W. STERK, H.-J. LUHMANN, F. MERSMANN| HOW MUCH IS 100 BILLION US DOLLARS 1. Introduction Climate finance is one of the core issues in the nego­tiations on a future climate regime. Developing coun­tries have called for the transfer of financial resources from industrialised countries to enable them to engage in mitigation and adaptation actions since the outset of the international climate negotiations at the beginning of the 1990s. The rationale is twofold. First, about three­quarters of the anthropogenic greenhouse gases(GHGs) that have accumulated in the atmosphere since the start of industrialisation were emitted by the industrialised countries. Hence, the industrialised countries are main­ly responsible for creating the climate problem. Second, the industrialised countries have a much greater econo­mic capacity for taking action than developing countries, most of which are still struggling to combat endemic po­verty, not least due to the legacy of colonial exploitation. Article 3 of the United Nations Framework Convention on Climate Change(UNFCCC) therefore commits in­dustrialised countries to take the lead in combating cli­mate change. As part of this leadership role, Article 4 of the UNFCCC and Article 11 of the Kyoto Protocol both mandate the Parties listed in Annex II of the Convention  1 to provide»new and additional« financial resources to developing countries to support capacity-building, de­velopment and transfer of technologies, mitigation of greenhouse gas(GHG) emissions, adaptation to the im­pacts of climate change, economic diversification and so on in developing countries(Articles 4.3, 4.4, 4.5 and 11 of the UNFCCC, Article 11 of the Kyoto Protocol). Despite these commitments, the actual amount of re­sources provided by industrialised countries so far has been relatively small. The 2010 World Development Report puts the climate finance currently provided by industrialised countries at around 10 billion US dollars annually(World Bank 2010). However, the environment for the negotiations has changed significantly in recent years. Annual – not cu­mulative – emissions of developing countries have now surpassed those of industrialised countries and are rising steadily. Strong mitigating actions on the part of devel­oping countries are therefore indispensable to prevent 1. These are essentially the member states of the Organisation for Econo­mic Cooperation and Development(OECD) as of 1992, the most wealthy among the industrialised countries. dangerous climate change, which puts developing coun­tries in a significantly stronger negotiating position than before. As a consequence, the Bali Action Plan adop­ted at the 2007 UN climate conference in Bali contains the provision of financial resources as one of the key building blocks of the future climate regime, and clearly conditions mitigation actions by developing countries on adequate financial support from industrialised coun­tries. While there are various negotiation items related to climate finance, they ultimately all relate to two main topics: mobilisation of the needed amount of financial resources and the institutional structure of funding. As for the mobilisation of resources, at the UN climate conference in Copenhagen the industrialised countries pledged up to 30 billion US dollars for fast-start finance over the period 2010–2012 and a long-term commit­ment to»mobilise« 100 billion US dollars per year by 2020»from a wide variety of sources, public and private, bilateral and multilateral, including alternative sources« (UNFCCC 2010). Although not stated explicitly in the text, one may assume that there is an implicit under­standing that funding after 2020 will also be at least 100 billion US dollars per year. There was also a gene­ral agreement in Copenhagen to establish a new fund. However, developing countries fear that financing will come from existing sources – for example, by relabeling official development assistance(ODA) – instead of being »new and additional«. To promote the finance discussion, UN Secretary-Gene­ral Ban Ki-moon in February 2010 established a High­level Advisory Group on Climate Change Financing (AGF). The AGF was chaired by Prime Minister Meles Zenawi of Ethiopia and Prime Minister Jens Stoltenberg of Norway and composed of eminent experts such as George Soros and Lord Nicholas Stern. The task of the AGF was to evaluate options with regard to how to mo­bilise the 100 billion US dollars pledged in the Copen­hagen Accord. The AGF published its report in Novem­ber 2010(United Nations 2010). The report concludes that mobilising 100 billion US dollars is»challenging but feasible«. It emphasises innovative public sources that could yield a double dividend in terms of mobilising funds and incentivising emission reductions, such as car­bon taxes and auctioning of emission allowances from emission trading systems. 2