Ministers from Europe's three biggest economies made the exceptional move in a commentary published by the Financial Times, the Frankfurter Allgemeine and Le Monde.
"If we stick to a 20-percent cut, Europe is likely to lose the race to compete in the low-carbon world to countries such as China, Japan or the US - all of which are looking to create a more attractive environment for low-carbon investment," they warned.
The commentary was written by German Environment Minister Norbert Röttgen, his French counterpart Jean-Louis Borloo and Chris Huhne, the British climate change secretary.
Alone among the major economies, the EU has vowed to cut its emissions of man-made heat trapping gases by 20 percent by 2020 over 1990, the benchmark
year used in UN climate negotiations.
The EU has until now offered to go to a cut of 30 percent if other industrialised powers follow suit. The proposal was put on the table, but not reciprocated, at December's world climate talks in Copenhagen.
The joint commentary did not specifically suggest that the 30 percent should be a unilateral initiative, saying only that the EU "should raise its emissions target." Achieving emissions cuts carries an economic cost in order to achieve greater energy efficiency and switch to cleaner sources.
In May, proposals by the European Commission to deepen the target to 30 percent were resisted by the Brussels business lobby on the grounds of cost, and by French and German economy ministers, who defended the previous policy of a quid pro quo.
Röttgen, Borloo and Huhne said that a 30-percent cut would not only help meet the international target of limiting global warming to two degrees Celsius (3.6 degrees Fahrenheit). It would also spur green investment by boosting the cost of carbon
pollution, they said.
Carbon traded in the European emissions market had fallen by 11 percent from pre-crisis levels, a price judged too low to stimulate capital in green jobs and technologies.
"Because of reduced emissions in the recession, the annual costs in 2020 of meeting the existing 20 percent target are down a third from €70 billion ($89 billion) to €48 billion," the trio said.
"A move up to 30 percent is now estimated to cost only €11 billion more than the original cost of achieving a 20 percent reduction. Furthermore, these costs were calculated on the conservative assumption that oil will cost $88 a barrel in 2020.
"Given the current constraints on supply-side investment, rapid growth in consumption in Asia, and the impact of the Gulf of Mexico oil spill, oil prices may well rise further. Under one IEA (International Energy Agency) scenario, the price could reach a nominal 130 dollars a barrel," they said.