While he is confident that progress will be made in isolated cases, the conservative Christian Democratic minister said the goal of the UN conference should be the implementation of non-binding promises made in December last year, he told broadcaster Deutschlandfunk.
Forest protection, technological cooperation and financing long-term climate protection measures in developing countries are among these promises, he said.
But the top priority remains limiting warming to an increase of two degrees Celsius, he added.
Success at the summit, which runs from November 29 to December 10, will depend on whether countries can reach concrete and binding decisions, Röttgen said.
Greenhouse gas emissions must also be cut by between 20 and 30 percent, he said, calling Germany a good example in this area.
Last year Röttgen blamed the United States and China after the failure of the Copenhagen climate conference.
The low point of the negotiations came, according to Röttgen, when China refused to accept a pledge by industrialised nations to reduce CO2 emissions by 80 percent by 2050. In Röttgen's opinion, China's priority was clearly not protecting the climate, but rather "obstruction."
Röttgen added that the political elites in the United States were incapable of winning over the majority of the people to protect the climate. Too many Americans simply want "cheap money, so they can consume, and are not interested in limiting their CO2 emissions," he said in an interview with news magazine Der Spiegel at the time.