The world still faces a financing gap of some 350 billion U.S. dollars for clean energy development necessary to curb global warming, despite the fact that investment last year was only slightly affected by the financial crisis, the World Economic Forum (WEF) said on Thursday.

In a report released at the organization's annual Davos meeting, the WEF said an investment of around 500 billion dollars is needed annually in order to move to a low-carbon energy infrastructure which is required to restrict the increase in global average temperatures to 2 degrees centigrade.

Investment in 2009 stood at some 145 billion dollars, down only 6 percent from 155 billion dollars in 2008, as the shortfall created by the financial crisis was largely filled by the launch of green stimulus initiatives around the world.

In addition, the Copenhagen Accord, which was reached by participants at the UN climate meeting in December, contained a commitment by developed countries to invest 100 billion dollars in developing countries.

"While the next few years are likely to see record investment activities, a significant financing gap of 350 billion dollars still exists. To unleash adequate funds to bridge this gap, appropriate policy mechanisms are required," the WEF said in a statement.

The report, titled "Green Investing: Towards a Low Carbon Energy Infrastructure," provides policy-makers with a toolkit consisting of 35 different policy mechanisms, which can be used to promote various clean energy sectors.

The mechanisms, which can be chosen based on stage of technological development, include the establishment of national laboratories or research centers; requiring public entities to procure clean energy or use emerging efficient technologies; programs designed to reduce the cost of private lending and improve project economics; and microfinance.