Global warming could hit critical levels within five years, the world's leading science organisations said as they warned that climate change had not stopped for Covid.
atest assessments by the group show a 24pc chance of a temperature rise exceeding the feared 1.5C threshold by the end of 2024.
Reaching that point does not necessarily mean there is no going back as temperature can fluctuate from year to year so global warming trends are tracked over longer periods.
But scientists say the forecast reinforces the need for "urgent and concerted action by all countries and across all sectors".
A global temperature rise of 1.5C above pre-industrial levels is the maximum the Earth can cope with before escalation of extreme weather events, ice sheet loss, sea level rise, floods and fires.
Ireland is one of almost 200 signatories to the Paris Agreement which binds countries to work collectively to keep temperature rise below 2C and ideally to 1.5C.
These latest assessments come from the World Meteorological Organisation, the Intergovernmental Panel on Climate Change, the UN Environment Programme, Unesco, the Global Carbon Project and the UK Met Office working under the joint banner of United in Science.
They say that while emissions of carbon, the most problematic greenhouse gas, are down 4-7pc globally this year due to reduced economic activity during Covid restrictions, the concentration of carbon in the atmosphere is higher than last year because of the cumulative effect of emissions over many years.
They also warn that 2016-2020 is set to be the warmest five-year period on record with below average Arctic ice formation in each of those years.
"This has been an unprecedented year for people and planet," said UN secretary general Antonio Guterres. "The Covid-19 pandemic has disrupted lives worldwide. At the same time, the heating of our planet and climate disruption has continued apace."
Sadhbh O'Neill of the Stop Climate Chaos Coalition said the report was an "alarming" reminder of the crisis ahead.
"The implication for Ireland is that we have to step up and do our fair share," she said.
"While the Programme for Government is ambitious in a way that previous programmes have not, we still haven't seen emissions reductions kicking in.
"When you think of the disruption we experienced during the Covid restrictions, with entire town centres shuttered and traffic disappearing, yet the reduction in our energy demand was minute and our agricultural output and associated emissions increased.
"It shows the scale of the challenge in decarbonising the system. Every part of it needs to be transformed."
The report was published as environmental groups here welcomed a ruling from the European Court of Justice that planning permission for the controversial Shannon LNG (liquefied natural gas) terminal should not have been extended without the project being subject to a fresh environmental assessment.
The case was taken by Friends of the Irish Environment.
The project not only proposes to import fossil fuels but would source the gas from fracking operations overseas when fracking is banned here on environmental and health grounds.