Mr. Christensen taught secondary level science in public schools for 32 years. Since 1968, he has pioneered the development of Environmental Science/Earth Systems Science which resulted in the publication of Global Science's success as a national curriculum. He now seeks to broaden the reach of that branch of science with the publication of Make Earth Sustainable Again: A Survivor's Manual for Life on Planet Earth. The target audience is the general public.

Mr. Christensen retired from the classroom in June, 1995. Since retirement, Mr. Christensen has conducted numerous Global Science teacher training workshops - each ranging from one hour to 5 days in length. Mr. Christensen's Global Science curriculum was selected by the National Science Teachers Association (NSTA) as one of our nation's exemplary science programs at the national level. The Global Science curriculum in now used throughout North America and in several countries in Europe, Asia, and the Middle East.

Two summers were spent on the writing team of NSTA's Project for an Energy Enriched Curriculum (PEEC). Five summers were spent at the University of Northern Colorado (UNC) on the staff of the National Science Foundation (NSF) supported teacher institutes which targeted academically uncommitted high school students. Mr. Christensen was on the writing team that produced Harvard Project Physics. He has both attended and taught at numerous National Science Foundation and Department of Energy funded teacher institutes across the nation.

Mr. Christensen's efforts in curriculum development have been supported and funded by private foundations, professional societies, the Colorado and National Endowment for the Humanities, and concerned individuals.