BERLIN (Reuters) - The German Environment Agency (UBA) is doubtful about the environmental benefits of introducing incentives for drivers of older diesel vehicles to trade them in for newer models, a German newspaper reported on Saturday.
Chancellor Angela Merkel is due to hold a high-level meeting on Sunday to discuss whether to require the car industry to carry out costly hardware upgrades for older diesel vehicles to reduce inner-city pollution, government sources said on Friday.
Transport Minister Andreas Scheuer, a member of Merkel's Bavarian CSU allies, favours incentives to exchange older vehicles for newer ones to reduce overall pollution caused by the fleet of cars on the road and to avoid driving bans.
But Frankfurter Allgemeine newspaper cited an internal paper from UBA as saying this would not help much: "In the best case scenario, an exchange premium would only reduce nitric oxide pollution by 0.7 micrograms per cubic meter."
That would be a very small amount compared with the overall pollution, which is at between 73 and 78 micrograms in cities like Stuttgart or Munich, the newspaper cited UBA as saying.
UBA, which is Germany's main environmental protection agency, was not immediately available for comment.
Older diesel vehicles such as those of the Euro-4 standard sometimes have lower emissions than the more modern Euro-6 standard diesel vehicles.
Scheuer has not ruled out the possibility of a retrofit with catalysts, which is favoured by the Environment Ministry - run by the Social Democrats - but he considers that solution to be more complicated technically and more expensive.
Merkel has tasked Scheuer with finding a solution to make older diesel cars cleaner and to avoid large-scale bans on diesel cars.
The car industry has lobbied against equipping old diesel models with extra emissions control technology because that could cost billions of euros.
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(Reporting by Michelle Martin; Editing by Gareth Jones)