U.N. Secretary-General Ban Ki-moon is in Boulder and Denver to address college graduates and scientists studying climate change.
The secretary-general is scheduled to receive an honorary degree from the University of Denver before addressing graduate students.
He's also visiting Boulder's National Center for Atmospheric Research.
When the secretary-general was here two years ago, he received an award from the University of Denver and also visited the Energy Department's National Renewable Energy Laboratory in Golden.
Observers will be watching to see if the secretary-general says anything about the search for chemical weapons in Syria. The Obama administration has said it doesn't want to get plunged into conflict there, but won't abide the ordering of chemical warfare.