Written by Kelly Herbst, Astronomy Curator for the Virginia Living Museum. Updated every two weeks, more or less.

Thursday, February 13, 2014

It's A Hoax!

*gasp*  You'll never guess why I missed that last blog post!  Aliens!  They abducted me and took me away to their secret lair somewhere in North America and performed experiments on me!  I can't believe I made it out alive!
This is SOOOOO NOT what happened.  Image from the vast internets.

Okay, that's not what happened.  But after being gone for a month, I figured I owed you a good one.

What really happened is far more mundane, but does lead to an interesting point.  Actually, two things kept me away from the computer for an extended period of time.  Thing number one: the various and sundry snowpocalypse (snowmageddon?) events taking place here in Virginia over the past couple of weeks.

January saw not only the so-called Polar Vortex come through our area, but another round of even deeper snow as well.  And yesterday a weird, sloppy, wintry mess cascaded over again, sending me home early before I could log in to write.  Three snow events in the space of a month in what is usually a maybe-one-good-snowfall-a-year kind of area.  What gives?

Many people claim that the existence of such wintry weather completely negates the idea of global warming.  Not fact, the weirdness and intensity of the weather we're seeing is, in fact, evidence of changes to our global climate.  See, there's the difference.  There's weather - whatever is going on now in the atmosphere - and there's climate - what the environment is like over a wide area averaged over time.  Weather and climate are not the same thing.  Just because the climate of a desert is warm and dry does not mean it never rains there.
A graph showing the departure from a standard global temperature averaged over one year (blue data) and averaged over 5 years (red line).  Such graphs are not always clear in what they are trying to tell us about our global climate.  This one, in fact, comes from a group attempting to deny the existence of climate change.  Image from New Scientist.

Global climate change is a real thing, and it existed long before humans came along.  The climate of the Earth has changed dramatically over the millennia of our planet's existence.  Glacial periods dominated by very cool global temperatures and expanses of ice covering much of the planet, followed by warm interglacial periods where, at some times, even the poles lacked major ice coverage.  Change will happen, whether we contribute to it or not.  But contribute to it we do, also whether we like it or not.  Simply by existing on the surface of the planet, life contributes to the Earth's ever-changing climate.

But we humans are getting good at changing things rapidly without being exactly sure of what we're doing.  No reputable scientist disputes the idea of human-driven change to the global climate - the evidence for it is too strong.  No, the real question is, have we set in motion something that will end up biting us in the tail?  Will the climate change so much, so fast, that we humans won't be able to adapt?  The planet will be fine - it has dealt with great changes before.  But can we?

The unsettled weather we are seeing is likely being at least somewhat driven by the average rise in global temperatures in the past many years.  Raising the temperature of something adds energy to it.  When there's more energy in the atmosphere, that energy is going move things around in different, more extreme ways - including in wintry ways. Just because the weather is cold doesn't mean global warming isn't real.  If you want more detail on why scientists know that global climate change is real, check out Phil Plait's wonderful blog, Bad Astronomy.  He's a wealth of information on the subject.

The other thing that kept me from writing was a nasty cold I picked up that migrated down into my lungs and became bronchitis.  And this even after I got my flu shot.  Why?  Because the virus that causes the flu and the virus (or possibly even bacteria, in the case of the bronchial infection) that causes colds are not the same.  We can vaccinate against the flu...but the rhinoviruses that cause colds...not so much.  And no, I'm in no danger from the flu vaccine itself.  Vaccines are quite safe, and there's no credible link between vaccines and autism.  Again, Phil Plait can point you towards tons of evidence that says yes, you should get your flu shot.

Well, now that I'm finally mostly better and the winter weather is at least somewhat abated, I need to get back to work.  I've got to go move Jimmy Hoffa from under the planetarium projector, and I really wish I could remember where I put that flag I got from the set where they filmed the moon landings...

Just kidding.

Back again in two weeks (assuming we're not buried in a snowtastrophe)...
Carpe noctem!