Unilever and Coca-Cola Co have joined forces on a plan to cut greenhouse gas emissions, launched at the UN climate change summit in Copenhagen.

The two global firms hope to change the behaviour of customers and suppliers with the guide, which has been launched as businesses urged governments at the summit to provide a lead on controlling greenhouse gases.

Talks at Copenhagen were suspended today (14 December) after a bloc of developing nations walked out in protest at what they believe is unfair treatment by richer countries.

The consumer goods initiative - 'Moving Fast to a Cleaner Climate: A manager's guide - How consumer goods companies can tackle climate change' - has been published to encourage businesses to take a "big-picture approach" to reducing greenhouse gas emissions, Coca-Cola Co and Unilever said.

"There are three compelling reasons why consumer goods companies should play their part alongside other industries in tackling climate change," they said.

"The sector contributes directly and indirectly to climate change, through the sourcing or production of products and the way the products are used by consumers. Across the value chain, we estimate that emissions in this sector could total as much as 5bn tonnes of CO2.

"Insights into consumer needs offer the sector the opportunity to reach beyond its own production activities to help consumers mitigate climate change."

Coca-Cola and Unilever said they are both using a "value chain approach" to mitigate their impact on the environment.

"The most effective way to reduce emissions may involve changing the way you operate, the kind of products you sell or the way you market them to consumers," they said.

The Coca-Cola Co said the recent launch of its PlantBottle packaging is a "key milestone" in its plan to decouple its packaging from fossil fuels and carbon.

The material used in the plant-based bottle reduces dependence on non-renewable resources and is completely recyclable. It can also cut Coca-Cola's carbon emissions "significantly", the soft drinks giant said.