This technical paper provides an update to the paper on investment and financial flows to address climate change which was published by the secretariat in 2007. This update was requested by the Ad Hoc Working Group on Long-term Cooperative Action under the Convention (AWG-LCA), at its second session, taking into account paragraph 1 of decision 1/CP.13 (the Bali Action Plan). The technical paper presents different options, tools and mechanisms to enhance financing for mitigation, adaptation and technology cooperation for an effective response to climate change. Further, the assessment of options, tools and mechanisms is enriched by information submitted by Parties and other observer organizations as part of the work of the AWG-LCA. It also presents relevant new information available on the investment and financial flows needed.