The 'very likely' in this context means a probability of greater than 90 per cent, says the Intergovernmental Panel on Climate Change.
Here's a link to the IPCC policy-maker's summary and the IPCC website.
An excerpt from the BBC story:
The scientific body, in a report released in Paris today, forecasts temperatures will probably rise by between 1.8-4C (3.2-7.2F) by 2100.
But another study released on the eve of publication suggests its previous reports may have been too conservative.
Dr Rajendra Pachauri, the IPCC chairman, said: "It is extremely encouraging in that the science has moved on from what was possible in the Third Assessment report.
"If you see the extent to which human activities are influencing the climate system, the options for mitigating greenhouse gas emissions appear in a different light, because you can see what the costs of inaction are," he told delegates at the launch of the report.
Strong language
The document released today by the IPCC is intended to be the definitive summary of climate change science.
The agency has said it would use stronger language to assess humanity's influence on climatic change than it had previously done.
In 2001, it said that it was "likely" that human activities lay behind the trends observed at various parts of the planet; "likely" in IPCC terminology means "between 66% and 90%".
Now, the panel concludes, it is at least 90% certain that human emissions of greenhouse gases rather than natural variations are warming the planet's surface.
"The understanding of [human] warming and cooling influences on climate has improved since the third assessment report, leading to very high confidence that the globally averaged net effect of human activities since 1750 has been one of warming," observed the scientists.
They conclude that temperatures will probably rise by between 1.8 C and 4C, though increases as small as 1.1C (2F) or as large as 6C (10.8F) are possible.
In 2001, using different methodology, the numbers were 1.4 (2.5F) and 5.8C (10.4F).
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