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Space Science

Satellites Show That Earth Has a Fever 596

Roland Piquepaille writes "A recent study from NASA says that satellites are acting as thermometers in space. Contrary to meteorological ground stations which measure the air temperature around two meters above the ground, satellites can accurately measure the temperature of the Earth's skin. And this new study, which covers the 18-year period going from 1981 to 1998, shows that the Earth's temperature is rising 0.43C per decade instead of the O.34C found by previous methods. Unfortunately for us, if satellites can more precisely measure this rise of the Earth's temperature, they cannot cure this fever. This overview contains more details and a spectacular image showing the European heat wave of the summer of 2003."
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Satellites Show That Earth Has a Fever

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  • Re:So? (Score:4, Informative)

    by AtariDatacenter ( 31657 ) on Friday April 23, 2004 @03:24PM (#8953102)
    Worst case scenerio?

    Global warming not only increases, but accelerates in a self-feeding reaction that extinguishes all life* on the planet Earth.

    Don't you love worst case scenerios?

    * - Well, any life worth talking about, anyhow. Do we really have to count those microscopic volcanic organisms?
  • Re:So? (Score:2, Informative)

    by mrdogi ( 82975 ) <> on Friday April 23, 2004 @03:32PM (#8953180) Homepage
    To add a bit to this, I have been told (sorry, don't have any info on details, I'll see if I can find some) that during this period of Earth's rise in global tempratures, Mars is also warming by a similar amount (given that it is farther from the sun, and all that). So, this global warming seems to have very little, if anything, to do with "green house" gases.
  • Well, actually, (Score:5, Informative)

    by Space cowboy ( 13680 ) * on Friday April 23, 2004 @03:44PM (#8953313) Journal
    Quite apart from the fact that sometimes life didn't go on (which ought to be enough to concern anyone), if you look at how these phenomena manifest, you'll see that it's typically not a linear process. There's normally a critical point over which X happens and below which Y happens. If X is lethal to human life (snowball earth, greenhouse earth) then we'd damn well better hope we stick with Y.

    A case in point is the atlantic conveyer (the 'Gulf Stream' to us Brits). If the conveyer stops, an absolutely massive amount of energy will cease to be delivered to where it currently is. The knock-on effects aren't really model-able, we just don't have the knowledge, but since staggeringly enormous amounts of warmth would cease to be delivered to the UK coastline, you could assume it will get colder, even if you don't know quite how much. To give some perspective, it generates a difference of approximately 20 degrees celcius between points at the same latitude. 20 degrees of delta-T over several hundred billion tons of water is a lot of energy to be dependent on far-easier-to-change salinity level.

    The atlantic conveyer depends on salinity in different parts of the world. If it rains more (in places that it currently rains little) and rains less (in places where it currently rains significantly) the saline levels will change, and the conveyer will be affected - at the critical point, it will simply stop. There's no obvious way we could restart it either. Shifting several hundred billion tons of water is way beyond our capabilities, and restoring the initial conditions may not be sufficient.

    I guess I'm sufficiently worried about the consequences (which we will not be able to counter) to pay some heed to people who try to assess risk under next-to-impossible scientific conditions. I guess, given the potential consequences, that I'm willing to listen more to those who get off their backsides and put some effort into the analysis than people who sit around saying, 'hell we've had ice ages before and we will again'.

    Actually humankind hasn't had ice-ages before, and to suggest we'd just cope is hubris of the highest order. We live in a highly technological society, and yes, given an immense struggle I think we would probably cope, as in 'Western civilisation' would cope. Countless millions would die in poorer, less developed, and simply unluckily-positioned countries as weather systems went out of control. One other thought is that a highly-structured, lean-and-mean (due to commercial pressures, mainly) society is a vulnerable society. If central America were reduced to a desert (unlikely, but possible) then the food chain would break within the US, and other countries would have a hard-enough time to feed their own. 280 million people is a lot of mouths...

  • Re:So? (Score:3, Informative)

    by 2marcus ( 704338 ) on Friday April 23, 2004 @03:49PM (#8953356)
    Um. Anti-ozone pollution is _not_ the cause of global warming. Actually, ironically enough, it is the opposite - the ozone hole over the antarctic is one of the reasons that the antarctic has _not_ warmed much over the last 30 years.

    Anyway, yes, there is natural variability. But humans have dumped enough GHGs into the atmosphere that our contribution is an order of magnitude larger than the sun's variation over the last 250 years. page 8, for a reference.

