The country's largest university has announced a deal for students who miss classes to attend today's climate strikes.
In the deal stuck between authorities at University College Dublin and the Students Union, students will not be penalised for skipping classes where marks are normally awarded for attendance.
The move follows a decision by University College Cork to actively encourage its staff and students to support the strikes.
UCD Students Union president Joanna Siewierska said she was delighted.
"Some staff are rescheduling classes so students don't miss out and it's great to have that kind of solidarity on such an important issue."
Third-level strikers will join thousands of secondary and primary school pupils at lunchtime protests in at least 20 cities and towns today as well as more than 60 solidarity events in workplaces and community settings.
Trade unions, more than 30 NGOs affiliated to the Stop Climate Chaos coalition, academics and political groups are all backing the strikes.
Mira Henchi, a student in Cork Educate Together Secondary School, and a member of the Schools Climate Action Network, said the strikes needed the broader support of society at large.
"This crisis is an intergenerational issue. We're all in this together, young and old," she said.
Teachers bodies have also expressed support for the strike although one school, Blackrock College in Dublin, has drawn criticism after principal Alan MacGinty, in a letter to parents, said the strikes are "infuriating". Calls to Mr MacGinty were not returned.
Climate Action Minister Richard Bruton, who travels to New York today to take part in the United Nations Climate Summit, praised the young activists behind the protests.
"Young people have led the way with highlighting the urgency of taking climate action. It is important that decision-makers listen and take note of their experience. I have heard the voices of those protesting today," he said.
Catholic bishops will also march, saying they applauded the students' leadership in protecting the environment.