Wednesday, August 15, 2012

Global warming, like politics, is local

Texas is unlike most of the world in many ways, but there is one way in which it seems similar.  On a warm spring day in March, when the temperature climbs to near 90 degrees, global warming seems to be the talk of the town.  Of course, 6 weeks earlier when the temperatures in Texas were an unseasonably cold 26 degrees, the typical reaction was to scoff at global warming.

The problem, of course, is that global warming reflects a rise in the average temperature across the globe over the span of years.  The rate of change overall is very slow.  But very few actual days sit on the average temperature.  Instead, there is a lot of variability from day-to-day.  During the winter in Texas, it is not uncommon to see temperatures rise or fall 40 degrees in a day.  

These kinds of anecdotes are fun, but is there really any truth to the idea that people’s belief in global warming is affected by the temperature that day?  This question was explored in a paper by Ye Li, Eric Johnson, and Lisa Zaval in the April, 2011 issue of Psychological Science.

In one study, participants were people in the US and Australia (where it was summer in the northern hemisphere and winter in the southern hemisphere).  People rated the strength of their belief in global warming.  They also rated whether they thought the temperature that day was warmer, colder, or about normal for that time of year.  When people felt the day was warmer than usual, they also expressed a higher belief in global warming than when they felt the day was cooler than usual. They also expressed more concern for global warming when the day was warmer than usual rather than cooler than usual.  The order in which people were asked about global warming and the day’s temperature did not affect the ratings.

Does this really matter for people’s behavior?

In a second study, another group of people performed an internet study for which they were going to be paid for their participation.  Along the way, they answered the same questions about global warming and the day’s temperature.  At the end of the study, participants were asked to donate as much of their payment for the study as they desired to a charity that focuses on cleaner air and prevention of global warming.  The participants in this study donated over four times as much money when the day was much warmer than usual than when the day was much cooler than usual. 

These data really highlight why it is so hard to create policies to deal with long-term problems like global warming.  At a conceptual level, it is easy to make arguments about the importance of many problems like global warming, hunger, and human rights.  However, our behavior is influenced most strongly by our local conditions.  Unless these abstract world problems can be turned into specific issues that affect our world right now, we are unlikely to do much about them.

Unfortunately, for many problems like global warming, by the time we really feel their effects, it will be too late to do anything about them.