Coyote Blog

I thought this was an interesting discussion of leap seconds.  At its heart, the debate is about a tradeoff between hassle (a lot of programming goes into inserting a second into a day every year or so) and how close we want time to match its traditional association with astronomical observations (e.g. noon is exactly noon at Greenwich).   This is a debate that has occured at least since the imposition of time zones (mainly at the behest of railroads) which for many cities converted "sun time" to "railroad time."  Until then, every town was on a different time with noon set to local astronomic noon.  Now, only a few cities actually have noon at noon.  Of course, daylight savings time took this even further.

For years I have said that daylight savings time likely made no sense as an energy saving program.  It was first used back in World War I, when electricity demand was primarily driven by illumination.  At that time, shifting the clock around to better match working hours with sunny hours (ie times with natural light) probably did save electricity.  But today, electricity demands are driven much more heating and cooling.  The same logic no longer holds.  In Arizona, the earlier the sun goes down, the less electricity we have to use when we are home in the evenings to keep the house cool.

It seems that research has confirmed my gut feel:

The result of the study showed that electricity use went up in the counties adopting daylight saving time in 2006, costing $8.6 million more in household electricity bills. The conclusion reached by Kotchen and Grant was that while the lighting costs were reduced in the afternoons by daylight saving, the greater heating costs in the mornings, and more use of air-conditioners on hot afternoons more than offset these savings. Kotchen said the results were more "clear and unambiguous" than results in any other paper he had presented.

Of course, daylight savings time will never go away, because modern environmentalism has become more a matter of making empty feel-good gestures than performing rational acts that actually improve something.

Why?  Because we don't have daylight savings time.  I have argued for years that DST may have made sense when electricity demand was driven by lighting, but air conditioning actually reverses the equation, putting people at home during more of the cooling hours.   The Liberty Papers links to a study with similar results:

Our main finding is that"”contrary to the policy's intent"”DST increases residential electricity demand. Estimates of the overall increase are approximately 1 percent, but we find that the effect is not constant throughout the DST period. DST causes the greatest increase in electricity consumption in the fall, when estimates range between 2 and 4 percent. These findings are consistent with simulation results that point to a tradeoff between reducing demand for lighting and increasing demand for heating and cooling. We estimate a cost of increased electricity bills to Indiana households of $9 million per year. We also estimate social costs of increased pollution emissions that range from $1.7 to $5.5 million per year. Finally, we argue that the effect is likely to be even stronger in other regions of the United States.

But its dry heat.

As a public service, Arizona is taking onto itself all the worldwide effects of global warming, thereby saving polar bears in Greenland and archipelago-living indigenous peoples.  Once it gets over about 108 you don't really notice the difference anyway.  Picture taken at 4:50PM MST today in the inappropriately-named (at least for today) Paradise Valley, AZ.  For all those who want to compare this to hell, I would remind you that the core of Dante's hell was frozen and cold, not hot.  Dante knew what he was talking about.  It may be hot but there is nothing to shovel off my driveway.

By the way, when people laugh at Arizona for not observing Daylight Savings Time, this is why we don't.  At nearly 5:00, we are hitting our peak temperature.  If we observed DST, we would not be hitting this peak until 6:00.  Temperatures here will cool over the next two hours by 20 degrees  (its already fallen nearly 3 degrees in the 20 minutes since I took the picture, and the sun is not down yet).  With this fast temperature drop typical of the desert combined with evening shade, it will be nice enough to be outside, eating or relaxing or watching a little league game by 7:00.  If I had my druthers, I would observe reverse daylight time, going back rather than forward an hour in the spring.  More observations on DST from myself and Virginia Postrel here.

Congress is probably going to extend Daylight Savings Time, despite complaints from airlines that their rescheduling and reprogramming costs will be exorbitant. Virginia Postrel points out that while a boon for the Northeast, southerners are not amused:

The source of this bright idea is, not surprisingly, the ever-meddlesome Ed Markey, who calls the bill
"a huge victory for sunshine lovers." As a certified sunshine lover, I'd say it
looks more like Massachusetts's revenge on Texas (and the rest of the Sunbelt)
for George Bush's victory over John Kerry. There are some places--and Dallas is
definitely one of them--that need just the opposite: shorter sunny evening
hours. Once the sun goes down and the temperature falls to the high 80s, you can
actually enjoy sitting outside.

The ostensible goal of the bill is energy saving, but the evidence
is weak.... 

Oddly missed even in fairly
thorough accounts is
any consideration of the extension's most obvious cost: More demand for
energy-eating air conditioning in the fast-growing, very hot Sunbelt. A lot more
people live down here than did back during the Nixon administration.

Southerners, come join Arizona on the "dark" side of this issue.  Arizona decided long ago that it had plenty of daylight, did not need to save it, and therefore was not going to play with the other kids.  We sometimes catch some grief for being out of step, but you don't see any of us scrambling around the house twice a year looking for our VCR manual to figure out how to change the clock.