Gaian Variations is an oratorio that depicts Earth system science as one of the great revolutions in human thinking, yet also a direct outgrowth of the last two centuries of scientific development. There is little remaining dispute that James Lovelock and Lynn Margulis unleashed a vast revolution: as James Green, NASA's Director of Planetary Sciences, noted in 2010, "Dr. Lovelock and Dr. Margulis played a key role in the origins of what we now know as Earth system science." What Lovelock and Margulis preferred to called "Gaia" - the idea that our planet functions as a single self-regulating entity - remained highly controversial for decades, with prominent Neo-Darwinists like Richard Dawkins claiming that such self-regulation would be impossible and run counter to the laws of natural selection. In 2001 more than 1,000 scientists signed a Declaration under the aegis of the United Nations and four global bodies which states at its outset "The Earth System behaves as a single self-regulating system," largely ending debate about this core concept of Gaia. Even the most strident critic of Gaia theory, Toby Tyrrell, noted that this declaration highlights "the degree to which Gaia has been accepted by a large part of the scientific community."