A widely agreed international target to avoid dangerous global warming must take account of local impacts and may need to change, said the chief scientist at the MetOffice Hadley Center, Britain’s biggest climate research center.

Julia Slingo said the target of limiting global temperature rise to 2 degrees Celsius (2C) may need adjusting to take into account research into local and regional effects, particularly on rainfall patterns, as climate science advances.

More than 120 nations agreed to the U.N.’s Copenhagen Accord last December which aimed to limit average global warming to less than 2C, in one of the main outcomes of a fractious summit.