It was a moment Leonardo DiCaprio fans had been clamoring for for years: He finally won an Oscar, taking home the best actor award for The Revenant at the Academy Awards on Sunday night. DiCaprio's long-awaited acceptance could have been about anything, but he chose to focus on one of the most important scientific issues of our time: climate change.
Leo did his research. Almost every point he made can be proven by hard science. Here they are:
1. 2015 was the hottest year on record.
"Making The Revenant was about man's relationship to the natural world," DiCaprio said in his speech. "A world that we collectively felt in 2015 as the hottest year in recorded history."
He's right. Last year was the warmest since modern record-keeping began in 1880, according to NASA and the National Oceanic and Atmospheric Administration.
2. Snow in the Arctic has decreased over the past 50 years.
Climate change presented a challenge when filming The Revenant. "Our production needed to move to the southern tip of this planet just to be able to find snow," DiCaprio said in his acceptance speech.
It's true. Snow in the Arctic has decreased over the past 50 years, and snow is melting earlier than ever, according to NASA.
3. September sea ice is shrinking.
In fact, ice and glaciers everywhere have shrunk significantly in the last couple decades. The Arctic is especially at risk. September sea ice there has shrunk by about 12% every decade since the late 1970s, according to Weather Underground.
Of course, ice cover is part of a natural cycle. There will be rise and fall from year to year. Antarctica had a year of record sea ice cover in 2014, for example. But increasingly higher temperatures are bad news for ice cover everywhere in the long run.
"Higher surface temperatures will mean shorter duration of ice growth, thinner ice and therefore less extensive sea ice cover, including in the Antarctic region," said Joey Comiso, senior research scientist at the Cryospheric Sciences Laboratory, in a Q&A with NASA.
4. Sea levels and global temperatures are rising.
Global warming is an urgent threat. "Climate change is real. It is happening right now," DiCaprio said. "It is the most urgent threat facing our entire species, and we need to work collectively together and stop procrastinating."
Sea levels have risen 6.7 inches in the last century, global temperatures have risen since 1880 and the 10 warmest years have all happened in the past 12 years, the oceans have warmed about 0.3 degrees Fahrenheit since 1969, acidity of ocean waters has spiked 30% since the Industrial Revolution, and there have been more temperature extremes and intense rainfall since 1950.
5. Underprivileged nations will suffer first.
"We need to support leaders around the world who do not speak for the big polluters, but who speak for all of humanity, for the indigenous people of the world, for the billions and billions of underprivileged people out there who would be most affected by this," DiCaprio continued.
If we leave climate change unchecked, everyone is going to suffer. But the people who will suffer first are people in underprivileged communities who have done the least to fuel climate change. According to a United Nations report, poor areas in the warmer and drier areas of the world will be the first to see decreases in crop yields.
6. Natural disasters are increasing.
Climate change is also causing more extreme weather events like hurricanes, and those kinds of natural disasters hit areas in the tropics far more often than anywhere else.
If you're curious, here are the 32 most vulnerable countries, according to the risk analysis firm Maplecroft.
Here's DiCaprio's full acceptance speech:
DiCaprio wasn't the only Oscar winner who drew attention to climate change. When Jenny Beavan won the Oscar for best costume design in Mad Max: Fury Road, she made a startling comparison.
"I just want to say one quite serious thing, I've been thinking about this a lot, but actually it could be horribly prophetic, Mad Max, if we're not kinder to each other, and if we don't stop polluting our atmosphere," Beavan said. "So you know, it could happen."
If you've seen Mad Max: Fury Road, you know it takes place in a barren desert wasteland with almost no food and water. There's evidence to back up Beavan's warning that we're headed in that direction.
7. We're all at risk.
As DiCaprio pointed out, poor countries in warm areas are going to see crop yields plummet first. But according to Michael Oppenheimer, professor of geosciences and international affairs at Princeton University, once global temperature rise gets into the three- or four-degree range (we're hovering around a one-degree rise right now), even wealthy countries with advanced agriculture will suffer.
All this scientific evidence of climate change is probably a huge part of why Academy Award winners chose to use their acceptance speeches to pass on warnings and calls to action.