The commission’s proposal includes a reduction target of 40 percent of domestic emissions by 2030, compared to 1990 levels, plus a renewables target of at least 27 percent and energy savings of 30 percent.

“We are in the process of de-carbonising Europe's economy,” he said.

Barroso noted that the EU aims to spend 20 percent of its overall 2014-2020 EU budget on climate action.

He also announced plans to set aside more than €3 billion in grants to support sustainable energy in developing countries over the next seven years.

Organised by the UN Secretary-General Ban Ki-moon, the summit aims to mobilise political will ahead of a legally binding international climate contract in Paris. It is the largest gathering of leaders on climate change since the failed 2009 summit in Copenhagen.

But critics says the pledges announced, despite the impassioned speeches from global leaders like US President Barack Obama, fall short of what is needed to limit the global rise in temperature to 2 degrees Celsius.

“The EU brings nothing new to the negotiating table yet still pretends to be a climate champion,” said Jean-Cyril Dagorn, a climate change expert at Oxfam.

He says the EU relies too heavily on fossil fuels, a major contributor to green house gas emissions.

Another issue is that developing countries are hoping to tap into a so-called Green Climate Fund, set up in 2010, to help them counter climate change.

NGOs say the fund needs at least €11 billion in the first three years of operation. To date, it has €1.8 billion.

Prior to the summit, Germany and Sweden agreed to place money into the fund. At the summit, governments and businesses from Denmark, France, South Korea, Norway and Switzerland pledged a total of around €1 billion for the fund.

The world's two largest carbon emitters, China and the US, also made some announcements.

China’s Vice-Premier Zhang Gaoli said the country would make greater efforts to address climate change by either capping emissions or have them peak “as soon as possible”.

Last year, China invested more in renewables at €43bn than Europe at €37bn, according to the Financial Times.

Gaoli also pledged €6 million to help developing countries fight climate change.

US president Barack Obama, for his part, said the US would help to ensure a global contract is reached in Paris in October.