The two-week COP26 conference brought together 120 state leaders expected to agree new initiatives on reducing greenhouse gas emissions and slowing down the temperature increase.
"This must become one of our main political topics," Plenković said, adding that Croatia "is not a problem" because it has the fourth lowest harmful gas emissions per capita in Europe.
"The problem are the big countries whose industry, traffic and agriculture contribute a lot to carbon dioxide emissions," said Plenković, who will address the conference on Tuesday.
He said he saw the conference as a way to raise awareness of climate change, notably among the young population which "deserves a future" such as the one older generations had.
Plenković said the current political generation had the responsibility to make a step forward when it came to climate change and that the leaders who came to Glasgow were aware of the climate emergency.
"It's something that's here, before us," he said, adding that politicians "didn't come to walk around Glasgow but to make a contribution."
He said it was "a pity" that representatives of China and Russia were not present, adding that "they have their policies" on attending international conferences in times of COVID-19.
On the fringes of the conference, Plenković met with Indian Prime Minister Narendra Modi, Ukrainian President Volodymyr Zelensky, Polish Prime Minister Mateusz Morawiecki, and Dutch Prime Minister Mark Rutte.