Posted on 01/03/2003 12:05:30 PM PST by cogitator
Global Warming Found to Displace Species
[My short comments have been inserted and designated with bold font and brackets.]
Global warming is forcing species around the world, from California starfish to Alpine herbs, to move into new ranges or alter habits in ways that could disrupt ecosystems, two groups of researchers say.
The two new studies, by teams at the University of Texas, Wesleyan, Stanford and elsewhere, are reported in today's issue of the journal Nature. Experts not associated with the studies say they provide the clearest portrait yet of a biological world driven into accelerating flux by warming caused at least in part by human activity.
Plants and animals have always had to adjust to shifting climates. But climate is changing faster now than in recent millenniums, and many scientists attribute the pace to rising concentrations of heat-trapping greenhouse gases.
In some cases, species' ranges have shifted 60 miles or more in recent decades, mainly toward the poles, according to the new analyses. In others, the timing of egg laying, migrations and the like has shifted weeks earlier in the year, creating the potential to separate species, in both time and place, from their needed sources of food.
One academic not associated with the studies, Dr. Richard P. Alley, an expert on past climate shifts who teaches at Pennsylvania State University, said that climate had changed more abruptly a few times since the last ice age and that nature had shifted in response. But, he noted, "the preindustrial migrations were made without having to worry about cornfields, parking lots and Interstates."
Citing the new work and studies of past climate shifts, Dr. Alley saw particular significance in the expectation that animals and plants that rely on one another were likely to migrate at different rates. Referring to affected species, he said, "You'll have to change what you eat, or rely on fewer things to eat, or travel farther to eat, all of which have costs."
The result in coming decades could be substantial ecological disruption, local losses of wildlife and extinction of some species, the two studies said.
The authors express their findings with a certainty far greater than in the last decade, when many of the same researchers contributed to reports on biological effects of warming that were published by the Intergovernmental Panel on Climate Change, the top international research group on the issue.
The authors of one of the new Nature papers, Dr. Camille Parmesan, a biologist at the University of Texas, and Dr. Gary Yohe, an economist at Wesleyan University, calculated that many ecological changes measured in recent decades had a 95 percent chance of being a result of climate warming and not some other factor. [What is an economist doing commenting on climate and ecological issues?]
"You're seeing the impact of climate on natural systems now," Dr. Yohe said. "It's really important to take that seriously."
Some butterflies have shifted northward in Europe by 30 to 60 miles or more, with the changes closely matching those in average warm-season temperatures, Dr. Parmesan said. The researchers were able to rule out other factors habitat destruction, for example as causes of the changes.
Some of these changes meshed tightly with variations in temperature over time. Dr. Parmesan cited bird studies in Britain. There, populations of the great tit adjusted their egg laying earlier or later as climate warmed early in the 20th century, then cooled in midcentury and warmed even more sharply after the 1970's.
Over all, Dr. Parmesan's study found that species' ranges were tending to shift toward the poles at some four miles a decade and that spring events, like egg laying or trees' flowering, were shifting 2.3 days earlier a decade.
Around Monterey Bay in California, warmer waters have caused many invertebrates to shift northward, driving some species out of the bay and allowing others to move in from the south. [May be due to the recent strong El Nino in 1998.]
Authors of both new papers said they were concerned that such significant ecological changes had already been detected even though global temperatures had risen only about one degree in the last century.
They noted that projections of global warming by 2100 ranged from 2.5 to 10 degrees above current levels, should concentrations of carbon dioxide and other heat-trapping gases, which flow mainly from smokestacks and tailpipes, continue to rise.
By comparison, the world took some 18,000 years to climb out of the depths of the last ice age and warm some five to nine degrees to current conditions. [This is very misleading. The last glacial period experienced a gradual warming, then an abrupt cooling for 1000 years due to ocean circulation changes, then a very rapid warmup of 5-10 C in a couple of decades when normal ocean circulation was re-established. The sentence makes it sound like the warming over 18,000 years was entirely gradual. WRONG.]
"If we're already seeing such dramatic changes" among species, "it's really pretty frightening to think what we might see in the next 100 years," said Dr. Terry L. Root, an ecologist at Stanford University who was the lead author of one of the new studies.
The two teams of researchers used different statistical methods to analyze data on hundreds of species, focusing mainly on plants and animals that have been carefully studied for many decades, like trees, butterflies and birds. Both teams found, with very high certainty, a clear ecological effect of rising temperatures.
