Dr. Gunther will review the basic principles and observations that have led every scientific academy in the world to conclude that human emissions of greenhouse gases are altering planet Earth’s climate. He’ll also argue that this basic truth has been known since the 19th century and that a 21st century response is long overdue. What all this means for the United States in general and for the Bay Area in particular will be important parts of his presentation. Let Dr. Gunther and OLLI draw you into a much needed discussion. There’s a lot at stake.