The Intergovernmental Panel on Climate Change (IPCC) revises estimates of historic greenhouse gas emissions but insists its overall conclusions remain the same.
The IPCC lowered its estimate of total carbon emissions since 1860-1881 from 531 billion tonnes to 515 billion, and increased its assessment of the amount emitted since 1750 from 545 billion tonnes to 555 billion.
The IPCC had hoped to avoid making more corrections after making an embarrassing error in its analysis of Himalayan ice-melt in its previous assessment report, published in 2007.
The panel said that the adjustments do not alter its conclusion that the world has emitted more than half of the estimated one trillion tonnes of carbon dioxide which scientists believe is the maximum level at which global temperatures can be kept within safe limits.
But the changes are likely to be seized on by climate sceptics who will claim the figures show man's impact on global warming is less significant than the report initially suggested.
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