Northern Ireland needs an administration committed to tackling climate change, says the head of the body that advises the government on the issue.
Lord Deben was speaking as his Committee on Climate Change recommended an ambitious new UK target.
It urged legislation that would mean net zero greenhouse gas emissions by 2050.
The government has promised to consider the advice carefully.
It would require the entire economy to switch away from fossil fuels, as well as developing technologies for carbon capture and storage.
Northern Ireland is the only devolved administration which does not have its own climate change legislation and emissions targets.
It is covered by Westminster laws and does contribute to a wider UK target which, until now, has been to cut emissions by 80% from 1990 levels by 2050.
Lord Deben said the collapse of the power-sharing government at Stormont made change more difficult. He also said when devolution returned Northern Ireland it would need a different approach.
"We'll need a government that is committed to dealing with climate change and that hasn't always been true," he said.
There's been political resistance in some quarters to Northern Ireland-specific climate legislation.
Concerns have been raised about the potential impact on the competitiveness of the agri-food sector and our reliance on cars for rural transport.
The advice announced by the Committee on Climate Change would require further societal and policy change.
It would mean:
- Generating even more renewable energy
- Making the switch to electric vehicles earlier
- Making buildings more energy efficient
- Cutting emissions from agriculture, aviation and transport
In Northern Ireland, emissions from agriculture will be a challenge. The economy here is heavily reliant on the sector, which is livestock-orientated, and has the highest agricultural emissions in the UK.
And our reliance on fossil fuels for energy generation is something the committee report says will have to be addressed if the UK is to meet its overall 100% net zero target.
The committee's ideas were sought by the Westminster and devolved administrations.
They asked for advice on how to live up to the UK's endorsement of the Paris Agreement on climate change.
The agreement committed governments to keep global warming to below 2.0C (3.6F) above pre-industrial levels and to pursue policies that would limit it to 1.5C.
Lord Deben, better known as former UK environment secretary and agriculture minister John Gummer, said old arguments around climate change science had ended.
"People have begun to understand that this is scientific certainty," he said. "This is what is true. We have got to deal with it.
"The old arguments have fallen away, so I would hope that when you have an assembly that we will be able to work with it with a much greater degree of co-operation."