Among these young activists is the promoter of the "Friday for the Future" initiative, the Swedish teenager Greta Thunberg, who got thousands of European students to take to the streets every week to demand that their leaders move forward with change.
"Fantastic news from Ireland! Who's next?" Thunberg wrote in his Twitter account after hearing about the decision taken by the Irish Parliament.
"And remember: #ClimateEmergency means leaving fossil fuels on the ground," added the young activist.
The British Parliament declared May 1 "climate emergency", being the first country to do so.
The decision is symbolic and came after a growing number of climate rallies, with the UK government announcing that it would step up measures to tackle climate change.