¥Past 200 years human activities via fossil fuel consumption and
land-use changes have increased
all greenhouse gases ->+ ~0.8¡C (1.4¡F)
¥
¥CO2 once in atmosphere causes climate change
for ~1000 years (retention time)
¥
¥Key example of positive feedback-> +1¡C (1.8¡F) change in
atmospheric temperature caused by CO2 will stimulate water vapor
increase causing another +1¡C (1.8¡F) temperature increase (positive
feedback)
¥
¥Some aerosols (solid-vapor or liquid droplets-vapor mixture) in
atmosphere and some clouds scatter
sunlight offsetting warming to some degree, not all aerosols and not all clouds scatter sunlight
(or equally scatter)
¥
¥Currently cars, trucks and buses are the greatest contributors to
atmospheric warming
¥
¥34 billion tons of carbon dioxide released into atmosphere
annually from industrialization
and deforestation