It's been a hive of activity here at Davos this week as business leaders and politicians discuss some of the biggest global issues on the table in 2010.

Understandably there was concern that with so many important issues vying for attention -- and with some of the disappointments of Copenhagen -- climate change would have slipped down the agenda.

But it's clear from conversations with business and political leaders, my own clients, as well as many of the main plenaries and side events that carbon is still a burning issue here.

The last couple of days here have seen a real focus on climate change and I wanted to share four key takeaways:

Firstly, it's important to reflect on Davos in the context of Copenhagen and Mexico.

Felipe Calderon, Mexico's president, summed up the general view here when he said of Copenhagen that it "was not enough" and that "nobody was satisfied with it." But Calderon, who will officiate over the next round of climate change talks in Mexico at the end of this year, was also clear that while a disappointment, Copenhagen was not the end of the road for a global deal on climate change.

I agree with Calderon's assessment that Copenhagen failed to deliver on many of its promises, but that hope remains in 2010. My view is that from the ashes of Copenhagen has come the shell of an agreement, in the form of the Copenhagen Accord. This short document now needs to be filled in with both the details of a future climate change deal and with the political legitimacy necessary to be accepted by heads of state.

Secondly, delivering a global deal is not going to be easy, but progress is being made and in many cases companies have decided to ramp up their investments. Here at Davos, it's clear that to make progress governments and businesses will need to be convinced of the economic viability of any proposed regulatory plans.

To quote Calderon again, the mood here is that "the economic costs associated with trying to tackle climate change are central to the challenges facing governments." To ensure a deal, future plans will need to ensure that no country is unfairly penalized for compliance and that there are sufficient economic incentives.

Thirdly, while you could pessimistically view the absence of clear and definitive price signals as a blocker to investment I think there is an alternative, more pragmatic view. From our conversations with CEOs here at Davos, we know that that even in the wake of Copenhagen they are ramping up in the face of expanding national and regional emissions regimes which compel them to address climate change today, rather than wait for absolute clarity on a possible global deal and carbon price.

What is clear is that business leaders are demanding more certainty from policymakers. Crucially, they are pressuring politicians to deliver the clear price signals that are needed to stimulate investment. As we heard Renault-Nissans CEO Carlos Ghosn say this week: "In the private sector, we need clear targets."