Greenhouse-gas emissions across the EU declined by 23% between 1990 and 2014, while the economy grew by 46%, according to data from the European Environment Agency (EEA).
The EU has a target to reduce emissions by 20% by 2020 compared with 1990 levels, and in 2013 the bloc had already achieved 19.8% reduction. Estimated emissions for 2014 show a further decline, to 23%.
The agency's report cites a warmer winter as a key reason for the improvement in emissions reductions last year.
The 2020 target is split into three areas; renewable energy, GHG reductions and energy efficiency. Thirteen member states are now on track to deliver their national targets in all three areas, compared with nine in 2013, the agency found.
The UK is one of eight countries unlikely to meet its renewable energy targets. The others are Denmark, France, Ireland, Luxembourg, the Netherlands, Portugal and Spain. Meanhwile, Belgium, Estonia, France, Germany, Malta, the Netherlands, Poland and Sweden are not on track to meet the energy efficiency target, while Austria, Belgium, Ireland and Luxembourg are falling short on reducing GHGs.
The EEA predicts that existing policies by member states mean GHG emissions are likely to be 24% less in 2020 than in 1990. If additional measures being planned across the bloc are implemented successfully, emissions could be 25% lower than in 1990, it found.
EU commissioner for climate action and energy Miguel Arias Cañete said: "We have shown consistently that climate protection and economic growth go hand in hand. This is a strong signal ahead of the Paris climate conference that Europe stands by its commitments and that our climate and energy policies work."
Beyond 2020, reductions in GHGs are projected to continue, but at a slower pace. Current measures should cut emissions by 27% below 1990 levels by 2030, but the EU has set a 40% reduction target in 2030.
The need for member states to be put in place new measures in order to meet the 2030 target is reinforced by the findings of a report from the OECD, published today. It found that the EU would need to reduce its GHG emissions by 2.8% a year to meet its post-2020 climate pledges, whereas the average annual cut between 2005 and 2012 was just 1.8%.
The OECD examined emissions reductions across its 34 member states, the EU bloc and 10 other countries, including China and Brazil, which together account for more than 80% of global GHG emissions.
It found good progress on implementing policies to combat climate change, including carbon pricing instruments, cuts to fossil fuel subsidies, investment in green technology, protection of forests and reduced emissions from factories, farms and landfill sites. Nearly all have decreased GHGs per unit of GDP, it said.
However, the pace at which such policies are being implemented is not fast enough, it concluded. The US, for example, would have to cut its annual GHG emissions by 2.3%-2.7% to meet its post-2020 targets, compared to an average annual reduction of 1.6% a year between 2005 and 2012.
Aggregate GHG emissions from OECD countries peaked in 2007 but remained above 1990 levels in 2012. Improved energy efficiency and use of renewables have been partially offset as economic growth has recovered and global demand for transport has risen, it found.
Meanwhile, emissions from emerging economies have risen significantly since the 1990s.
A "sharp acceleration of effort" is required, said OECD environment director Simon Upton.
