Greenpeace is calling on European Union and African leaders who met in Lisbon to take immediate action to prevent the destruction of African forests, which leads to carbon emissions that contribute to climate change. Stephan Van Praet, coordinator for the Greenpeace International Africa Forest Campaign, emphasized the importance of political leaders supporting a halt to deforestation in Africa. Trees absorb carbon dioxide while they grow and release it when they decompose or are burned, making deforestation a significant contributor to man-made carbon dioxide emissions. Urgent measures are needed to address this issue, as deforestation is responsible for a quarter of carbon dioxide emissions, equivalent to the output of the United States, the world's largest polluter. Greenpeace activists displayed a banner at Lisbon's Vasco da Gama tower calling for action to save African forests and the climate. Stephan Van Praet announced that Greenpeace's campaign in Lisbon would continue throughout the weekend. He emphasized the importance of Europe implementing laws to prevent illegal timber from entering its market to strengthen its credibility in the global fight against climate change and deforestation. Van Praet stressed that Europe must lead by example in order to be considered responsible in the international market. The EU has committed to reducing emissions to 20 percent below 1990 levels by 2020 to address the impacts of climate change such as heatwaves, disease, rising sea levels, and droughts.