Former US President Obama addressed a crowd Monday at the 2021 United Nations Climate Change Conference in Scotland, slamming former President Donald Trump for decisions he made regarding climate change.

Iran PressAmerica: “Some of our progress stalled when my successor decided to unilaterally pull out of the Paris Agreement in his first year in office,” said Obama.

Obama expressed regret that Trump’s tenure resulted in “four years of active hostility towards climate science.” He noted that while the Republican Party, in general, has largely denied climate change, more needs to be done by many other governments to battle the threat.

“I recognize that we’re living in a moment when international cooperation has atrophied — in part because of the pandemic, in part because of the rise of nationalism and tribal impulses around the world, in part because of a lack of leadership on America’s part for four years on a host of multilateral issues,” Obama said in a speech while attending Day Nine of the COP26 at SEC Centre in Glasgow, which ends on Friday.

US President Joe Biden appeared at the conference earlier last week, where he too apologized for his predecessor’s actions and attempted to assure world leaders that America is “serious” about climate change.

Obama lambasted those who would play politics to avoid acting on climate change, calling out Russia and China in the same breath as Republican politicians back home.

“I guess I shouldn’t apologize, but I do apologize for the fact that the United States — the last administration — pulled out of the Paris Accords and put us sort of behind the 8-ball,” Biden said last week.

Obama, under whom Biden served as vice president for two terms, reiterated Trump’s failures on climate change, adding, “Of course, back in the United States, some of our progress stalled when my successor decided to unilaterally pull out of the Paris Agreement in his first year in office. I wasn’t real happy about that.”

“And now with President Biden and his administration rejoining the agreement,” Obama continued, “the US government is once again engaged and prepared to take a leadership role.”

He noted that many of the countries that stayed in the Paris Agreement have still not met the goals the accord set, which included holding the increase in the global average temperature to well below 2 °C, and pursuing efforts to limit the temperature increase to 1.5 °C, recognizing that this would significantly reduce the risks and impacts of climate change.

“As I’m sure is true for all of you, there are times when I feel discouraged when the future seems bleak, and I am doubtful that humanity can get its act together before it’s too late,” Obama said of the threat of climate change “and images of dystopia start creeping into my dreams. And yet, whenever I feel such despondency, I remind myself that cynicism is the recourse of cowards. We can’t afford hopelessness.”

He noted that younger attendees of the conference are “right to be frustrated.”

He encouraged them to vote and continue to raise awareness of the issue.