Posted on 12/03/2003 11:38:50 AM PST by cogitator
Edited on 07/12/2004 3:40:53 PM PDT by Jim Robinson. [history]
CAMP SPRINGS, Md., Dec. 1 (UPI) -- Two U.S. government scientists said Monday their research proves human activities are affecting global climate.
Thomas Karl, of the National Climatic Data Center in Camp Springs, Md., and Kevin Trenberth, head of the National Center for Atmospheric Research's climate analysis section in Boulder, Colo., said their research proves industrial emissions have been the dominant influence on climate change for the past 50 years. The most important of these emissions is carbon dioxide, a greenhouse gas that traps solar radiation and warms the planet.
(Excerpt) Read more at washingtontimes.com ...
Top Scientists Conclude Human Activity is Affecting Global Climate
Arlington, Va.—Two of the nation's best-known atmospheric scientists, after reviewing extensive research by their colleagues, say there is no doubt human activities are having measurable—and increasing— impacts on global climate. Results of the study, which appears in the December 5th issue of the journal Science as part of a "State of the Planet" assessment, cites atmospheric observations and multiple computer models to paint a detailed picture of the climate changes likely to buffet Earth in coming decades, including rising temperatures and an increase in extreme weather events such as flooding.
Thomas Karl of NOAA's National Climatic Data Center in Asheville, N.C., and Kevin Trenberth, director of the Climate Analysis Section at the National Center for Atmospheric Research (NCAR) in Boulder, Colo., conclude that industrial emissions have been the dominant influence behind climate change for the past 50 years, overwhelming natural forces. The most important of these emissions is carbon dioxide, a greenhouse gas that traps solar radiation and warms the planet. Trenberth's research is funded by the National Science Foundation (NSF), the independent federal agency that supports fundamental research and education across all fields of science and engineering.
"There is no doubt the composition of the atmosphere is changing because of human activities, and today greenhouse gases are the largest human influence on global climate," they write. "The likely result is more frequent heat waves, droughts, extreme precipitation events, and related impacts, e.g., wildfires, heat stress, vegetation changes, and sea-level rise which will be regionally dependent."
"Many important climate research accomplishments over the past several decades have led to major improvements in understanding and predicting our climate," said Jay Fein, director of NSF's climate dynamics program. "Karl and Trenberth summarize those accomplishments in terms of what we have learned about our climate and the many factors that force it. As they point out, however, there still remain important uncertainties, both in terms of climate forcing and climate response. Addressing the uncertainties will require continuing research and model development, underpinned by high-quality, long-term global environmental observations and social and economic data."
Karl and Trenberth estimate that, between 1990 and 2100, global temperatures will rise by 1.7°C to 4.9°C (3.1°F-8.9°F). The increase would have widespread impacts on society and the environment, including melting the great ice sheets of Greenland and Antarctica and inundating the world's coasts. The authors base their estimate on computer model experiments by a number of climate scientists, observations of atmospheric changes and recorded climate changes over the past century.
Carbon dioxide levels in the atmosphere have risen by 31 percent since pre-industrial times-from 280 parts per million by volume (ppmv) to over 370 ppmv today. Other human activities, such as emissions of sulfate and soot particles and the development of urban areas, have significant but more localized climate impacts. Such activities sometimes cause temperatures to rise or fall, but not by enough to offset the impact of greenhouse gases.
If societies successfully cut emissions and stabilized carbon dioxide levels in the atmosphere, temperatures would still increase by an estimated 0.5°C over a period of decades, Karl and Trenberth warn. This is because greenhouse gases are slow to cycle out of the atmosphere. "Given what has happened to date and is projected in the future, significant further climate change is guaranteed," the authors state.
If current emissions continue, the world would face the fastest rate of climate change in at least the past 10,000 years. This could potentially alter ocean current circulations and radically change existing climate patterns. Moreover, certain natural processes would likely accelerate the warming. As snow cover melts away, for example, the darker land and water surface would absorb more solar radiation, further increasing temperatures.
