A high-level government advisory group’s findings that it is possible to raise as much as $100 billion a year to fight climate change by 2020 was welcomed on Friday.

Norwegian Prime Minister Jens Stoltenberg and his counterpart from Ethiopia, Meles Zenawi, said in a study that the goal set by industrialised nations could be a challenge, but that it is feasible.

“Nobody should believe that it is easy to mobilise $100 billion a year from 2020, but the report shows that it is doable — even more so as the reality is that not investing this money will turn out to be more expensive,” said Connie Hedegaard, the European commissioner for climate action.

She said the European Union will “constructively engage in finding models that can secure that the world delivers, as we are already delivering on our fast start commitments for 2010-2012.” The climate change summit held in Copenhagen last December agreed to provide $30 billion for the 2010-2012 period to help developing countries fight climate change. The climate financing would increase from $30 billion to $100 billion by 2020.

The findings by the High-Level Advisory Group on Climate Change Finance headed by Mr. Stoltenberg and Mr. Zenawi proposed various ways to allow governments and the private sector to work together to raise the huge amount by 2020.

Ms. Hedegaard pointed out that the study’s new and innovative sources of revenue crucially depend on the future carbon price and the proportion of emission allowances that is auctioned.

“In this context, the European Commission reiterates that at least half of the revenues from the auctioning of EU emission allowances should be used to finance climate action, including in developing countries,” she said.

The Prime Ministers gave the study to Secretary General Ban Ki-moon at the United Nations headquarters in New York as part of U.N. preparations for a new round of climate negotiations scheduled to take place next month in Cancun, Mexico.

Mr. Ban said the study contained “financing options that are both financially feasible and politically viable.”

“It will need sustained political will, appropriate public policy signals for the markets and financial ingenuity,” Mr. Ban said in response to the study.

He called on all countries to demonstrate a strong commitment to fight climate change.

Mr. Ban also urged the G20 summit in Seoul next week to discuss climate change directly. Mr. Ban will take part in the meeting with national leaders of the world’s 20 richest nations.

He said in a letter sent to the G20 summit that the group could lead the way “by delivering on the fast start funding targets for the 2010-2012 period.”

Britain’s charity organisation Oxfam, meanwhile, said that raising public money to help developing countries fight climate change is possible without costing the taxpayer.

“The next step is for political leaders to lay out a clear roadmap for making this funding a reality,” Tracy Carty, Oxfam’s climate change policy advisor, said in a letter to the British government.

Greenpeace International said the feasibility study has wiped out developed countries’ excuses not to meet their financial commitments to provide green technology to developing countries.

“It is now clear that it is both technically feasible and politically possible for governments to raise substantial amounts of public money for climate action from new mechanisms, such as pricing emissions from international air travel and shipping,” the group’s Steve Herz said.

“In fact, developed countries can meet their Copenhagen commitments without raiding existing aid programmes, and without counting the face value of loans or private sector investments, rather than their grant component,” he added.