The European Commission has unveiled plans for its first climate law, which will act as the basis of the European Union's aim to make the 27-country bloc climate neutral by 2050.
Under its Green Deal agenda, the EU's executive arm wants to legislate to make its ambition of cutting greenhouse gas emissions to zero by mid-century irreversible, and legally binding for all member states.
"This climate law will set in stone Europe's position as a climate leader on the global stage," said European Commission president Ursula von der Leyen.
To establish the 2050 goal, the European Commission is proposing a mechanism for regularly raising the EU's emissions reduction target over the next three decades.
However, there is no plan to increase the bloc's overall emissions goal for 2030.
This particular point has been criticised by climate activists, who claim that delaying the upgraded 2030 target is detrimental to the bloc's credibility in the fight against climate change.
The commission only said it would present a "responsible" plan by September on how to raise its current 2030 target of reducing greenhouse gases by 40% from 1990 levels, to "at least 50% and towards 55%".
Environmental group Greenpeace voiced concerns that EU governments will "find it extremely difficult to agree a new target" before the next round of UN climate talks in Glasgow in November.
A dozen member states have also expressed their concern and have asked the commission to come up with a 2030 target "as soon as possible and by June 2020 at the latest in order to advance discussions in a timely manner".
Climate activist Greta Thunberg, who attended Wednesday's climate discussions with EU commissioners, dismissed the proposed law.
In an open letter, 34 youth climate activists, including Ms Thunberg, stressed that instead of setting long-term goals, the EU should focus on emissions of carbon dioxide right now if the world is to meet the commitments made five years ago at the Paris climate summit.
Ms Thunberg and her colleagues in the youth climate movement have been pressing governments to focus on so-called CO2 budgets – the amount of CO2 that can be emitted to keep global warming below 2C, and ideally no more than 1.5C, by the end of the century.
But scientists say countries will miss both of those goals by a wide margin unless drastic steps are taken to begin cutting greenhouse gas emissions this year.
The European Centre for Medium-Range Weather Forecasts said Wednesday that Europe had "the warmest January on record, about 0.2C warmer than the previous warmest January in 2007, and 3.1C warmer than the average January in the period 1981-2010.
"Average temperatures were especially high over large parts of northeastern Europe, in some areas more than 6C above the 1981-2010 January average."
Greenpeace also insists a 55% reduction target for 2030 is insufficient in limiting global heating to 2C.
Environmental group WWF is recommending a cut of at least 65% and is urging the EU to ban subsidies and tax breaks for fossil fuels industries as well as setting up an independent scientific body to supervise the EU's climate change plans.
Green members of the European Parliament accused von der Leyen of giving up her claim to lead in the global climate debate.
"In the face of Greta, she is breaking her promise to present ambitious climate targets for 2030," Green MEP Michael Bloss said.
To set a common trajectory and impose revised targets to member states every five years from 2023, the commission is planning to adopt legally binding legislation that can enter into force if the European Parliament and European Council, the EU body that represents governments, have no objections.
That mechanism could spark concerns among fossil fuel-dependent EU nations, which need to rejig their economies to reach the 2050 target agreed last year by all EU members except Poland.