Unexpected Changes in Earth's Climate Observed on the Dark Side of the Moon
Scientists who monitor Earth's reflectance by measuring the moon's "earthshine" have observed unexpectedly large climate fluctuations during the past two decades. By combining eight years of earthshine data with nearly twenty years of partially overlapping satellite cloud data, they have found a gradual decline in Earth's reflectance that became sharper in the last part of the 1990s, perhaps associated with the accelerated global warming in recent years. Surprisingly, the declining reflectance reversed completely in the past three years. Such changes, which are not understood, seem to be a natural variability of Earth's clouds.