The list of lawyers, scientists and environmental experts voicing concern over the new Climate Bill continues to grow as scrutiny of the draft legislation enters its final days.
Prof Barry McMullin of DCU is the latest to speak out, urging a rewrite that could replace the goal of being carbon neutral by 2050 with an even tougher target.
He is among the experts invited to make written submissions to the Joint Oireachtas Committee on Climate Action (JOCCA) which has heard live presentations from nine others, all of whom expressed fears the bill in its current form will not work.
More than 30 NGOs have also backed those concerns.
The bill is intended as a binding statement that Ireland will reduce greenhouse gas emissions to net zero by 2050.
Emissions would be at the minimum possible and any not preventable would be offset by natural or mechanical means of removing the greenhouse gases, mainly carbon dioxide, from the atmosphere.
A series of increasingly tight "carbon budgets" would be set, limiting the emissions allowable over five-year periods.
Each government department, and agencies and activities under its remit, would be allocated a portion of the budget within which they must operate.
Loose and vague wording throughout the bill is a major concern, however, with experts unanimous in warning that ministers and governments will only have to try to meet the targets rather than to actually achieve them.
In his submission to be considered this week, Prof McMullin, of the Engineering Faculty at DCU, says even the stated aim of carbon neutrality by 2050 is inadequate.
He says the objective must be emissions reductions in line with the Paris Agreement which requires global temperature rise to be kept well below 2C over pre-industrial levels to avoid the worst impacts of climate change.
He says the Climate Bill needs to say "the State will act to make a full, equitable and just national contribution" to meeting those goals.
"In the current draft bill, the overarching Paris Agreement temperature goals are only obliquely recognised, merely as one among many matters to 'have regard to', rather than being the very essence and test of the required national contribution," he says.
In the past two weeks, JOCCA has heard from climate law experts from England and Scotland, and Irish scientists and lawyers who have all said the bill must be strengthened to be effective.
Concerns have also been raised about the intended composition of the new Climate Change Advisory Council which will have a key role in setting carbon budgets.
Prof John FitzGerald, outgoing chair of the current council, said the way it was intended to fill the places on the council, not even Greta Thunberg would get a seat.
Professor Yvonne Buckley, a zoologist at Trinity College Dublin, said the bill needed to commit to action on biodiversity in recognition of the linked biodiversity and climate crises.
Dr James Glynn of the Centre for Energy, Climate and Marine at UCC said the ambiguous language meant it would "not be possible to measure or define whether commitments in the bill are being met".
JOCCA meets in private this week to consider all the contributions before making recommendations on the bill which the Government wants passed before Christmas.