    Finally, some people have proposed putting sunshades in orbit or the equivalent, but it seems like it first we can try to reduce our contribution by controlling some of our emissions.
  • by Anonymous Coward on Friday April 23, 2004 @03:53PM (#8953400)
    You know the thing is that Al Gore always backs his warnings up with cold hard data.

    This is something the Republicans need to start doing. They have far more opportunity for education and far more chances to understand the big picture, but it was the Republicans that threw out the antecdotal data that Al Gore didn't know what the fuck he was talking about simply because he gave the speech on the coldest day in the near recorded history.

    One of the things people fail to understand is that Global Warming doesn't mean *EVERYTHING* is getting warmer, but that there are enough of a *GLOBAL* change that it effects local temps.

    What does that mean for all of us? It means wilder temperature fluxuations for the most part. In most of the US, we can actually expect colder winters because of global warming, but also unpredictable weather change. I can remember riding my motorcycle on an 80 degree day a few years ago in the middle of December in the middle of Indianapolis up to Chicago (the trip back, however, wasn't as pleasant). I can also remember a few years back when we were getting snow storms almost up to May.

    This is what Global Warming is going to do. you may never feel the weather being warmer, but it will be warmer and less predictable.

    Oh year, and its also said that according to US military data that was prepared specifically in regards to how the military needs to plan and strategize for future situations that Global Warming if all goes the way their scientists say it will, most of the US's west coast will loose what little natural rain fall it gets in the next 30 to 50 years. The artic starts a meltdown just barely and it ruins the weather patterns over that side. By the same token, Russia is said to actually get MUCH colder -- which the military supposes means that the Russians will then be far more interested in the Middle East than they are today, maybe leading us into another 'cold war' -- and maybe making Russia one of the powerhouses of Europe once again as they continue to hold some of the largest untapped oil reserves out there.

    Antecdotes mean very little. Idiots with their soundbytable (???) sentences deserve to be treated as the idiots they are. I have far more respect for folks like Al Gore than anyone here on this site...
  • Re:So? (Score:2, Informative)

    by hikerhat ( 678157 ) on Friday April 23, 2004 @04:02PM (#8953519)
    Your premise is: because the Earth's temperature fluctuates over time humans cannot have an impact on Earth's temperature.

    Your premise is false, so your argument is invalid.

    Then you go and cite a bunch of sources that say that the Earth's temperature fluctuates over time. Duh. We already know that, and it doesn't support your premise at all. You need to cite evidence that human activity doesn't cause the Earth's temperature to change.

    It is true the Earth's temperature fluctuates over time. It is also theorized, and back by strong evidence, that human activity can affect the global climate.

    Finally, you confuse theory with fact. Let's not "just drop it" (funny the way you say it, as though you are member of the community of people who are actually studying this issue). It is a theory, with supporting evidence. You can go ahead and drop it, but I suggest people who actually understand the issue and study it continue to work on it. That's what people do with supported theories. They work on proving or disproving them.

    You should probably take a few basic logic and science classes before posting any more comments to threads dealing with scientific theories. And, given your +4 rating, the moderators should take some of those classes as well.

  • by SuperBanana ( 662181 ) on Friday April 23, 2004 @04:08PM (#8953620)
    Paint everthing white

    I know you're joking, but parking lots and roads are responsible for altering weather patterns and causing local climate changes. Birds have even adapted to following highways because of the thermals they generate...

  • by Van Halen ( 31671 ) on Friday April 23, 2004 @04:09PM (#8953622) Homepage Journal
    I happen to work for a company that manufactures and sells some of these satellite-based temperature sensors to the government. I actually work on the ground processing software for one of them, which has all kinds of neat algorithms for turning raw microwave spectrum measurements into meaningful science data, including surface temperature and air temperature at several different levels of the atmosphere. If anyone is interested in the technology behind them, here are just a few of the sensors used by the US government for these purposes:

    MSU - 1970s era air temperature

    AMSU - next generation of MSU, several are flying on US and European satellites ATMS - next generation AMSU, scheduled for first flight in a few years SSM/T-1 - old 1970s/80s era air temperature sensor, the last one launched in 1999 SSMIS - next generation SSM/T-1 that also combines functions of 2 other older sensors (atmospheric water vapor and a ton of surface data like ice concentration, sea surface wind speed, soil moisture, etc), the first of 5 launched in October of last year CMIS - next generation SSMIS scheduled to fly by the end of the decade

    All of the above are what are known as microwave sounders or radiometers. They look at radiation in specific bands in the microwave region of the spectrum (based on oxygen absorption lines) to infer air temperatures.