Karl and Trenberth say more research is needed to pin down both the global and regional impacts of climate change. Scientists have yet to determine the temperature impacts of increased cloud cover or how changes in the atmosphere will influence El Niño, the periodic warming of Pacific Ocean waters that affects weather patterns throughout much of the world. The authors call for multiple computer model studies to address the complex aspects of weather and climate. The models must be able to integrate all components of Earth's climate system-physical, chemical and biological. This, in turn, will require considerable international cooperation and establishment of a global climate monitoring system to collect data.
"Climate change is truly a global issue, one that may prove to be humanity's greatest challenge," the authors conclude.
[And may I say that I certainly disagree with that conclusion; humanity's greatest challenge will be to maintain the economic growth that improves the lives of people in countries around the world.]
ROTFL....I just love how these wack jobs use their own global warming computer models to prove global warming. Our computer models which we programed to say so, proves it so. These guys are agenda-driven liars, not scientist.
Maybe we should wait to read the article before we conclude that they are only looking at the results of their in-house models. Trenberth does atmospheric modeling; I don't think that Karl does - he's more of a data wonk.
Bunch of morons...
...have any of these computer models accurately modeled climate variation for any 100 year-ish period over the last 100,000 years or so?
Have any of these models accurately modeled the beginning or end of a past ice age?
Have any of these models accurately modeled events like the "Little Ice Age" or the "Midieval Warm Period?"
Just wondering...
And the number one source of that CO2? Human beings. So who is the number one violator of the atmosphere? China - they have more people than anyone else. So why were they exmpted from any of the provisions of the Kyoto debacle? You supply the answer.
Yes. Particularly true for the 20th century (including the last couple of years).
Have any of these models accurately modeled the beginning or end of a past ice age?
If you mean the initiation or termination of glacial periods in the Pleistocene, no. The reason is that these events "begin" and "end" at abrupt points, which for models are discontinuous boundary events. I.e., by necessity due to the rapid change in conditions that occurs at these points, models that rely on equations to describe state conditions cannot determine a stable point to "start". (The analogy is that of a pile of sand, like in an hourglass. If you watch the pile of sand, it is slowly rising, i.e., increasing in volume. That is relatively easy to model. But if you also watch, there will be moments at which a portion of the pile suddenly slips down the slope. Even though the critical angle of slip can be determined from particle characteristics, pinpointing the moment when the slip will occur is impossible.)
Have any of these models accurately modeled events like the "Little Ice Age" or the "Medieval Warm Period?"
Given that the global extent and intensity of these events are still important research subjects, I would say no. One of the problems is that the most intense cold of the LIA may have been due to some large volcanic eruptions, notably the 1600 eruption of Huayputina in Nicaragua and the famous 1815 eruption of Tambora in Indonesia. Unless the models are "allowed" to incorporate the effects of volcanic forcings like this, they will not duplicate the observed climate patterns.
As is commonly the case with regards to climate, answers aren't simple even if the questions appear to be.
No, it took scientists to add validation to their claims of global warming and the human effect.
It's called dry-labbing it. You start with an assumption and find data to confirm it - even if you don't really find any.
Kinda like objective reporting.
Not exactly. Where'd you get that idea?
Translation : Send more money!
That's all I needed to know. They are liberal, nut-cases, with cushie govt. jobs and retirement plans. They don't have to do real work for a living and have nobody to answer to for their performance. More than likely they work from 10:00am until 3:00pm (if that) each day and get over one month of vacation per year. Of course they don't have a grasp on reality.
All of the computer models are pretty much bunk. They all assume global warming. Computer models just say whatever the modeller wants them to say. There are so many assumptions and so many unknowns, models just get tweak until the desired results are reach. Using computer models with so many worst case assumptions and so many unknowns as a basis for scientific proof is 100% pure bullshit.
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