter, formally submitted its long-awaited climate pledge, cementing its agreement to peak its emissions by 2030. The pledge builds on its agreement with the U.S. last year, with a plan to reduce its carbon intensity, or its emissions per unit of GDP, by up to 65 percent by 2030, compared to 2005 levels.

Meanwhile, the U.S. and Brazil unveiled a commitment in which Brazil committed to restoring a swath of forest roughly the size of Pennsylvania by 2030, while boosting its share of renewable energy. As part of bilateral talks between Brazilian President Dilma Rousseff and President Obama, Brazil also agreed to crack down on illegal deforestation in the Amazon rainforest, which acts as a carbon sink by absorbing carbon dioxide (reversing deforestation traditionally represents a bulk of Brazil's climate contribution).

As part of the agreement, the U.S. also would triple its share of non-hydropower renewable power by 2030,

Brazil's commitment did not represent a formal pledge, known as an Intended Nationally Determined Contribution, but it helps to form a backbone for such a document. But Tuesday's statements from the U.S., China, and Brazil—three of the world's top-10 emitters of greenhouse gases—represent major momentum just months ahead of the talks in Paris, where negotiators are hopeful that countries will produce a binding plan to slash global emissions.

With China on board and Brazil on the way, countries accounting for roughly 70 percent of the world's carbon emissions have made long-term climate pledges. Korea, Iceland, and Serbia also filed their INDCs on Tuesday, adding to a list that includes Canada, Mexico, and the European Union.

Speaking to reporters, White House climate adviser Brian Deese said that Obama has made the Paris talks a "central component" of each of his bilateral talks, representing the "degree of conviction and importance he puts on this issue."

Obama also has engaged in bilateral work with India, Mexico, and other major polluters in the past year. Just this month, Obama discussed climate change in a phone call with Korean President Park Geun-hye on June 11, weeks before the country unveiled a formal pledge that goes beyond a draft commitment. And he is expected to talk climate change with Pope Francis when the pontiff visits Washington in September.

The White House has promoted the climate talks as a legacy effort for Obama, but the country-by-country push also is necessary to shore up the president's climate plan at home. Critics have long said that the U.S. shouldn't be pursuing an intense domestic agenda when other countries aren't playing along, lest the U.S. lose its competitive advantage or suffer the economic consequences of a costly climate plan that will ultimately not offset other countries' pollution.

After days of energy talks with Chinese officials last week, State Department special envoy on climate change Todd Stern said the individual agreements send a signal to other governments as a "huge confidence builder" that no country will shoulder the burden of an international deal.

Senate Majority Leader Mitch McConnell even has called on countries to not buy into the U.N. talks given the potential legal challenges to Obama's climate plan, saying in a March statement that countries should "proceed with caution before entering into a binding, unattainable deal."

"For too long, those seeking to delay climate action have pointed a finger across the Pacific and said that the U.S. should not act until China does," said Lou Leonard, U.S. vice president of climate change for the World Wildlife Fund. "The commitments China outlined today essentially quash that overused and outdated argument."

China's formal submission isn't going to take that criticism away—opponents have said that China's pledge to cap emissions gives it too much leeway to drag its feet while the U.S. acts on its own. But Deese said that the diplomatic push on climate change through individual meetings will continue to produce policies that provide long-term stability and set the stage for climate action that will last for decades.

"We are continuing to have constructive conversations with China and other major emitters on how to make sure the framework has mechanisms in it "¦ so you don't have to go back to the drawing board and reinvent the wheel," Deese said. "There is a shared recognition that we have to have a mechanism and not just demonstrate transparently that these targets are met, but will increase in ambition over time."

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.