"The time to find global solutions is running out. We can find adequate solutions only if we act together and unanimously," he said in a written message to Manuel Pulgar-Vidal, Peru's minister of the environment and host president of the 20th UN Climate Change Conference.
Thousands of negotiators from 195 countries gathered for the meeting in Lima Dec. 1-12 to hammer out details of a new international agreement to reduce emissions of greenhouse gases that cause global warming.
The Vatican released a copy of the Pope's message Dec. 11.
The Pope encouraged the leaders in their discussions because their instant decisions will "affect all of humanity, especially the poorest and future generations. What's more, it represents a serious ethical and moral responsibility."
The impact climate change already has been having on coastal regions and other areas "reminds us of the seriousness of negligence and inaction," he said. It is morally imperative that people act.
"An effective fight against global warming will be possible only with a collective and responsible answer" that overcomes one-sided or special interests and is "free from political and economic influence," he said.
The Pope said the leaders' response will have to "overcome distrust; promote a culture of solidarity, encounter and dialogue; and be capable of showing responsibility for protecting the planet and the human family."