Silent_One said:
Notice how the studys you site allways have different projections.
First link - 3 degrees Fahrenheit (2 degrees Celsius)
Secound link - 1.4 and 5.8 degree C
Third link - 0.6 to 5.8 degree C
Which one do you believe?
It would appear that the 2nd & 3rd link are using simular data, which BTW, comes from the IPCC.
That's why I gave a range and explicitly stated "projected" instead of definitive.
Silent_One said:
I don't believe your manipulating what is being reported (although it was not clear at first where you got the data in the previous instances
) But lets look a the information shall we. Based upon the link you provided,
http://www.twnside.org.sg/title/twr125c.htm the folowing is stated in the article:
A unanimous report of hundreds of scientists from more than 100 countries has affirmed, on the basis of new and stronger evidence, that most of the warming over the last 50 years has been caused by human activities.
What "new and stronger evidence" are they refering to? According to the article the IPCC's first report, in 1990 "confirmed that climate change is a threat". Then in 1995 their second report project a temp. rise of 1 to 3.5 degree C by 2100. The last report, put out at the time of this article, says that "Warming is now expected to go up between 1.4 and 5.8 degree C between 1990 and 2100.' So what changed between reports? Well - here's an article that answers that question-
http://www.globalwarming.org/sciup/sci4-2-03.htm
What’s Behind the IPCC’s Latest Projections?
When the United Nations’ Intergovernmental Panel on Climate Change released its Third Assessment Report (TAR) in 2001, many were surprised that its projections for temperature increases had risen substantially. The IPCC’s 1996 Second Assessment Report (SAR) predicted that the earth’s temperature could increase by as much as 0.9 to 3.5 degrees Celsius. The TAR, however predicted a rise of 1.4 to 5.8 degrees C. In a paper published in the Journal of Climate (October 15, 2002), Thomas Wigley with the National Center for Atmospheric Research and Sarah Raper with the Climatic Research Unit at the University of East Anglia, ask the question, "Why are the more recent projections so much larger?"
The authors attempt to quantify how much of the change in projections was due to the new emissions scenarios presented in the IPCC’s Special Report on Emissions Scenarios, and how much was due to differences in the science used in the climate models. To determine this, the authors plugged the emissions scenarios responsible for the high and low ends of the temperature projections into the models used for the TAR, what Wigley and Raper call the "TAR science."
For the TAR’s high end, coal-intensive scenario, the "CO2 concentrations are remarkably similar" to those used for the high-end scenario in the SAR. The biggest differences between the two high-end scenarios are the assumptions about sulfate aerosol concentrations, which are thought to offset warming. "The large aerosol forcing differences arise because the SRES scenarios account for likely policy responses to sulfur pollution.... This leads to substantially lower SO2 emissions than for the [SAR scenarios]." There are also some differences in methane forcing and tropospheric ozone forcing. This exercise revealed a difference in forcing from changes in the TAR greenhouse gas cycle from 0.5 Watts per meter squared (W/m2) at the low end to 2 W/m2 at the high end.
The differences in science between the two reports refer to changes in the way the models handle complex climate processes. So it is not so much a change in science as a change in modeling. To determine how these changes affect the projections, Wigley and Raper compare the low and high-end scenarios using SAR science and TAR science. What they found was that "the effects on concentration projections for any give emission scenario are relatively small."
In fact, there was actually a reduction in CO2 forcing combined with increased warming. This was due primarily to two things—a change in a parameter that defines the relationship between CO2 concentrations and forcing and a change in how the thermohaline circulation (THC) was modeled. A slowdown in the THC, for example, would offset some of the projected warming due to higher greenhouse gas concentrations. In the TAR, the THC will not slow down as much as assumed in the SAR.
The result of these exercises reveals that very little of the change in temperature projections is due to changes in scientific understanding or better modeling, but due almost entirely to different emissions scenarios. "At the low warming limit, TAR science inflates the 1990-2100 warming for the [low-end SAR scenario] by around 34 percent," says Wigley and Raper. "At the high end, TAR science inflates the 1990-2100 warming for the [high-end SAR scenario] by around 4 percent." The rest of the high-end alarmist projection comes from changes in the worst-case storyline, which has little basis in reality. A full 79 percent of the change at the high-end projection came from the changed assumptions about sulfate aerosols alone, about which we know very little.
