By Andrew Walker
BBC economics correspondent in Buenos Aires
Wind energy represents a business opportunity for some companies
Many business people are worried about efforts to tackle climate change.
Some of the key tools to curb greenhouse gas emissions could raise the cost of energy.
Carbon taxes or the capping of industrial emissions could raise costs.
Some businesses, like BP, say they have saved money by improving their own energy efficiency.
But there is a whole group of businesses that stand to do very well out of the climate change agenda.
The fact that the Kyoto Protocol comes into force in February - imposing limits on most developed countries' emissions - means those opportunities may be close at hand.
Take electricity generation.
Wind and solar power and small hydroelectric plants do not produce greenhouse gases. (Nor do nuclear or large hydroelectric projects, but they are more controversial for other environmental reasons.)
These "renewable" energies account for a very small proportion of current worldwide power generation, but they are likely to grow.
Companies in these businesses see a huge opportunity ahead of them.
This is not a sector where people will express a hint of doubt about the science of climate change - which other business people sometimes do.
Many argue that developing countries should not rely on fossil fuels
Econergy provides advice and investment funds for what chief executive Tom Stoner calls clean energy.
Wind and solar feature and there is one project which involves burning waste from a sawmill to produce electricity; it is waste that would otherwise rot or be burned and give off greenhouse gases anyway.
He says developing countries need investment in their energy infrastructure, otherwise they will not develop.
Nevertheless, it needs to be clean energy he says; the world cannot afford the additional emissions if developing countries grow on the basis of fossil fuels.
And of course businesses like his will thrive in an environment where that approach is widely believed.
And there is the unglamorous business of using energy efficiently.
The European Insulation Manufacturers' Association has sent its boss, Horst Biedermann, here to Buenos Aires.
He says that in the European Union buildings produce more emissions - 40% of the total - than either transport or industry.
Buildings produce more emissions in the EU than transport
The firms he represents can fix that problem.
He acknowledges that making insulation produces a lot of greenhouse gas - because glass or stone has to be heated to high temperatures before it is made into mineral wool.
But, when installed, the savings are greater by a factor of 20, he says.
So, for sure there are some businesses who see the effort to tackle climate change as cloud on the horizon. But for a few, it is a little ray of sunshine.