The European Union has said that any warming of the climate by more than 2 degrees Celsius over pre-industrial levels would be a dangerous change, bringing more damaging heatwaves, storms, coastal flooding and water shortages.

EU leaders have adopted ambitious targets to reduce greenhouse gas emissions by one-fifth by 2020 from 1990 levels to combat global warming.

But the report by German conservative Karl-Heinz Florenz, to be debated by EU lawmakers ahead of a vote on Wednesday, seeks to go further.

"All efforts to curb emissions should in fact aim at staying well below the 2 degrees target, as such a level of warming would already heavily impact on our society and individual lifestyles," Florenz wrote.

"The window of opportunity for starting the mitigation efforts needed to achieve the 2 degree target will close by the middle of next decade," he added.

The report called for the "rapid development" of eco-labelling to allow shoppers to trim their carbon footprints, and it touched on the divisive issue of so-called food miles.

"Such initiatives should ideally be based on shared standards and should also take into account the embedded greenhouse gas emissions from imports," Florenz said.

Environmentalists recommend that people eat as much locally produced food as possible, ending carbon-intensive air-freighting of fruit and vegetables around the world.

But many developing countries, especially in Africa, say communities of farmers have become dependent on the lucrative trade, which they contend is balanced out by less carbon-intensive farming methods.

The report highlighted the danger of reaching tipping points that would accelerate climate change, such as the melting of Siberian tundra, which is expected to release huge amounts of climate-warming methane into the atmosphere.

It said countries would have to take more extreme action than suggested by the last major report by the Intergovernmental Panel on Climate Change (IPCC) in order to avert that threat.