Did you know that?
1.
Earth is actually closer to Sun during winter in
the U.S. than during summer.
2.
Humid air (i.e., air with water vapor in it) is
less dense than dry air.
3.
Deserts can get really, really cold at night.
4.
The Sun is still there even when it's night.
These are all facts that many may find counterintuitive.
This week an extraordinarily rare storm brought snow to parts of the Middle
East, including Egypt. I tweeted (@DrShepherd2013) an amazing picture of snow
on the Sphinx that was shared from a credible colleague's page. However, it is now believed to be a fake picture though the snow event is real (http://www.buzzfeed.com/michaelrusch/heres-definitive-proof-the-photos-of-the-sphinx-covered-in-s). Internet hoaxes take all of us at times. Winter weather did happen in the region though. Matt Daniel (EarthSky) does a nice job explaining the "meteorology" of what happened at http://earthsky.org/earth/rare-snow-storm-hits-middle-east.
Inevitably, you started hearing statements challenging
climate change based on this singular event. Like the 4 facts above, many find
it challenging to think of a warming climate and cold, snow events.
However,
the following points are worth noting:
1 “Weather is your mood, climate is your
personality”-On a given day, week or season, cold or wintry weather signifies
nothing about the background climate changing. If a Major League Baseball
pitcher (typically not known to have high batting averages) hits 4 homeruns in
a game, do I draw a conclusion that he is going to break the MLB Home Run
record. Probably Not! Congressman Jared Huffman said it best in a recent House
Floor Speech (google for his 1-2 minute remarks on You Tube)-“ The fact that
it is snowing simply means that it’s snowing”. He also correctly notes that
winter happens every year, and it still will in 2080.
Many see things in a very “straight line” in
terms of a sequence of events (i.e., linearity). Legendary meteorologist and
mathematician, Ed Lorenz, reminded us decades ago that the atmosphere (i.e.,
weather and climate) is not linear. As
such, when someone makes a statement about climate change based on a cold
day/week or snowstorm in Egypt, it sends a calling card on their background in
atmospheric sciences and understanding of the non-linearity of the atmosphere.
Any properly trained meteorologist knows that (a.) cold/warm events are
influenced by wave patterns in the atmosphere, jet streams, and other processes
(e.g., think of pushing down one part of a kid’s inflateable- one area goes
down, another area rises), (b.) El Ninos and Arctic Oscillations play a role in
weather, and (c.) a warmer atmosphere holds more water vapor. These things play out within a larger climate
system that is likely changing too. I am
certain the story at this link (http://www.usatoday.com/story/weather/2013/02/18/climate-contradiction-less-snow-more-blizzards/1927893)
is very counterintuitive to many because it makes the case that a warming
climate can actually bring stronger blizzards.
I am not suggesting this research is conclusive (far from it in fact), and I am certainly not
making any links between the Egypt snow and climate change. My point here is
that oversimplification of “cold”
weather and “warm” climate is an error and the reason meteorologists have to
take calculus and differential equations and not just algebra.
If all else fails, consider what Ret. Admiral Dr. David
Titley, Professor of Meteorology and Director, Center for Solutions to Weather
and Climate Risk said when asked about the snow in the Middle East, “Climate is
the 'deck' from which the weather is dealt -- weather is the hand you play
today. Still possible to get a hand full of low cards even if there are more
Aces in the deck...”
And just for the sake of reminder that I try to be objective on these topics, I wrote a cautionary blog after Typhoon Haiyan noting care in making assertions about singular events and causation too.(http://haiyanandclimate.blogspot.com/2013/11/i-cant-say-haiyan-was-caused-by-climate.html).
And just for the sake of reminder that I try to be objective on these topics, I wrote a cautionary blog after Typhoon Haiyan noting care in making assertions about singular events and causation too.(http://haiyanandclimate.blogspot.com/2013/11/i-cant-say-haiyan-was-caused-by-climate.html).
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