Global warming
Global warming, the phenomenon of increasing average air temperatures near the surface of Earth
over the past one to two centuries. Since the mid-20th century, climate
scientists have gathered detailed observations of various weather phenomena (such as temperature, precipitation, and storms) and of related influences on climate (such as ocean currents
and the atmosphere’s chemical composition). These data indicate that
Earth’s climate has changed over almost every conceivable timescale
since the beginning of geologic time and that, since at least the
beginning of the Industrial Revolution, the influence of human activities has been deeply woven into the very fabric of climate change.
