Delegates from more than 180 countries meeting in the western German city are hammering out the details of a treaty to succeed the Kyoto Protocol, which runs out in 2012.
The Bonn meeting is the second of five negotiation rounds before national delegations are supposed to agree on a final deal at a conference in Copenhagen, Denmark, in December.
The groundwork of the Bonn talks is a draft document presented by the U.N. Framework Convention on Climate Change, the body organizing the meetings.
European negotiators are hopeful that the new negotiation team sent by U.S. President Barack Obama can instill the negotiations with fresh momentum. America has never ratified the Kyoto Protocol, and observers hope that Washington can now take over a leadership role.
"The political moment is right to reach an agreement," said UNFCCC Executive Secretary Yvo de Boer, according to German broadcaster Deutsche Welle. "There is no doubt in my mind that the Copenhagen climate conference in December is going to lead to a result. If the world has learned anything from the financial crisis, it is that global issues require a global response."
The draft text requires developed countries to reduce carbon emissions by 75 percent to 95 percent by 2050, measured against 1990 levels, and also sets concrete reduction targets for emerging economies including India and China.