The UN climate talks began in Poland with calls for immediate action against global warming despite economic challenges, and a warning that failure to act could lead to water shortages for half the world by 2050. US President-elect Barack Obama was praised for his ambitious goals in fighting climate change. Polish Prime Minister Donald Tusk emphasized the importance of environmental efforts regardless of economic conditions, stressing that financial crises are temporary but climate change is a long-term issue. The talks in Poznan mark the halfway point in a two-year process to reach a new climate treaty by the end of 2009 to replace the Kyoto Protocol. Danish Prime Minister Anders Fogh Rasmussen emphasized the importance of not allowing the financial crisis to deter efforts towards addressing urgent issues such as climate change. He will be hosting a meeting in Copenhagen in late 2009 to reach a UN deal. Rajendra Pachauri, the head of the UN Climate Panel, warned that many people were still not fully aware of the potential risks of "irreversible change" if the world does not take action. For example, he highlighted that the number of people facing water stress in river valleys could increase from 1.1 billion in 1995 to 4.3 billion in 2050, affecting a significant portion of the global population. Additionally, there is a concern that the Greenland icecap could melt, and an increasing number of animal and plant species are facing the threat of extinction. Yvo de Boer, the leader of the UN Climate Change Secretariat, emphasized the urgency of accelerating efforts to reach a deal by the following year. He stressed that time is running out and work needs to intensify. The WWF distributed walnuts to delegates at the conference venue, encouraging them to solve the climate crisis. Greenpeace revealed a large sculpture depicting the planet in danger from a wave of wood and coal. Rasmussen commended President Obama's initiatives following disagreements with former President George W. Bush. He expressed his pleasure in Obama's ambitious climate and energy policies as a way to address the economic downturn. De Boer also referred to Obama's plans as "ambitious." Obama aims to reduce US greenhouse gas emissions to 1990 levels by 2020, which are currently 14 percent higher than 1990 levels mainly due to fossil fuel burning. In contrast, Bush's policies do not anticipate a peak until 2025. In Europe, the economic downturn has raised concerns about the expenses associated with the EU's target of reducing greenhouse gas emissions by 20 percent from 1990 levels by 2020. Poland and Italy, both heavily reliant on coal for electricity generation, are spearheading efforts to negotiate concessions in a proposed agreement set to be finalized at a summit of EU leaders in Brussels on December 11-12.