Private funds should be further mobilized in the global fight against climate change, said European Investment Bank (EIB) President Werner Hoyer while addressing media at the on-going Paris Climate Change Conference (COP21).

"Everything, from the other sustainable development goals to the climate goals, makes it very clear -- we can do this only if we mobilize private funds," said Hoyer.

Speaking of the future of climate project financing and how to get more private investors involved, Hoyer said the idea of Green Bonds should be "further developed," and "the depth should be dug deeper."

In 2007 the EIB became the first financial institution to issue an environment-themed bond by launching the Climate Awareness Bond. Money raised through this type of bonds can only be allocated to so-called "green projects," including renewable energy, energy efficiency, sustainable agriculture and other forms of adaptation to climate change.

Having raised 7.6 billion euros (8.05 billion US dollars) in 10 currencies so far, the EIB remains one of the largest issuers of Green Bonds.

The EIB aims to establish itself as a leader in financing climate actions. Earlier this year it announced a new climate lending strategy and agreed that 35 percent of future lending in countries most vulnerable to climate change will support climate-related projects.

The bank expects to provide a total of 100 billion euros for investment in such projects over the next five years around the world, according to Hoyer.

"I believe by far we are the biggest multilateral development bank acting in this field, and we have a lot of expertise over many years, so we can bring in our experience and our experts," he added. "We must develop intelligent financial products which make it interesting for private investors to join us."

Hoyer's remarks echoed the World Bank's call for greater private sector engagement ahead of the Paris climate talks.

"Public funds alone can't meet the challenges of the future," the World Bank said in a statement.