Wednesday, December 23, 2009

Settled science?: If dark carbon causes 94 percent of Arctic warming, and if contrails account for another 15-20%, how much is caused by natural variability and trace amounts of CO2?

Yet Another Human Climate Warming Effect In The Arctic – Aircraft Contrails « Climate Science: Roger Pielke Sr. article in Scientific American by David Biello based on a study by Charlie Zender, a climate physicist at the University of California, Irvine stated
““…. on snow—even at concentrations below five parts per billion—such dark carbon triggers melting, and may be responsible for as much as 94 percent of Arctic warming”.
Now we have yet another human climate forcing that was reported by Rex Dalton of Nature News in the article

How aircraft emissions contribute to warming – Aviation contributes up to one-fifth of warming in some areas of the Arctic.

The article includes the text
“The first analysis of emissions from commercial airline flights shows that they are responsible for 4–8% of surface global warming since surface air temperature records began in 1850 — equivalent to a temperature increase of 0.03–0.06 °C overall.

The analysis, by atmospheric scientists at Stanford University in Palo Alto, California, also shows that in the Arctic, aircraft vapour trails produced 15–20% of warming.”


Anonymous said...

If contrails are up to twenty percent this begs the obvious question - What percentage are CHEMTRAILS? No, they are not the same thing.

John Marshall said...

94% warming is caused by dark carbon and 15-20% contrails wow! that is more than 100%.
Contrails could slow heat loss but they can also reflect solar radiation back into space so they must be of neutral effect!
Much of 'dark carbon' is from wildfire incidents so we must measure that from wild fires and that from fossil fuel use. This will be impossible.

Anonymous said...

Pielke... I really don't trust him. He can't seem to make up his mind and fluctuates on issues. No, he's in it to ride the waves, not to actually solve the problem (there is NO problem, minus REAL pollution... mercury, fluoride. plastics, etc.)