Secretary of State John F. Kerry introduces actor and environmental activist Leonardo DiCaprio during the Our Oceans conference last month in Washington. (Chip Somodevilla/Getty Images)

While actor Leonardo DiCaprio will generate plenty of buzz when he speaks with President Obama and atmospheric scientist Katharine Hayhoe on the South Lawn on Monday night, it’s worth noting that this is not the first time the Oscar winner has interviewed an American president about the state of the climate.

It’s just that this time, the climate is in much, much worse shape.

DiCaprio sat down with Bill Clinton in the White House in March 2000, when he was in town to host a celebration of the 30th anniversary of Earth Day. During that event, DiCaprio asked Clinton why the issue of global warming was “so constantly overlooked,” and whether he would rank it as important as health care and education.

“Oh yes, over the long run, it’s one of the two or three major issues facing the world over the next 30 years,” Clinton replied. “I think it’s because it takes a long time for the climate to change in a way that people feel it, and because it seems sort of abstract now.”

While Clinton took pains to detail some of the evidence, noting at the time that nine of the 11 “warmest years on record have occurred in the last decade,” most of the impacts he described would occur in the future.

“So, the climate is changing, and the globe is warming at an unsustainable rate,” the president said. “And if it is not slowed and ultimately reversed, what will happen is, the polar ice caps will melt more rapidly; sea levels will rise; you will have the danger of flooding in places like the precious Florida Everglades or the sugar cane fields of Louisiana; island nations could literally be buried.”

DiCaprio, who stars in and produced the new National Geographic film on climate change, “Before the Flood,” will talk with Obama as part of the White House’s South by South Lawn festival.

Now, Obama could cite nearly the same statistic as the 42nd president: nine of the 10 hottest years on record have occurred in the past decade. But 1998, which held the record back in 2000, is in seventh place, and it’s sure to slip to eighth once the numbers for 2016 are finalized.

Atmospheric concentrations of carbon dioxide were 368 parts per million when DiCaprio and Clinton chatted; they are now above 402 ppm. The average area of sea ice atop the Arctic Ocean in May was just 12 million square kilometers (4.63 million square miles), according to the National Snow and Ice Data Center (NSIDC). That’s nearly 1 million square kilometers less than what it was back in 2000.

And as these signs of climate change have accelerated, so have the alarm signals from both scientists and policymakers. The Intergovernmental Panel on Climate Change issued a report in 2001 concluding that human-generated greenhouse gas emissions were “likely” — meaning there was a 67 percent to 90 percent chance — to have caused at least half of the Earth’s total temperature rise since the mid-1950s. In its most recent 2014 report, the IPCC said this was “extremely likely,” meaning there was at least a 95 percent chance human activity was responsible.

The international pact governing greenhouse gas emissions a 15 years ago was the Kyoto Protocol: It only covered industrialized countries. On top of that, the United States failed to ratify it, and Japan and Canada eventually opted out of fulfilling their commitments.

By contrast, nearly 200 countries signed off last year on the Paris Accord, which commits developing and developed nations to making carbon cuts in the years ahead. And global renewable energy capacity has increased 120 percent since 2000, though it remains a small fraction of the world’s energy supply.

Enric Sala, a National Geographic explorer-in-residence who journeyed to the Arctic with DiCaprio, said the movie was less about convincing people that climate change is real — a major objective of the 2006 documentary with Al Gore, “An Inconvenient Truth”— than by galvanizing them into action.

“We are at a different point in time. We are not debating whether climate change is real,” Sala said. “Now we are looking at solutions. We have to implement the solutions now. We cannot wait any longer.”

Fisher Stevens, the movie’s director, said that “Before the Flood” is “more of a journey, with a guy going around trying to figure something out.” DiCaprio plays the Everyman role, talking to scientists and other experts in far-flung places where climate effects are starting to change people’s way of life.

Stevens noted that he doesn’t “have any real delusions of grandeur.” Still, he added that he does hope the film could affect the way Americans and others think about climate change, whether it includes voting for certain candidates or curbing their use of palm oil, which has led to massive deforestation.

“I know it’s just a little documentary,” he said. “But I’m hoping it inspires some people to do something.”

The next stop for DiCaprio and Stevens will be Tuesday at the University of Miami, where they plan to talk about how Florida’s Sen. Marco Rubio and Gov. Rick Scott, both Republicans, questioned connections between human activity and climate change.

“And yet that state is one of the most vulnerable states to climate change in the U.S.,” Stevens said.

While the film highlights multiple steps individuals can take to address climate change–including paying a voluntary carbon tax to offset one’s emissions, which the filmmakers did for “Before the Flood”–neither DiiCaprio nor Obama can boast light carbon footprints. The president travels with an extensive entourage wherever he goes: his trips often include multiple armored  cars and helicopter flights  in a single day. DiCaprio, who has held fundraisers for his foundation in St. Tropez and frequently visits exotic locales, alludes to this issue in the film in a scene where he’s driving a hybrid.

Stevens noted that the crew and DiCaprio were struck during the making of the film by the fact that eating meat and dairy translates into higher greenhouse gases–given the enormous resources cattle consume and the methane they emit–along with the link between palm oil plantations and deforestation. As a result, he said, all of them shifted what they eat.

“The entire crew have massively changed their diet,” he said. “Leo’s diet has changed pretty drastically.”