"From the time the European invaders of North America established themselves and began keeping records, the bitter winters of the Little Ice Age become part of written history.From that point also, the natural history of northern North America began to deviate from its “natural” course. The continent was no longer isolated. The foreign invaders multiplied rapidly, destroying native ecosystems at an ever increasing rate. In time, the byproducts of technology began to poison earth, water, and air and have now begun to influence the climate. The measured responses of biosphere to climate, and of climate to astronomical controls have, for the foreseeable future, come to an end."