Yvo de Boer, head of the UN Climate Change Secretariat, stated that despite the global financial turmoil, a new world climate deal should not be hindered as high energy prices continue to incentivize improvements in energy efficiency. De Boer emphasized that the current credit crisis is not having a larger impact on the global economy than current oil prices. However, he acknowledged that the uncertainty and lack of trust in financial markets are obstacles to developing green energy projects, even with oil prices around $100 a barrel. De Boer believes that lack of capital is not the main issue despite the current situation. Investment uncertainty is causing concern, and clear government action on climate change could help reduce this uncertainty. For example, if a company is planning to build a 500 million euro power plant but is unsure of their government's greenhouse gas emissions targets, it creates a risky situation. Despite some analysts' doubts, De Boer is optimistic about the United States joining a new global warming agreement in Copenhagen in December 2009. He believes it is possible for the US to sign up to the agreement. De Boer stated that the reasons for Washington's refusal to ratify the Kyoto Protocol in 1997, such as concerns about potential harm to the U.S. economy and the absence of emission reduction targets for developing countries, remain just as relevant today. The Kyoto Protocol requires 37 industrialized nations to reduce greenhouse gas emissions by an average of 5 percent below 1990 levels by 2008-2012, with no obligations for developing countries. In order to persuade the United States, now surpassed by China as the top emitter of greenhouse gases, the United Nations must involve developing countries. De Boer emphasized the need to protect their economic growth and minimize the costs of ambitious climate policies in order to achieve this. The Clean Development Mechanism (CDM) is a method used to attract developing countries by allowing industrialized countries to increase their emission quota if they invest in clean energy technology in developing economies. The debate within U.N. talks revolves around whether the CDM should encompass coal power plants that have the ability to store carbon dioxide. De Boer believes that carbon capture and storage would be crucial for coal-based economies like China and India, and suggests storing CO2 underground in locations such as empty gas fields. De Boer is optimistic that the upcoming talks in Poznan could lead to a new agreement in Copenhagen to replace the Kyoto Protocol, despite doubts from many.