In Bonn, Germany, a small mention in a massive UN scientific report about the need for deeper cuts in greenhouse gases by developed nations has become a major obstacle in reaching a new UN climate treaty. Developing nations at UN talks in Bonn are pushing for emissions cuts of 25 to 40 percent below 1990 levels by 2020, which they see as crucial for a successful agreement in Copenhagen in December. However, many developed nations argue that such reductions would harm their economies. Yvo de Boer, head of the UN Climate Change Secretariat, described the 25 to 40 percent range as a guiding principle for measuring the success of the Copenhagen talks. The range of 25-40 was derived from a few studies and was not included in the "summary for policymakers" of the IPCC report, which involved 2,500 experts. Shyam Saran, special climate envoy to Indian Prime Minister Manmohan Singh, noted that little progress has been made on setting targets during the Bonn talks. Developing nations like China and India believe that wealthy countries should aim for emissions cuts of at least 40 percent, citing worsening evidence of global warming since 2007. Additionally, small island states, facing the threat of rising sea levels, argue that rich nations should cut emissions by at least 45 percent below 1990 levels. Saran indicated that achieving a forty percent reduction by 2020 is a reasonable goal if the issue is as significant as believed. De Boer clarified that this percentage is not an agreed upon target, but rather a scenario to prevent the worst effects of global warming. Many developed countries, including the United States under President Barack Obama, believe this goal is unattainable. Obama aims to reduce U.S. emissions to 1990 levels by 2020, a 14 percent decrease from 2007 levels, and by 80 percent below by 2050. Japan recently set a 2020 target of just 8 percent below 1990 levels. Bill Hare from the Potsdam Institute for Climate Impact Research stated that achieving a 25 percent reduction is still possible but will be challenging. He stated that recent scientific discoveries had supported the range. The omission of the 25-40 percent from the summary was due more to technical issues than doubts about its accuracy. The 25 to 40 percent became widely known in political circles after being referenced on page 776 and other findings were included as a footnote to a document starting discussions on a new treaty at a meeting of over 190 nations in Bali in 2007. Currently, wealthy nations have proposed cuts ranging from 8 to 14 percent below 1990 levels by 2020, according to Hare. The European Union has offered cuts of 20 percent, or 30 percent if other developed nations also participate. And on page 776, it is stated that developing countries need to make a significant change by 2020 in order to slow down the increase in their emissions compared to the usual business practices. This decision divides wealthy and poorer nations into two distinct groups rather than implementing a graduated system of reductions with the wealthiest nations making the most significant cuts. Alden Meyer from the Union of Concerned Scientists mentioned that both sides believe they are being asked to do too much. It is uncertain how this impasse will be resolved. The wealthy countries may offer greater reductions or the poorer countries may compromise, potentially in exchange for clean technologies and increased aid. Hare mentioned that Russia, a major country that has not yet established a greenhouse gas target, could have a significant impact as its emissions are already approximately 30 percent lower than 1990 levels since the Soviet Union's collapse. Setting a 2020 goal for Russia to maintain current emission levels would further reduce overall promised cuts to between 12 and 18 percent. However, some countries argue that emissions reductions do not necessarily have to fall within this range, especially if future reductions are more substantial. Jonathan Pershing, leader of the US delegation in Bonn and an author for the IPCC chapter that included the 25-40 percent range, mentioned during a recent briefing that there are other potential trends to consider.