Several of the researchers said the effects of other, simultaneous human actions, like urban expansion and the introduction of invasive species, could greatly amplify the effects of climate change.
For example, the quino checkerspot butterfly, an endangered species with a small range in northern Mexico and Southern California, is being pushed out of Mexico by higher temperatures while also being pushed south by growing suburban sprawl around Los Angeles and San Diego, Dr. Parmesan said.
"The butterfly is caught between these two major human factors urbanization in the north and warming in the south," said Dr. Parmesan, who has spent years studying shifting ranges of various checkerspot species.
Dr. Alley said the studies illustrated the importance of conducting much more research to anticipate impending harms and devise ways to maintain biological diversity, for instance with green "wildlife corridors" linking adjacent pockets of habitat.
I have a pretty strong economics and statistics education, and I can't fathom how he would have calculated that.
I guess he would have figured the rate and extent of ecological change in some prior "normal" period. Assumed that rates of ecological changes over time are normally distributed, and then measured the more recent rates of ecological change. One could then, using the assumption of normal distribution, say that 'well, the more recent rate is high enought that there is only a 5% chance that it is random, and not the cause of some new factor.'
To do so, you would need to define what a rate of ecological change is, and what the data points are, for some prior period, and then for some current period. Impossible. You would then have to assume that the prior data is "normal". Which is dubious. You would then have to assume that rates of change over time are normally distributed. Also dubious. You would then have to assume that the 5% (the standard) chance did not occur, and that in fact it is the result of an outside factor (probable, but he could be wrong). You then have to assume that the only factor that has changed is climate warming, and not something else.
In short, he is full of crap.
The Left thinks it has found the perfect gambit. Let's make the weather the instrument of statist ideology, they say to themselves. But the plan will boomerang. The vagaries of weather patterns (sensitive dependence on initial conditions) will prove, and indeed already are proving, to be too chaotic for an indeological straightjacket, and human consciousness, steeped as it is in a long evolution of coping with weather, is not as easily deceived by chicken little descriptions of a falling sky as the statists would hope.
The NY times article or the papers?
There's a lot of documented evidence of ecological shifts over the 20th century due to warming. I don't see where it is dishonest to report that. If they attempt to use these observations to influence policy, then they are stepping out of their scientific bailiwick.
These studies build on earlier work that has shown seasonal shifts and changes in species distributions, along with ecological alteration, in response to the moderate warming of the 20th Century.
And what precisely does man have to do with this? Or better, what can or should man do about it seeing as temperatures seem to be returning to where they were 2000 years ago and therefore "ecological alteration" and "species distributions" are simply returning to their nominal state in response to conditions prevalent before "20th Century warming".
Figure 1-2 Climate of the last 2400 years
Figure 1-3 Climate of the last 12,000 years
No, this isn't impossible. It's been done in a number of paleoclimatic/paleobotanic studies. The rate of ecological change can be measured against the rate of climate (temperature) change using fairly direct measures of temperature, such as stable carbon or stable oxygen isotope ratios.
As you note, I think he goes out on a limb labeling the changes as both abnormal AND the result (at least partially) of human influence, but it is possible to compare current rates of ecological change to the rates of change that have occurred in the past.
First, mankind's activities may have something to do with the current rate of warming. We'll be more sure of that (or not) in a few years. Second, the warming rate over the 20th century, 0.6 C, is faster by about 2x than any century in the past 2000 years. The "squeezed" nature of your graph doesn't show this very well. Natural ecosystems can adapt to a temperature rate of change maximum of about 2 C/century, which may be (note the qualification) the rate of temperature rise that has taken place since the mid-1970s. So, if mankind's activities are responsible for the current rate of temperature change, then the possible of ecosystem collapse, rather than adaptation, exists. I think the best estimates of the rate of temperature change in the 21st century are about 2-3 C, and a very recent paper first-authored by Patrick Michaels appears to support my opinion. So the 21st century could be a period where many ecosystems will be significantly stressed by rapid climate change.
Here in the greater Washington, D.C. region, three months ago we were being indundated with drought stories. Now, after three months of heavy precipitation, we are actually experiencing flooding along the Potomac.
What we need in this country is more separation of science and big government. The problem is that you just can't sponge off the taxpayers by saying "this has all happened before, and everything is going to be O.K."
The computer models are exagerated enough how it is, to include the 10 degree number is a lie. One of the models was sabataged to provide the largest possible number, but yet that is the most widely quoted number even by people who should know better. Global Warmers make me sick. They are liars.
