While accepting a patron award for his work with Conservation International at the SAG-AFTRA Foundation’s Patron of the Artists Awards Thursday, famous Hollywood actor Harrison Ford attacked the “rise of nationalism and isolationism,” Variety reports.

Harrison argued that the “conservation community has made great progress,” but warned that “all that is under threat” because of politicians who don’t believe in climate change.

“The tested science on which our work is based is being challenged, being denigrated by those who want to protect the status quo and obviate the changes that everyone knows have to be made to sustain human life.”

Ford did not explicitly refer to U.S. President Donald Trump, nor did he mention any politician by name, but it is almost certain that the actor’s comments were made in reference to Trump’s isolationist policies and stances toward climate change. On multiple occasions, according to the Guardian, Donald Trump denied climate change, arguing that scientists have political agendas, and questioned the validity of their claims. In a 2012 Twitter post, Trump argued that the concept of global warming had been “created by and for the Chinese” in an effort to make American manufacturing “non-competitive.”

The POTUS seems to have change his mind, at least to an extent, since he recently remarked that climate change is actually not a hoax, but added that he is unsure about it being man-made. But Donald Trump is not the only politician to openly deny climate change.

Brazil’s president-elect Jair Bolsonaro is a far greater threat than Trump, according to the Yale School of Forestry & Environmental Studies, since the far-right proponent of military dictatorship has vowed to open the lungs of the planet, Amazon, to widespread development.

With the ascension of Jair Bolsonaro, Brazil is facing an “Apocalypse Now” moment for the Amazon. The president-elect has vowed to end environmental licensing for infrastructure projects & ban the creation of new protected areas or indigenous territories. https://t.co/zwuc8uY2l8 — Yale Environment 360 (@YaleE360) November 8, 2018

According to Yale, Jair Bolsonaro’s climate change denial — in combination with his complete control of Brazil’s centralized government — means that he will likely do unprecedented damage to the Amazon, as well as the international effort to soften the blow of climate change. With Bolsonaro in power, the deforestation rate in the world’s largest rainforest is likely to triple, and the damage he is likely to do could be irreversible, according to Yale.

Even though the humanity seems to be facing a monumental and existential threat, actor Harrison Ford remains hopeful. During the acceptance speech, Ford said that young people around the globe are committed to saving the planet. “They’re curious, they’re innovative, they’re more educated than ever before, they’re demanding solutions. They’re going for it. They’re all in. That gives me hope,” Harrison Ford concluded.