From the BBC:

A UN panel has agreed a landmark report on climate change, and says the world must act hastily to prevent the worst predicted effects coming to pass.

After arduous talks in Valencia, Spain, scientists agreed a document they hope will shape debate on the next phase of the fight against climate change. ...

The text will be officially launched by UN chief Ban Ki-moon on Saturday.

Delegates to the Intergovernmental Panel on Climate Change (IPCC) summarised thousands of pages of scientific analysis, bringing together elements of the three reports already released this year, on the science of climate change, impacts and adaptation, and options for mitigating the problem. ...

Among the report's top-line conclusions are that climate change is "unequivocal", that humankind's emissions of greenhouse gases are more than 90% likely to be the main cause, and that impacts can be reduced at reasonable cost.

The synthesis summary finalised late on Friday strengthens the language of those earlier reports with a warning that climate change may bring "abrupt and irreversible" impacts.

Such impacts could include the fast melting of glaciers and species extinctions.

Here's the NYT story.