A number of the University's centers of excellence focus on the challenges of sustainability. The Centre for Development and Environment (CDE) manages research programmes in the field of sustainable development, focusing on its particular areas of expertise in integrated regional development and natural resource management. The World Trade Institute (WTI) manages research, education, and outreach focused on global economic governance, including global sustainability policy. The Oeschger Centre for Climate Change Research (OCCR) is at the forefront of international research on climate science and policy, and its researchers have participated as co-chair, coordinating lead authors or lead authors in all the assessment reports so far published by the IPCC.