Snapshot of Climate Change Science
A snapshot of climate change science:
_In the atmosphere, carbon dioxide and other ``greenhouse″ gases, mostly produced by burning coal, oil and gas, allow sunlight through but retain infrared radiation Earth emits back toward space.
_Since the Industrial Revolution began, carbon dioxide concentration in the atmosphere has risen from 280 parts per million to 358.
_Since the late 1800s, mean global temperature has risen between 0.3 degrees and 0.6 degrees Celsius (one-half and 1 degree Fahrenheit). Oceans, which expand when warmed, rose up to 10 inches.
_Computer models project further temperature increases of between 1 and 3.5 degrees Celsius (2 to 6 degrees Fahrenheit) by 2100, possibly the most abrupt climate change in thousands of years.
_The precise ratio of past warming attributable to man-made emissions and natural causes.
_The precise magnitude of warming that will result from given levels of atmospheric gases.
_The role clouds and oceans may play in mitigating _ or aggravating _ warming.
_Future population and economic growth, which affect emission levels.
_Future technological and lifestyle changes that may affect emissions.