Agence France-Presse: Senator John Kerry has pledged to complete a framework of an elusive US climate change deal in time for next month’s high-stakes summit in Copenhagen, vowing not to let the world down. President Barack Obama’s election returned the United States to active global efforts to fight climate change, but a year later Congress has yet to make good on promises to set the first-ever US caps on carbon emissions. After a lobbying mission in the US Capitol by UN chief Ban Ki-moon, Kerry …