The UN has released new data showing an upward trend in emission of greenhouse gases, and called for urgent action from rich countries.
Greenhouse gases are blamed for human-induced climate change
The data showed a 2.4% total increase in emissions across 41 industrialised countries between 2000 and 2004.
Britain, France and Germany were "relatively close" to achieving Kyoto Protocol targets, the UN said.
The US remained the world's biggest greenhouse gas polluter - its emissions increased 15.4% between 1990 and 2004.
Under the Kyoto Protocol, industrialised countries agreed in 1997 to cut emissions of the gases blamed for human-induced climate change to 5% below 1990 levels.
Overall emissions have decreased by 3.3% since 1990.
But this is largely because rising emissions in rich countries have been offset by the massive decline in industry in Eastern European and former Soviet countries following the collapse of communism.
And Yvo de Boer, the head of the UN climate change secretariat in Bonn, said it was "worrying" that the new data showed that even those countries' emissions had risen 4.1% between 2000 and 2004.
The figures were published as the British government released a report by economist Sir Nicholas Stern, which suggests that global warming could shrink the global economy by 20%.
But taking action now would cost just 1% of global gross domestic product, the 700-page study says.
Mr de Boer said that overall, Kyoto signatory countries had a "good chance" of meeting their targets if they moved fast to implement proposed strategies.
But he warned that the targets were small compared to the ultimate challenge, pointing to information from the Intergovernmental Panel on Climate Change (IPCC):
"It's showing us that by the middle of the century, emissions probably need to be reduced by 60% or 80%, at least by industrialised countries," he said.
"It's telling us is that we need to act on climate change very urgently or else it's going to get very expensive."
The new UN data also showed some countries were far from the hoped-for reductions.
The US originally agreed to work towards a 6% reduction from 1990 levels, but later pulled out of the protocol, saying implementing it would be detrimental to its economy.
By 2004, US emissions were 21.1% above 1990 levels and accounted for nearly a quarter of all global greenhouse emissions, the UNFCCC said - although the rate of increase of emissions had slowed in recent years.
Japan and Spain had fallen behind targets. Japan's emissions have increased 6% since 1990, despite a 2012 target of a 6% decrease.
And Spain had pledged to allow its emissions to rise 15% by 2012, but by 2004 they were already 49% above 1990 levels.
Mr de Boer pointed to Britain and Germany as positive examples, demonstrating that it was possible to sustain economic growth while cutting emissions.
"It is possible to decouple economic growth and climate change," he said.
The figures come ahead of UN-sponsored talks on the Kyoto Protocol next week in Nairobi.