The European Union has decided it would not ban foreign airlines that have refused to share their carbon emission data from entering EU airspace.
However, it said stringent financial penalties would be imposed if these failed to comply with the laws by January 2013.
Refusal to share carbon emission data is a violation of the EU's emissions trading system laws.
In January, the 27-member EU bloc had decided to include the aviation sector under the EU ETS.
Since then, it has asked all domestic, as well as foreign airlines, to comply with the changed laws and share their carbon emission data with Brussels.
The airlines would now need to follow a specific benchmark on carbon emissions or pay a carbon tax, along with a penalty.
However, India and China have refused to share the data.
The two nations also indicated severe implications if the EU banned their airlines from entering its airspace.
"In the case of 2011 data, the penalties were not the same throughout the EU, but were determined by each member state. These apply to airline operators administered by the respective member state.
Overall, however, it can be said the penalties for this violation of EU law take the form of financial penalties. No airline will be banned from flying to the European Union because it did not submit their 2011 data," Valero Ladron, EU spokesperson for climate action, told Business Standard.
He added airlines that would continue to emit more than the prescribed cap on emission would be asked to either reduce emissions or pay for the emission.
Airlines can either make the payments on their own, or pass on the costs to passengers. This would mean a one-way ticket from Brussels to Delhi would cost an additional ^1.55.
"We all have to take action as quickly as possible to address this source of emissions," Ladron said, adding emissions from international aviation in Europe had doubled since 1990.
These, he said, may even triple by 2020.
Officials in the Ministry of Commerce & Industry have said India would not follow any unilateral decision by another country, only adhere to laws currently being worked out by the United Nations' International Civil Aviation Organisation.
The civil aviation ministry had said no airline would share emission data with the EU. Civil aviation minister Ajit Singh had earlier stated in case the EU imposed any restriction on Indian carriers, India would respond strongly to this.
At present, only two Indian carriers -- Air India and Jet Airways -- fly to Europe. A query sent to Jet Airways went answered.
"For more than 15 years, the ICAO has tried to tackle the aviation sector's increasing contribution to greenhouse gas emissions.
"But after years of little progress at the international level, the European Union has decided to act. We are, however, still pushing for a global agreement under ICAO. The day ICAO succeeds, we will modify our legislation accordingly," said Ladron.
The EU ETS, introduced on 1 January 2005, earlier covered sectors such as energy-intensive industrial installations.
Following the EU legislation adopted in 2009, air operators would also be covered.
According to the new laws, every year, airlines would receive tradeable allowances covering a certain level of carbon dioxide emissions from their flights.
At the end of every year, operators must surrender a number of allowances equal to their actual emissions during that year.