The main goal of the far right is to stop the green transition, Eamon Ryan told his party’s pre-election conference.
Speaking at the RDS in Dublin on Saturday, the Green party leader said an alternative politics based on fear and division is on the rise.
Mr Ryan warned that disinformation and polarisation are posing a risk to Irish democracy.
He said: “I wouldn’t define it as a right wing or conservative movement because it seems to have little regard for traditional values. Nihilism might be the better term. They seem to reject everything that is good with an anger that in the end will be corrosive and self-destructive.”
While thanking Integration Minister and Green party colleague Roderic O’Gorman for his work in providing emergency accommodation to people fleeing the war in Ukraine and others seeking international protection, Mr Ryan said: “The gospel I grew up with never said the Good Samaritan should have walked on by.
“Similarly, the patriots we admired, from Tone to O’Connell and Connolly to Pearse, all had an international perspective to their national pride.”
Noting that Mr O’Gorman’s house had recently been targeted by a protest involving masked men, he added: “I don’t think they would be at home with the simplistic idea that Ireland is now full. The Republic we adhere and aspire to is a tolerant one, respectful of every colour or creed, celebrating diversity and providing shelter to those in need.”
Mr Ryan also criticised a “politics of scepticism”, adding: “We have our weakness undoubtedly but Ireland is not a bad country to live in.”
The Green leader said his party could deliver more affordable homes by reducing prices through restoration of vacant and derelict homes, as well as improvement in water, transport and energy infrastructure.
In a speech which also addressed “great danger in the world” posed by war in Ukraine, Gaza and Sudan, Mr Ryan said democracy is at risk.
“Democracy is under threat in the United States where the prospect of another Donald Trump presidency looms large. Even in our European Union, the best suddenly seem to lack all conviction while the worst are full of passionate intensity.”
He said “a loss of faith in multilateral cooperation” has distracted people from the existential threat of climate change and the destruction of nature.
“We know that each of the last 10 months has been the warmest in recorded history. Average global air temperatures have gone above the 1.5 degree increase which scientists tell us is a tipping point, beyond which things could become unstoppable.
“In Ireland, we have seen the reality with endless rain over the last 10 months. Our fields are sodden, too wet to pick potatoes in the autumn or to sow grain in the spring. Cattle are still in their sheds.
“Around the world climate change is bringing havoc, causing conflict and forced migration. It is a sign of what is to come. ”
Mr Ryan said war had shifted focus from “bees to bullets”, warning that the European Council presidency’s draft strategy for the next five years effectively seeks to abandon the European Green Deal.
He said: “We cannot let this happen. We cannot give up on climate change. We cannot let our natural world collapse.
“We are at a critical point in history. If you believe that climate action cannot be delayed, then send a Green MEP to the European parliament.
“They may have the casting vote which tilts things back in the right direction. This is the key question in the European election. Will the far right whose main goal is to stop the green transition win the day? ”
The Green leader said ignoring the reality of climate change will ruin the security of future generations.
Mr Ryan said: “A vote for the Greens will improve the quality of life for all our people. The beauty of what we do is that it benefits both people and planet.
“It is a vote to protect our children’s future and send a message to the wider world that this island of ours is still going green. And we are good at going green in this country. ”
In particular, Mr Ryan said Ireland had halved its emissions per person over the previous two decades and that each month 1,000 additional households are experiencing warmer homes with lower fuel bills due to retrofitting grants.
He said the party had also scrapped VAT on solar panels and abolished the need to get planning permission before their installation.
