The truth is there is no simple answer. Take your pick: low levels of capital investments, tariff barriers, lack of incentive policies, fluctuation price of oil, poor social marketing, instability in the carbon credit market, absence of standards, etc.

Looking for solutions, the folks at McKinsey and Co. think stakeholders would do well to focus on networking and sharing resources.

Listen to the Harvard Business Review and they'll tell you the US needs to spend more time investing in social entrepreneurs in the developing world and less playing the role of incubator.

Although he has patiently and politely dedicated the better part of an hour to our conversation, I know that the moment he hangs up he will be off to complete a million tasks on his to-do list.

Mulcahy has good reasons to be in a hurry. The first one is that he cheated death seven years ago following a really bad accident, so he’s a man on his second chance.

The second reason, which is linked to the first, is that he is determined to bring energy-efficient cookstoves to the world’s 2.4 billion people who sit at the bottom of the world’s energy ladder. They are the poorest of the poor who lack access to modern fuels and must make do with wood, charcoal, and animal dung to meet their everyday energy needs.

It's been described as the Swiss Army knife, or the "killer app" of climate solutions.

Now, leaders of the G20 have a chance to put it on the map!

Conor Fox thinks otherwise.