10 Startling Climate Facts from 2009
Condensed by Native Village
The current carbon dioxide (CO2) levels in the atmosphere are about 390 ppm (parts per million). This is highest in at least the last 2,100,000,000 years.
Previous CO2 peaks were never more than 300 ppm over the past 800,000 years.
This concentration is rising around 2 ppm each year.
2000-2009 was the hottest decade on record. Eight of the hottest 10 years have occurred since 2000.
2009 is one of the 5 hottest years since 1850. It is predicted that 2010 will likely break the record.
While there was a bit more summer Arctic sea ice in 2009 than the record lows of 2007 and 2008, it remains far below normal levels.
The Arctic ice cover is now perilously thin and is vulnerable to further melting. This poses an increasing threat to Arctic wildlife including polar bears.
The Arctic summer could be ice-free by mid-century, not at the end of the century as previously thought.
The East Antarctica ice sheet has been shrinking. Researchers were surprised -- they only expected the West Antarctic ice sheet to shrink because the East Antarctic ice sheet is colder and more stable.
Climate changes are already observed in the U.S. and are projected to grow.
These changes include heavier rains, rising temperature, rising sea levels, rapidly retreating glaciers, thawing permafrost, longer ice-free seasons on earth's waters, earlier snowmelt, and changing river flows.
Even slight climate changes may trigger abrupt threats to ecosystems which may not adapt or be revived.This includes insect outbreaks, wildfire, and forest dieback.
Struggling ecosystems facing additional stresses will be threatened with the abrupt changes first.
An example of such an abrupt threat is the outbreak of spruce bark beetles throughout the western U.S. This is caused by warmer winters that allow more beetles to survive.
Most mid-Atlantic coastal wetlands from New York to North Carolina will be lost with a sea level rise of 1 meter or more.
If we do not reduce greenhouse gas emissions,some of California's main fruit and nut tree crops may no longer be economically viable.
In addition, the U.S. production of corn, soybeans and cotton could decrease as much as 82%.