Chief Executive of the Sustainable Energy Authority of Ireland (SEAI) William Walsh has said it is more essential than ever to accelerate the deployment of energy efficiency and renewable energy technologies, and increase sustainable energy practices across all sectors.
Mr Walsh said road transport emissions are almost back to pre-pandemic levels, and dramatic change is needed if we want to meet the climate challenge.
Almost 60% of Ireland's greenhouse gas emissions arise from using energy for electricity, heat and transport.
The Covid-19 lockdowns, less traffic, and the collapse in air transport hugely affected that.
The result was 11.5% less emissions linked to energy use and saved 4.3 million tonnes of carbon dioxide emissions.
Half of all those savings came about because so few people were using planes. Jet fuel use was cut by two-thirds.
The remaining savings resulted mainly from quieter roads.
The Sustainable Energy Authority of Ireland said petrol use fell by 26% last year due to Covid-19, and diesel 13.6%.
Meanwhile, more wind power and less peat made electricity 8.1% cleaner.
However, Mr Walsh warned that diesel and petrol use are back up to pre-pandemic levels.
He said nothing short of a societal movement to end the use of fossil fuels is now required.