Carbon capture and storage could help the UK's largest steelworks - Port Talbot in Wales - make a big reduction in its CO2 emissions.
Tata Steel says it is committed to cutting its impact on the environment and climate change.
Prof John Gibbins told the BBC that carbon capture and storage (CCS) was the answer for the site.
The director of the Carbon Capture and Storage Research Centre said new technology would allow the plant to make low or zero carbon steel beyond 2050.
He added that CCS would take two to three years to implement, and cost between £500million and£1billion.
Prof Gibbins went on: "This is something that will preserve jobs, real jobs. What needs to be done, is for the Welsh Government first of all to latch onto the idea. This is crunch time."
But Cardiff University Business School economics professor Calvin Jones claimed that CCS would not work at Port Talbot.
Storage sites in the North Sea
He said: "There is simply nowhere near to store the carbon. Newly-leased UK storage sites are all in the North Sea.
"This will require either an entirely new CO2 pipe-distribution network, or a fleet of CO2 carrier ships to take Port Talbot's CO2 to where it can be geologically stored.
"Either will add very significantly to steelmaking costs."
Both professors agreed Port Talbot's carbon emissions needed to be addressed.
Prof Jones said there were alternatives.
He said: "There is some steel-making under development using hydrogen instead of coke. For example, Volvo are procuring this for their cars.
"This of course requires a surplus of hydrogen, which can only be made in a zero-carbon way with green electricity.
Slow to develop green electricity
"Unfortunately, Wales has been slow to develop green electricity. South Wales has one of the highest-carbon electricity supplies in the UK.
"So again, there would need to be, probably, billions in investment in and around the area to make this a reality for Tata.
"We have a lot of catching up to do."
Tata Steel said its ambition was to produce net-zero steel by or before 2050, and to have reduced 30% of CO2 emissions by 2030.
A spokesman added: "The company continues to make progressive strides in reducing the environmental impact of its processes through innovation, investment and collaboration.
"Additionally, its steel products remain critical not only for UK manufacturing supply chains, but also in the UK's transition to a green economy."
The UK Government said last month that the CCS sector could support up to 50,000 jobs in the country by the end of this decade.
Scottish Cluster
Storegga is a key partner of a portfolio of carbon-capture and hydrogen-production proposals known as the Scottish Cluster.
The heart of the cluster is known as Acorn, which takes in key facilities across the north-east as well as former oil and gas pipelines and North Sea fields that could be used to store CO2 permanently and safely.
Huge dismay met the UK Government's decision to snub the north-east in a £1billion funding competition last year which saw rival projects in England successful, leaving the Scottish Cluster as a reserve.