Comments on: Urban vs. Rural Warming

By: Al Fin

Al Fin — Wed, 28 Nov 2007 22:26:55 +0000

The heat island effect is a strong distortion of surface temperature readings. The effect on satellite readings should be minimal and easily corrected. Wherever climate models use surface temperatures as parameters, they are skewed.

CO2 is a minimal, self-limiting forcing. Much stronger anthropogenic forcings include land use changes. The non-anthropogenic forcings blow everything else out of the water.

By: Bruce Hall

Bruce Hall — Wed, 28 Nov 2007 20:42:44 +0000

JT,

while there is the direct impact of being in the vicinity of heat producers, there is also the stored/augmented heat from concrete structures and asphalt paving, among others, that affect the urban [heat island] area but dissipate quickly beyond [certainly some mixing occurs, but heated air also rises and cools].

Perhaps you've heard the urban weather station expression, "Low tonight in the XXs; cooler in the outlying areas." There's a reason for that.

By: Roy Hammond

Roy Hammond — Wed, 28 Nov 2007 17:57:44 +0000

For some reason…whenever you talk of “heat islands”…the Atlanta region is always the best example that folks use. There is no doubt…with the massive cutting of trees over the past fifty years and massive use of asphalt and concrete…we’ve doubled-up the heat production of Atlanta and its 50-mile radius. I’d like to see a 20-year project where we plant a massive amount of trees in the region (state, private and nationally-funded)…to make the point that we could cool a “heat island”, if we really wanted to. The question comes up though…even if we cooled Atlanta by an average of four degrees over an entire summer…are we really accomplishing anything of real value…other than personal comfort?

By: Roy Hammond

Roy Hammond — Wed, 28 Nov 2007 17:57:40 +0000

By: Roy Hammond

Roy Hammond — Wed, 28 Nov 2007 17:57:29 +0000

By: jt

jt — Wed, 28 Nov 2007 12:39:21 +0000

"Heat islands" are tough to explain if you're measuring greenhouse effects (unless you belive the wind doesn't mix urban vs. rural air). It's more likely, I suspect, that we're seeing a good deal of *direct* heating from all kinds of urban combustion--heating, electrical generation, car engines, etc. Virtually all of the fuel that comes into a modern city is turned into BTUs that directly warm the local environment (a "campfire effect"?). In fact, even nuclear plants generate huge amounts of heat, which is dissapated through cooling towers or just pumped into local rivers.

Again, blindingly obvious: Fire is hot.

By: Bruce Hall

Bruce Hall — Wed, 28 Nov 2007 01:47:01 +0000

Not only is it blindingly obvious that the Urban Heat Island effect is responsible for recording higher minimum temperatures, it is also responsible for many weather stations that were previously well sited to become mini-urban heat islands as parking lots and buildings and air-conditioners encroach on those sites and significantly skew the temperatures being recorded… both higher lows and higher highs… and, presto, global warming!