Fianna Fáil leader Micheál Martin has said he "walks a lot" to bring down his carbon footprint.
Hitting out at the Government's efforts to tackle climate change, Mr Martin said there has been "a lot of rhetoric" and "ambitious plans" but little has been implemented.
The Government recently published its long-awaited climate action plan and has established a Climate Action Delivery Board to ensure the 180 actions set out in the document are introduced.
These actions include efforts to have around a million electric vehicles on Irish roads by 2030 and make Ireland carbon-neutral by 2050.
When asked what he has done to reduce his own carbon emissions, Mr Martin said:
Mr Martin does not believe that climate change, which is mainly under the remit of Communications Minister Richard Bruton, should be made into its own stand-alone Department.
"Climate change has to be interdepartmental. For example, it’s come to our attention. I’ve met with various groups, that we’ve had a disjointed approach so there are units in certain government departments that shouldn’t be there. You do need to reconfigure government to bring various dimensions together under the one roof."
"We’ve had the publication of ambitious plans, but when it comes to actually operational implementation, we do have to wonder that a country that 30 years after the introduction of the smoky coal ban cannot finish the job and do a very basic thing in terms of public policy, provide for clean air through a policy that has proven to work in this city and elsewhere but for some reason the government baulked because a number of letters came in the door from vested interests.
"That to me, gives the lie to the rhetoric that we’ve got from government in relation to climate change and that particular agenda.
"I think from a political point of view, I do get frustrated at the lack of real urgency around it. The smoky coal ban to me, surely to hell they could go off and do it," he said
Asked whether he would like to merge the Departments of Finance and Public Expenditure, Mr Martin said his party would produce a broader paper on the reconfiguration of government.