Personally I don't know weather modelling through and through. Though I wish I did considering it seems to be a quite interesting subject. However, I must point out that while I believe the 5.8 degree change in the new modeled numbers is far out when taking into account other sources, the old numbers do indeed jive with current scientific understanding of a more realistic 1 - 4 degree Celcius shift in temperature in the 21st century.
Notice that at the end of the quote, which you bolded, it states
A full 79 percent of the change at the high-end projection came from the changed assumptions about sulfate aerosols alone, about which we know very little.
Now correct me if I'm wrong, but that's basically saying that the difference from the original 1 - 4 degree shift to the newly calculated 1 - 5.8 degree shift was basically the change in assumptions regarding aerosol emissions. But in no way shape or form did that article repudiate the original numbers! Just the newly formed numbers. So even if you throw out the newly formed numbers, that still leaves, even conservatively (when taking into account the other sources available from the google search I provided), a 1 - 3 degree Celcius shift in temperature, which is what I stuck with in my table comparison on the last page.
Silent_One said:
Now, on to you slapping yourself
Natoma said:
Silent_One wrote:
Silent_One said:
Sorry, don't buy it. That paper was written to examine the potential impacts of climate change on the northeastern US. It was not written as a scientific paper regarding the rise in sea levels.
Again, sigh. What is one of the potential impacts of climate change? A rise in sea levels!
/me slaps head.
No, no, no. You got things backwards! The paper was written as a responce to the scenario of rising sea levels, not a paper to discuss the scientific evidence of climate changes and its impact. From the introduction of the article:
As greenhouse gases build-up in our atmosphere, one of the most likely impacts of climate change is rising sea levels. Sea level will rise because warm water expands and glaciers and ice sheets melt, adding water to the ocean. Sea-level rise, already occurring and projected to occur 2-4 times faster in the 21st century, could inundate low-lying areas of the Northeast, many of which include densely populated locations.....
The article then talks about loss of land mass, erosion, wetlands, societal and economic Impacts, and Strategies to Address Potential Impacts of Sea-Level Rise....Again, its's not an article analyzing scientific data, it's a paper based upon the assumption that the sea level is going to rise. To them , it's a given!
/me slaps your head!
I don't understand what you're getting at here. I'm reading what you wrote, as well as what the article wrote, and it seems to me quite clearly that the article is saying that one of the impacts of climate change is a rise in sea levels.
Silent_One said:
Sorry, don't buy it. That paper was written to examine the potential impacts of climate change on the northeastern US.
Then you write something which was really confusing, especially given the quote you provided:
Silent_One said:
No, no, no. You got things backwards! The paper was written as a responce to the scenario of rising sea levels, not a paper to discuss the scientific evidence of climate changes and its impact.
So, how did I get things backwards when first you state that
the paper was written to examine the potential impacts of climate change in the US, then you state that the paper was written
not as an examination of the evidence of climate changes and their impact, but as a response to the scenario of rising sea levels?
I'm sitting here doing a :? trying to decipher that one.
Original Article said:
As greenhouse gases build-up in our atmosphere, one of the most likely impacts of climate change is rising sea levels. Sea level will rise because warm water expands and glaciers and ice sheets melt, adding water to the ocean. Sea-level rise, already occurring and projected to occur 2-4 times faster in the 21st century, could inundate low-lying areas of the Northeast, many of which include densely populated locations....
They state that one of the most likely impacts of climate change is rising sea levels. And then they explain
why sea levels would rise due to warming temperatures due to a build-up of greenhouse gases in our atmosphere.
Silent_One said:
To me, the point of this discussion with you Natoma, is to show that their is much to be take with a grain of salt. If you believe outright that the worst is coming, and try to show "proof", I'm sure I can find "proof" that your proof is wrong. Such is the nature of the current debate. Personally I believe some of the information, some of the time, and not the worst case - best case scenarios.