    It looks like the study in the article was using MODIS [] and TOVS [] data. TOVS consists of some of the above instruments - MSU and AMSU in particular for this application. MODIS is another sensor that doesn't look at the microwave region of the spectrum, so it's out of my area of expertise. Look at the website for more info on that if you're interested. :)

  • Re:Well, actually, (Score:4, Informative)

    by Space cowboy ( 13680 ) * on Friday April 23, 2004 @04:10PM (#8953642) Journal
    Just peachy doesn't really do it justice:

    From a google search []

    [However, According to a Discover article:

    "... people all over the world are amazingly similar. Some anthropologists believe that this genetic homogeneity is the result of a "population bottleneck"--that at some time in the past our ancestors went through an event that greatly reduced our numbers and thus our genetic variation. Based on estimates of mutation rates, Penn State geneticist Henry Harpending says the bottleneck happened sometime after ... 100,000 years ago and before a population increase ... around 50,000 years ago. Now archeologist Stan Ambrose of the University of Illinois has linked Harpending's theory with geologic evidence to explain what caused the bottleneck--a giant volcanic eruption. ... Mount Toba in Sumatra blew 800 cubic kilometers of ash into the air--4,000 times as much as Mount St. Helens--the largest volcanic eruption in more than 400 million years. Toba buried most of India under ash and must have darkened skies over a third of the hemisphere for weeks. ... a six-year global volcanic winter ensued, caused by light-reflecting sulfur particles lingering in the atmosphere. Average summer temperatures dropped by 21 degrees at high latitudes, and 75 percent of the Northern Hemisphere's plants may have died. ... A thousand-year ice age began ... caused perhaps by an increasing amount of snow that failed to melt over the summer. This snow cover would have reflected more sunlight off Earth's surface, making the world still colder. The effect on humans, who had been enjoying a relatively warm period, must have been devastating. ... Perhaps only a few thousand people ... survived. ...".]

    If that's 'peachy', I'd sure-as-hell not want to come across anything 'hard'. Granted it's just one view, but then any one person (you and I included) only have one view as well...
  • by 2marcus ( 704338 ) on Friday April 23, 2004 @04:19PM (#8953773)
    Your link talks about 0.05% increases in solar radiation per decade. Radiative forcing increases due to GHGs are nearly 1% over the last two centuries. Even if the sun has been steadily increasing at the 0.05% rate for 2 centuries, the two trends would be of comparable magnitude - and the human one is accelerating.

    The Sun may be big, but without the magnifying glass it isn't likely to fry the ant...
  • More satallite data (Score:3, Informative)

    by bm_luethke ( 253362 ) <luethkeb@com c a s t . n et> on Friday April 23, 2004 @04:36PM (#8954000)
    Here [] shows some stallite atmospheric data that shows a cooling trend.

    So, which one to believe is the "true" measure of our global climate?
  • Re:So? (Score:4, Informative)

    by schon ( 31600 ) on Friday April 23, 2004 @04:41PM (#8954047)
    At a rise of .024 deg C a year, I seriously doubt the flooding and and mass migration will happen in a short enough span to cause "chaos"

    Really? Do you know the difference in global temperature between the last ice age, and now?

    Approximately 3 degrees celsius.

    How long ago was that?

    10,000 years.

    If the temperature is now changing .042 degrees per year (re-read the article - .42 per decade is .042 per year), that means that it's progessing a couple of orders of magnitude faster than it did in the past.
  • by Phantom_of_the_Opera ( 111341 ) on Friday April 23, 2004 @04:41PM (#8954052)
    0.024 deg C a year represents a huge amount of energy.
    In the oceans alone, that is about 24 thousand peta-joules of

    What does that mean? It's just a number. I don't know the significance of it, but I couldn't dismiss it offhand.
  • by Anonymous Coward on Friday April 23, 2004 @05:12PM (#8954396)

    The satellite data shows a 0.43 increase while the air temp measures show 0.34. That means the orginal poster was wrong in stating that there was more enegy in the air.
  • Re:So? (Score:0, Informative)

    by gfxguy ( 98788 ) on Friday April 23, 2004 @05:33PM (#8954613)
    Did you not read the previous responses? The world has gone from hot to cold to hot to cold over and over again for over 4 billion years.

    It's been shown with data available that the temperature has been going up (on average) since people have been able to measure it accurately. The world is in a natural warming state. We could stop using fossil fuels at all and it's not going to keep the planet from warming.

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