I met a woman from the Met Office today who pointed me in the direction of the UKCP09 climate projections for London:

http://ukcp09.defra.gov.uk/content/view/31/6/

The key messages for Islington are that temperatures will increase, summer rainfall will decrease, but winter rainfall will increase.

Looking internationally, the FCO released a map of the impact of a global temperature rise of 4 degrees in October:

http://www.actoncopenhagen.decc.gov.uk/en/ambition/evidence/4-degrees-map/

And the Met Office also has some information on the climate impacts on developing countries at:

http://www.metoffice.com/climatechange/guide/effects/security.html