When I was out for a walk yesterday afternoon—comfortable in shirtsleeves with the November 6th temperature in Dummerston, Vermont rising to over 75°F—my mind turned to global warming. I was reminded of a news report some weeks earlier that 2015 would almost certainly break a temperature record globally.
I was curious about that, so went online last night. How could climate scientists be so confident in predicting that 2015 would be the warmest year on record, since we were only three-quarters through the year? What I found was both surprising and frightening.
The hottest years, month-by-month
The chart below is from the NOAA National Centers for Environmental Information (NCEI) website. On it are shown the six hottest years on record, globally—by month—along with the average temperatures for 2015, through September. The six warmest years in the chart, in order, are 1998, 2009, 2005, 2013, 2010, and 2014 (the current record-holder). Those lines are in color, while 2015 is the black line.
What is remarkable is that for every month this year, the average global temperature is well above the monthly temperature for those six-hottest years. It is striking just how much hotter 2015 is than those other six years. It’s easy to see how scientists could so confidently conclude that the annual average global temperature for 2015 will be a record.
Monthly deviations from the 1880-2015 average
I looked further on the NCEI website and came across another chart showing the top-ten months with the greatest departures in average global temperature, compared with the average for the period from 1880 to 2015. This chart is shown below. These anomalies range from 1.51°F to 1.62°F.
What is so striking in this chart is that of those ten months with the largest deviation from the long-term average, six of those months have occurred in 2015. Think about that. This data set includes global average monthly temperatures for 1,629 months, and of those six were this year—with three months still to go.
Will we call it global warming again?
Given the politics in the U.S., there has been a trend away from referring to “global warming.” We have opted to refer to “climate change” instead. This shift was made, I suspect, because every time there’s a cold spell climate change deniers would rush to the media claiming that global warming wasn’t happening.
Climate scientists argued, as they always have, that there is a lot of variation in temperatures and that, in fact, the climate models predict that changes in the global jet streams and ocean currents were expected to result in cooling in some places in some years. That could better be conveyed to a lay audience—especially one in which a significant percentage, as far as I can tell, doesn’t believe in dinosaurs—if the scientists referred to climate change rather than global warming.
But the global data emerging from 2015 makes me wonder if we will again begin referring to global warming.
The relevance to resilience
What all this tells me is that those of us focused on resilient design will have to ramp up our efforts to address heat waves and strategies for keeping people safe during summer months if disturbances—storms, tornadoes, wildfires, and such—cause power outages that prevent us from using air conditioning.
We have a lot of work to do!
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Along with founding the Resilient Design Institute in 2012, Alex is founder of BuildingGreen, Inc. To keep up with his latest articles and musings, you can sign up for his Twitter feed. To receive e-mail notices of new blogs, sign up at the top of the page.