Fluorinated gases (also known as HFCs or F-gases) only contribute around 2% of greenhouse gases today but if business continues as usual, that figure could rise to between 9% and 19% by 2050.
An interim review of a 2006 EU law to restrict the use of F-gases in Europe, seen by EurActiv, is recommending new policies to promote "further reductions of F-gas emissions" for mobile air conditioning systems in cars, ships, trains and refrigerated transport systems.
"Bans have been the most effective type of measure so far and resulted in significant and measurable reductions of F-gas consumption and hence emissions," says the report by German research firm Öko-Recherche.
But it also lists alternatives. "The option to establish step-wise gwp [global warming potential]-weighted limits for the placing on the market of HFCs has been identified to show the highest emission reduction potential," the report says.
An EU official confirmed to EurActiv that both options had advantages and were being considered for recommendation in an impact assessment that will be published in September or October.
In practice, either could lead to a 'phase-out' or 'phase-down' of some of the worst-polluting F-gases, over an undetermined period, and their replacement with natural refrigerants such as ammonia, propane, butane and CO2 (a relatively harmless substance when used this way).
The most widely-used F-gas, HFC 134a, is over a thousand times more potent than CO2 in causing global warming.
A phase out of HFC 134a started this year under a 2006 EU directive banning its use in newly "type-approved" cars. By 2017, the directive will apply to all cars.
Industry sources say a wider ban on F-gases could cost Europe's businesses hundreds of millions of euros, and plead for more time to assess the effectiveness of existing legislation.
Europe's refrigeration, air conditioning and heat pump industry has an annual turnover of around €30 billion and employs around 200,000 people.
EurActiv understands that one industrial manufacturer estimates the cost of the last phase-out of ozone-depleting CFCs in the late 1980s and 1990s at around $100 million.
The cost of phasing out F-gases would "probably be much higher," an industrial source added, "because HFCs share a lot of the same characteristics as the ozone-depleting refrigerants".
Environmentalists dispute such figures. "It only costs a small amount more and you have to look at the whole lifecycle," Marc Chasserot, director of the environmental marketing and communications firm Shecco, told EurActiv.
He noted that many F-gas manufacturers were already investing in more energy-efficient natural refrigerants to spread their risk.
The wider green argument - that climate change is moving faster than industry or government - also seems to have received backing from the Öko-Recherche report.
This has led to accusations of bias.
The European Fluorocarbon Technical Committee (EFCTC), which represents F-gas manufacturers, has sent a letter to Brussels complaining that the expertise of the Öko-Recherche consultants was in "technical analysis and promotion of alternative refrigerants rather than the fluorinated gases".
"This could potentially conflict with the work to be carried out for this report," the letter continued.
But environmental NGOs claimed that it was they who had been denied access to the stakeholder consultation.
"I was locked out of the stakeholder group and so were a number of NGOs," David Holyoake, legal advisor to environmental group Client Earth, told EurActiv.
"That was the only opportunity for formal engagement with Okö-Recherche - who were also sat at the table - or the Commission."
After the release of its final impact assessment report this autumn, Brussels will decide whether or not to propose changes to the F-gas regulation later in the year.