Abrupt Climate Change, Richard
B. Alley, Scientific American, 291:5, (November, 2004).
Winter temperatures plummeting six degrees Celsius (a lot) and
sudden droughts scorching farmland around the globe are not just the stuff of
scary movies. Such striking climate jumps have happened before--sometimes within
a matter of years.
Global warming should be more of a worry than
ever: it could be pushing the earth's climate faster toward sudden shifts, because
it appears likely that humans are pushing certain aspects of climate closer
to the thresholds that could unleash sudden changes.
What does that mean in plain speaking terms?
- damaging tornadoes, cyclones, winter storms and hurricanes due to wind,
- prolonged evaporation of water bodies of especially smaller mass,
- briefer periods during winter of dormancy for plants,animals, and fungi,
- disruption of the budding, flowering and simultaneously necessary hatching of new animal life,
- serious floods, such as witnessed in Pakistan, Haiti, Central America, and the Cumberland River in the last decade,
- drought that lasts longer than historic droughts,
- fires accompanying a loss of soil moisture and cooler weather,
- less snow in places accustomed to accumulation and endurance of the cold pack (albedo and insulation is altered),
- Intense and sudden downpours of rain, sleet, hail, ice or snow.
What is abrupt climate change?
Evidence for climate chaos is growing.