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Earth Science

Cities' Heat Can Affect Temperatures 1000+ Miles Away 263

Posted by timothy
from the let's-terraform-earth dept.
Living in dense cities makes for certain efficiencies: being able to walk or take mass transit to work, living in buildings with (at least potentially) efficient HVAC systems, and more. That's why cities have been lauded in recent years for their (relatively) low environmental impact. But it seems at least one aspect of city life has an environmental effect felt at extreme distances from the cities themselves: waste heat. All those tightly packed sources of heat, from cars to banks of AC units, result in temperature changes not just directly (and locally) but by affecting weather systems surrounding the source city. From the article: "The released heat is changing temperatures in areas more than 1,000 miles away (1609 kilometers). It is warming parts of North America by about 1 degree Fahrenheit (0.6 degrees Celsius) and northern Asia by as much as 1.8 degrees Fahrenheit (1 degree Celsius), while cooling areas of Europe by a similar amount, scientists report in the journal Nature Climate Change. The released heat (dubbed waste heat), it seems, is changing atmospheric circulation, including jet streams — powerful narrow currents of wind that blow from west to east and north to south in the upper atmosphere. This impact on regional temperatures may explain a climate puzzle of sorts: why some areas are having warmer winters than predicted by climate models, the researchers said. In turn, the results suggest this phenomenon should be accounted for in models forecasting global warming."
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Cities' Heat Can Affect Temperatures 1000+ Miles Away

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  • by CRCulver (715279) <crculver@christopherculver.com> on Monday January 28, 2013 @04:43AM (#42713493) Homepage

    One of the concepts that interested me in Larry Niven's classic science-fiction work Ringworld [amazon.com] is a civilization having to move its planet out from its sun in order to avoid perishing in their waste heat. I haven't seen that possibility explored so much in the years since. With studies like this, along with Kurzweil-ish woo-woo of extrapolating growth, can we talk an amusing guess at how long until heat waste renders the Earth, or at least certain parts of it uninhabitable?

  • by AliasMarlowe (1042386) on Monday January 28, 2013 @04:55AM (#42713539) Journal

    more than 1,000 miles away (1609 kilometers)

    Seriously, if you have one rough rounded number you can't do an exact convert and add false precision to the statement...

    At least they didn't quibble about the difference between the UK Statute mile and the US Survey mile (the US mile is longer by 3.2mm [unc.edu]), or even the rounding error of over a third of a km in their conversion.

  • by sciencewatcher (1699186) on Monday January 28, 2013 @04:59AM (#42713545)
    Serious, first thing to look for a thermal is the local town, absent mountains or hills. A large parking lot already does do fine. I know of a military airport which has a cemetary nearby, the dense black marble is sufficient.
  • by Genda (560240) <mariet AT got DOT net> on Monday January 28, 2013 @05:06AM (#42713561) Journal

    I took chemistry a long time ago. The teacher said if you turn in dissociation constants with more than two decimal places, he'd mark them wrong (for those students who did their calculations on digital devices and copied all 10 digits of result.) He explained that these were chaotic events and everything past the second digit was noise.

    I think the point of the very specific number above is simply it being a single data point. In fact heat effects may travel tremendously further than even that. More important, if heat is shifting the jet stream, secondary and tertiary effects may be happening downstream many thousands of miles and include drought, flood, or unseasonable weather. As well, the city heat drives low altitude moisture and chemical particulates (soot and industrial dust) into the higher atmosphere (potentially punching a hole in the common inversion layers) and that moisture/nucleation may have significant down wind impacts as well. I'm looking forward to seeing what the models say. If we're lucky, the effect will be more cloud cover, increasing earth's albido, and be a thermal cooling factor over-all. If not, it may be adding to a climate that is growing ever more unstable and that's bad news for everyone.

    My question is, why isn't anyone talking about the air pollution problems happening this month in China? Air that's being called lethal by some, over 40x more polluted that world health limits recommend. Here's a story [freerepublic.com] about a factory that burned for 3 hours because nobody could tell the difference between the smoke and the pall of smog. My greatest concern is that over the last ten years there have been several events of smog from China reaching the western U.S., this being the worst smog event in remembrance, there is a real chance it could make it to America. Thankfully, it winter and most likely will be washed into the sea by storm systems. Had this been summer we would certainly be facing serious environmental threat. So why isn't this a HUGE conversation right now, virtually nobody is even talking about it.

  • by CaptainOfSpray (1229754) on Monday January 28, 2013 @05:08AM (#42713577)
    I've seen a map of thunderstorm frequency for UK which shows that a majority occur directly downwind (in prevailing wind direction) from cities, and size and frequency of storms is related to size of the city. Thunderstorm frequency and severity also relate to frequency and severity of lightning damage and hailstorms. If I can find that again, I'll post a link (unless someone else gets there first).
  • by icebike (68054) on Monday January 28, 2013 @05:28AM (#42713629)

    That's not the only downwind effect than can be attributed to human activity.
    Science News had an article on down wind rainfall being affected by large scale irrigation projects in California.

    http://www.sciencenews.org/view/generic/id/347691/description/Watering_fields_in_California_boosts_rainfall_in_Southwest [sciencenews.org]

    I wonder how long it will take for someone to research downwind effects of some of the huge wind farms that have been built. Taking that much energy out of the atmosphere should theoretically have an effect that might be measurable.

  • by viperidaenz (2515578) on Monday January 28, 2013 @05:32AM (#42713657)

    Also the vast majority of CO2 production is not man-made. The carbon cycle is massive. We just tipped the balance it was in by chopping down some carbon sinks and burning up some reserves.

  • by Rockoon (1252108) on Monday January 28, 2013 @08:27AM (#42714185)

    Isn't this comment more or less an archetypal example? Veiled and nonspecific allusions to error, uncertainty, and weakness?

    When the comment is about the veiled and nonspecific "scientific process" of climate science, then no.. its not an archetypal example.

    Science is a process. Are climate scientists following the process all the way through? The answer is that no, they are not, and certainly they cannot be blamed for not doing so because they dont have an atmosphere to perform tests upon.

    But the lack of blame in no way elevates the process that they do accomplish to a level above what it actually is. The parts of the scientific process that they cannot do are important, and the lack of doing important things is in itself important too. The claim "its science" doesnt carry as much weight when its not the complete method, and you should be ashamed of yourself for not knowing that.

  • by pubwvj (1045960) on Monday January 28, 2013 @01:30PM (#42716825) Homepage

    "Living in dense cities makes for certain efficiencies: being able to walk or take mass transit to work, living in buildings with (at least potentially) efficient HVAC systems, and more."

    None of these are valid justifications for cities.

    Transportation: I can and do walk, rarely needing a vehicle. No need for mass transport either. I live on a farm and work there as well as in the forest. No need to drive. I often go months without getting in a car or truck.

    Efficient HVAC: Our high thermal mass, well insulated home is far more efficient requiring far less energy for heating than city buildings and it requires no cooling. It also doesn't affect the local or distant environments.

    Cities stink, are filthy dirty, centers of disease and filled with vermin of both the four legged, six legged and two legged sort. Cities can't produce their own food or fuel and they can't get rid of their own wastes. Studies show that they are black holes, blemishes on the environment, soaking up the resources and polluting thousands of square miles around them.

    The only question is where else do we put all those people?

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