Negotiations went on through the night of 15 -16 Dece,ber following the approach proposed by COP15 President Connie Hedegaard, with developed and developing nations 'pairing up' in an attempt to find common ground. Unbridged gaps remain on the headline points: - in his press briefing on 15 December UN Secretary General Ban Ki-Moon referred to the push for a 'politically binding' agreement based on a target of limiting global temperature rises to 2 degrees. This echoed the EU position confirmed earlier in the day, and suggests that the only nod towards the 1.5 degree limit demanded by Africa and the Alliance of Small Island States (AOSIS) will be a broad aspirational statement that temperature rise should be kept 'within' 2 degrees. - Todd Stern, US chief negotiator, said that he did not anticipate any increase in the US commitment to emissions reduction targets, pointing out that both the targets and the 2005 base year are tied in with the Climate Change legislation currently pending in the Senate. Instead, the US is focusing its negotiating efforts on the funding of mitigation and adaptation measures in vulnerable developing economies. - the EU has so far held to its position that a 20 per cent reduction in emissions on 1990 levels might be increased to 30 per cent if other developed nations move to increase their targets. In this context 'other countries' mainly refers to the US and China. Critics of the EU's position point out that 30 per cent has been described by the delegation as the target required in principle. The decision to stick to a lower target unless others also move does not seem to have created the leverage that its authors anticipated. A unilateral move to 30 per cent target is likely to generate disputes among the EU's 27 member states. Already this year Poland, Hungary, the Czech Republic and Romania have objected to the imposition of targets and methodologies by the EU Commission, arguing that they would inhibit economic growth in those countries, which regard themselves as 'developing' economies. By contrast, an EU decision to stick to 20 per cent would unleash a storm of criticism, pointing out that it falls short of the 30 per cent figure identified by the EU delegation itself as the 'principled' position. To compound EU difficulties, NGOs continue to press for a 40 per cent target, arguing that 30 per cent is too weak. - since arriving in Copenhagen on 15 December UK Prime Minister Gordon Brown has argued for the establishment of a $100 billion annual fund to help developing countries with adaptation and a move towards renewable energy. Brown's proposal would be based on a global tax on financial transactions plus taxes on shipping and aviation. With the 'High Level Segment' of the summit now in full swing, the atmosphere at the Bella Centre has markedly altered. Security has been stepped up with the installation of airport style checks - 3 to get from the entrance to the media centre and over to the main press briefing room. NGO and Observer numbers have been strictly limited, and meetings curtailed as the government teams push to ensure that heads of state have something 'politically binding' to sign and congratulate themselves on by Friday night.