The World Economic Forum's Dominic Waughray, Senior Director, Head of Environmental Initiatives is at the United Nations Climate Change Conference in Copenhagen and blogs his impressions.

Imagine a giant trade fair; an auditorium surrounded by many rooms and booths, each one scheduled full of talks and discussions for the next 14 days.

Such is the Congress Centre in Copenhagen where COP15 is taking place. There are hundreds of people milling around, swapping their reports, stories and memories of climate setbacks and breakthroughs. Every so often an important looking delegation of smart-suited officials swishes by. Whispers folllow after them rippling through the crowd – that was the Brazillian negotiators, some say; or was it the Costa Ricans?

There must have been over 2000 people queuing outside Copenhagen's Bella Center today, a long line drawn from across the worlds's NGOs, think tanks and climate organisations all waiting to get their badges, their access to the next two weeks of action. Luckily I bumped into an old contact and fellow "BINGO" representative near the head of the queue, who had already invested two hours of waiting and welcomed company for the final 40 minutes. On the way out, once registered, a forester I hadn't seen for years called out my name, We caught the metro back into town together. Such is the atmosphere of the COP, I suspect.

I have actually been here since Thursday, as there have been some very interesting private meetings on money, prior to the start of the COP itself. Finding the finance to tackle climate change is a pivotal part of the challenge, especially for developing countries, The numbers are huge: potentially US$1 trillion a year is required according to the International Energy Agency (IEA); US$475 billion a year for developing countries says the World Bank. (For reference total official overseas aid is about US$100billion a year).

However, in private it seems that there are progressive conversations on climate finance, which are seeking to reframe this seemingly impossible challenge. The conclusion is being reached that in essence much of the climate finance issue is in fact a massive infrastructure invesment challenge. So while the public money on offer may not come close to footing the total bill (for example, the European Commission (EC) proposes 100 billion euros for developing countries by 2020; France, the UK and others are proposing a Copenhagen Quick Start Fund of 10 billion euros by 2012), this does not simply mean that more public finance is required.

In fact, there are many useful historical lessons from the world of infrastructure and structured project finance to draw upon. Crucially, there are lessons on how limited amounts of public money can be used to buy down risk and leverage in much more private sector capital.

From an analysis of recent evidence, the United Nations Environment Programme (UNEP) in fact estimates between 3 and 13 US$ of private finance can be leveraged for every 1US$ of risk-reducing public money invested in infrastructure. So, if public-private funds can be organised in this manner, breakthroughs could be found to meet the huge climate finance challenge, without pushing developed country deficits even further into the red, and in ways that also create productive investments flows for developing countries: a result that is good for developing country GDPs, good for jobs and poverty reduction; and good for combatting climate emissions.

This new "growth" story on climate investment is creating some interesting discussions in the margins of the COP. At a dinner on Thursday night I sat next to Lord Stern. In his speech he made impressive reference to the potential for economic growth from the new investment potentially on offer; as did the excellent Connie Hedegaard, former Danish Minister for Energy and Climate now President for COP15 and soon to be the EC Commissioner for Climate, speaking at the same event.

Times are definitely changing. On Friday there was a private conference on the same topic – finding the finance – hosted by the large Danish Pension Fund ATP; and another similar private session again this morning, this time hosted by the Asian Development Bank (ADB) and the Indian research organisation Teri, attended by Rajendra Pachauri.

At the end of both these private sessions (notably both on the fringes of the COP itself), ATP officials announced they would place 1 billion euros into a new clean infrastructure fund for developing economies, provided that other institutional investors join in too, and that aid finance organisations such as Regional Development Banks offer public finance products to help buy down the risks of their investments in developing countries.

I had some good conversations with the people at ATP (one over an excellent sushi – from my sample of two, the restaurants in Copenhagen are really first class) and they are perfectly serious about this; ATP are expert at risk analysis and would not put any of their contributors' pensions plans at risk; however the ability to generate reliable risk adjusted returns over the lifetime of, say, a large windfarm, would match their aspirations perfectly. I wonder if we are seeing the birth of a new clean investment paradigm for developing countries here in Copenhagen – how apt it is for a Danish institutional investor to be taking the lead.

Naturally, as the Forum's work on climate finance so far this year has helped to open up the debate to these public-private possibilities (see the reports at http://www.weforum.org/climate), we will seek to help the various stakeholders taking the lead in this space to design and develop these new fund ideas during 2010, in order to create maximum benefit for all. Exciting times.

Tomorrow, Day 2, I will try to set out briefly where the key countries seem to be at, once all their opening positions become clear. Follow me on Twitter @dwaughray