It's hard to know what the sample size would be, because it is hard to know what the total number of living organisms is. However, let's say we decide that we need a sample size of 1,000.
You would need to probably break that down in to a certain number of ecological climates, and then take a random sampling in each. Let's say we broke it down in to 10 climate zones, and we took a sample of 100 organisms from each.
How exactly would you select random samples?
Do you really think that this guy did that?
First, mankind's activities may have something to do with the current rate of warming.
Let's put a number to that "may" shall we?
http://www.clearlight.com/~mhieb/WVFossils/greenhouse_data.html |
Just how much of the "Greenhouse Effect" is caused by human activity? It is about 0.28%, if water vapor is taken into account-- about 5.53%, if not. This point is so crucial to the debate over global warming that how water vapor is or isn't factored into an analysis of Earth's greenhouse gases makes the difference between describing a significant human contribution to the greenhouse effect, or a negligible one. Water vapor constitutes Earth's most significant greenhouse gas, accounting for about 95% of Earth's greenhouse effect (4). Interestingly, many "facts and figures' regarding global warming completely ignore the powerful effects of water vapor in the greenhouse system, carelessly (perhaps, deliberately) overstating human impacts as much as 20-fold. Water vapor is 99.999% of natural origin. Other atmospheric greenhouse gases, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and miscellaneous other gases (CFC's, etc.), are also mostly of natural origin (except for the latter, which is mostly anthropogenic). Human activites contribute slightly to greenhouse gas concentrations through farming, manufacturing, power generation, and transportation. However, these emissions are so dwarfed in comparison to emissions from natural sources we can do nothing about, that even the most costly efforts to limit human emissions would have a very small-- perhaps undetectable-- effect on global climate. |
Role of Atmospheric Greenhouse Gases
(man-made and natural) as a % of Relative
Contribution to the "Greenhouse Effect"
Based on concentrations (ppb) adjusted for heat retention characteristics | Percent of Total | Percent of Total --adjusted for water vapor |
Water vapor | ----- | 95.000% |
Carbon Dioxide (CO2) | 72.369% | 3.618% |
Methane (CH4) | 7.100% | 0.360% |
Nitrous oxide (N2O) | 19.000% | 0.950% |
CFC's (and other misc. gases) | 1.432% | 0.072% |
Total | 100.000% | 100.000% |
Anthropogenic (man-made) Contribution to the "Greenhouse
Effect," expressed as % of Total (water vapor INCLUDED)
Based on concentrations (ppb) adjusted for heat retention characteristics | % of All Greenhouse Gases |
% Natural |
% Man-made |
Water vapor | 95.000% |
94.999% |
0.001% |
Carbon Dioxide (CO2) | 3.618% |
3.502% |
0.117% |
Methane (CH4) | 0.360% |
0.294% |
0.066% |
Nitrous Oxide (N2O) | 0.950% |
0.903% |
0.047% |
Misc. gases ( CFC's, etc.) | 0.072% |
0.025% |
0.047% |
Total | 100.00% |
99.72 |
0.28% |
|
STATUS
U.S.A. Endangered Species
Like you've pointed out, the Earth is not as fragile as some would have us believe. (I guess GW fits into the "man is evil" mantra held by many).
There are several ways that this has been done. One of the easiest ways to do it is to look at pollen grains in lake sediments. An assemblage of different pollen grains defines an ecosystem. The researchers then look at lakes at various latitudes and correlate changes in the characteristic pollen assemblages of a given system with temperature records. It's apparently fairly easy to discern ecosystem changes this way (there is an assumption that certain types of fauna are associated with characteristic flora, but that's easy to check with present-day ecosystem research).
It's hard to know what the sample size would be, because it is hard to know what the total number of living organisms is. However, let's say we decide that we need a sample size of 1,000.
That's unnecessary. A few preponderant species are used as key ecological indicators. I.e., the presence or absence of a particular type of pollen grain is a marker of a particular ecosystem. (Oceanographers do the same type of study with organisms called foraminifera.)
You would need to probably break that down in to a certain number of ecological climates, and then take a random sampling in each. Let's say we broke it down in to 10 climate zones, and we took a sample of 100 organisms from each.
You're partially correct here. It's necessary to examine assemblages from different climates.
How exactly would you select random samples?
They don't randomize, as far as I know.
Do you really think that this guy did that?
I don't know what he did, unfortunately. I'd have to read the paper and I probably wouldn't have a strong grasp of the statistical treatment as it is.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.