I read the urls that you provided, as well as the quotes you provided, and as I said before, I'll say again. Until we have definitive long term proof that the IPCC numbers were incorrect, then they're the best ones we have.
However, the second quote block that you provide has many clues as to why Satellite data *and* ground based data are important to the discussion in tandem, and not opposition:
Scientists have been puzzling over the difference in temperature trends between the surface layer of the atmosphere up to about 5,000 feet and the layer above that known as the troposphere. Since 1979, when scientists began using satellites to take the temperature of the troposphere, it appears that even while the surface has apparently warmed, tropospheric temperatures have remained steady. This is puzzling because greenhouse theory says that the troposphere should warm first, followed by the surface layer.
So now we have a discrepancy in the theory of greenhouse gas warming. However, that discrepancy in the theory does not negate the fact that the surface temperatures have increased far more than the trophospheric temperatures have increased. The article goes on to give a potential explanation for this difference:
This scientific controversy even merited special attention from the National Research Council, which assembled a panel to assess the situation. It concluded that both the surface data and the satellite data are correct, but only speculated about the possible causes.
According to the study, "The surface data suggests a warming of about 0.25 degrees C, while the satellite data shows no significant increase." Because the satellite data began in 1979, however, it has been noted that it is too short to "infer trends from any of the series since the trends estimated depend greatly on the subintervals chosen." Fortunately, the close agreement between the satellite and weather balloon data, which also measures tropospheric temperatures, allows for a longer time period to be considered.
Looking at the balloon data the study notes that there was a pronounced jump in the atmospheric temperature of about 0.25 degrees C in 1976. The surface followed suit but at a slower pace, taking about ten years to catch up. The delay in the surface data is probably due to the heat capacity of the oceans, which is related to overall climate sensitivity. The delayed response also accounts for the discrepancy between the surface-based temperature data and that taken from satellites. Since the satellite data began in 1979 it missed the jump in 1976, which was documented in the slower surface warming.
Keep in mind that I noted the fact earlier in this discussion that the Oceans act as not only a natural carbon loading mechanism, but a giant heatsink.
I don't think the numbers are in any way incongruous, unless you choose to believe that both are immutable unto themselves and cannot corrolate with any other data source.
From the article you provided, it seems that scientists are using *both* forms of data capture in order to glean the true picture of what's going on. Land based data *and* satellite based data, with a smattering of balloon data as well.
As you stated earlier, I don't particularly believe that in 100 years we're all going to be underwater. However, I do believe that we are changing the planet for the worse by our actions. The worse, only because we are not in equilibrium with the planet. We remove far more resources, and pollute the earth far more, than the earth can replenish and remove naturally. We need to curtail our activities to bring them back in line to what the earth can support.
The numbers provided by the scientific community merely illustrate how we are changing our environment and how, if we don't curtail our activities, things can get very bad for us.
Think about it this way. Go back 100 years when heavy metal pollution of our streams and rivers was common place. You think that if the US government didn't institute guidelines on environmental safety that our streams and rivers would be teeming with life today? That if environmental solutions to vehicle pollution weren't legislated that we'd still have wonderful air quality today?
The reason why our planet isn't in worse shape is because people in the past realized that hey, we need to change our ways. And this was *before* all of the satellites and computers and whatnot that help shape our world today. Now we're able to analyze the data from thousands of years ago to the present day, and project based on our current usage patterns, where the earth most likely will be in another century or two. It is not a death knell of inevitability. Merely a warning that this *may* occur.
To ignore this as some in this discussion, nay many around the world, have is foolhardy at best, and suicidal for future caretakers of this world at worst. If the people of the past said "I don't care what happens tomorrow. I won't be around," we'd have even worse toxic waste pollution, air quality, etc etc etc than we have today. It's our duty to make sure we try and keep the planet as livable as possible for the human race, because quite frankly we're the only species in the history of this planet that has the intelligence to do so on a global scale.
It's our responsibility. If you believe in god, then you know that god made man to be the caretakers of the earth. Not its destroyers. Even if you don't believe in god (myself in that group), science tells you that we've got no place else to go. So if we muck up this planet, we're screwed royally.
But that's maybe a discussion for another thread.
