Fri July 20, 2012
Hot June Explained by State Climatologist Robert Gillies
June 2012 was the 4th warmest on record for the globe according to an analysis by the NOAA National Climatic Data Center. Warmer than normal temperatures were especially prevalent across the Northern Hemisphere, which, when analyzed separately, were the warmest June since records began in 1880.
UPR's Mackenzie Hamilton sat down with State Climatologist Dr. Robert Gillies to try to understand exactly what these June records say about the state of the climate here in Utah and around the world, starting by asking the obvious...
Is this caused by climate change?
"Climate scientists are frequently asked about an event such as these record-breaking temperatures. They're asked is it caused by climate change? The answer is of course that no events are caused by climate change, or for that matter, global warming. But all events have a contribution. It's an interconnected system. All weather events are affected by climate change because the environment in which they occur is warmer and moister. In other words, if we look at NASA and NOAA's data from the 1980s onwards, we see a steep incline in the global temperature (average temperature over the whole planet). In general the temperatures are increasing and that's manifest through regional areas as well because weather is a redistribution of energy."
Here in Utah, last summer it was floods and this summer it's fire. Should we be concerned about how quickly things changed?
"The interesting thing about the West is that climate (remember climate is statistics over time) is highly variable here in the West and that's very different than the East of the U.S. In one year we could have a lot of precipitation and the next year very little. That's within the realm of the climate. What's interesting is that temperature records this year are being broken all over the world. In fact I just heard yesterday that in Athens, Greece, the temperature reached 108, which is pretty dramatic. they had to shut the acropolis down. One blogger cheekily blogged that the marble of the acropolis is melting, which is a far stretch but still it was a significant temperature extreme. Of course we've been seeing temperature extremes here in Logan and in many other cities around Utah. Presently, we're breaking high temperature records much more frequently than you would expect would occur due to chance. Some climatologists have put a figure on this. They've come up with estimates that the ratio of the exceedence of breaking highs compared to what you expect by chance would lead them to say that there is about an 80% chance that the record high that you have experienced in your location is due to climate change global warming. That is quite sobering, I think."
"What has changed dramatically is the ratio of snow to rain. More is coming as rain than snow. You're getting a warmer atmosphere which is affecting the snow pack in two ways. One is that it's leading to a earlier melt off and its also leading to a faster melt off. that's why people perceive the snow pack as declining. In reality the amount of snow we're getting is roughly what we've been getting in the last 60 years. This water year's precipitation, down by about 70%, is still slightly above what it was in 2002. Our perceptions are short lived given the variability that we see lots of snow last year, not so much this year."
So this isn't a doomsday scenario?
"It depends where you are. If you're living in Bangladesh or Nepal things are going to be very different than here in the U.S. where, excuse the pun, we can weather climate change better than they can. What is important to realize is that the hydroclimate dynamics of snow to rain and how quickly snow melts and where it melts. And given that you're getting more rain and more flood events, how do you then alter your capture of water for future generations?"