Kit Batten. “The Lessons of Bali: The U.S. Needs to Lead on Global Warming”. Center for American Progress. December 18, 2007 – Developing nations, of course, must also work to reduce their greenhouse gas emissions, but they are far less responsible for the high levels of emissions currently in our atmosphere or the effects that global warming has already inflicted on the planet. For instance, the United States contributed an estimated 30 percent of the atmospheric greenhouse gases emitted between 1850 and 2003. As such, developed nations have a moral responsibility to make deep cuts in their emissions and help developing nations avoid developing along carbon intensive pathways.