The World Trade Organization together with the United Nations Environment Programme launched a study today into the interplay of trade and climate change, dpa reported. While stating that an increase in free trade could lead to greater emissions of carbon dioxide, which causes climate change, the report said trade could also be helpful in alleviating global warming. WTO Director General Pascal Lamy and UNEP Executive Director Achim Steiner in a statement called on the international community to seal a solid agreement at the UN climate convention in Copenhagen in December, as well as to conclude the Doha trade round which includes opening trade in environmental goods and services. "With a challenge of this magnitude, multilateral cooperation is crucial and a successful conclusion to the ongoing climate change negotiations is the first step to achieving sustainable development for future generations," WTO Director General Pascal Lamy and UNEP Executive Director Achim Steiner said in a statement.