I shall present and explain the thesis that mankind is on the threshold of a dramatic transition: From an earth, predominantly powered by oil and other fossil fuels, with unsustainable global warming, to a new earth predominantly powered by "clean" solar and wind energy with greatly reduced global warming. A common choice for the transition point is "peak oil", when global oil-production peaks and begins to decline. I suggest that "peak-oil per capita" is more useful. While "peak-oil" may be 15 or more years in the future, "peak-oil per capita" is practically upon us because of the still rapidly rising world population. My best estimate is 2015 with an uncertainly of a few years. I shall discuss the great urgency for preparing as best as possible for this impending global transformation.