I showed it. Many, many, many times.
No you have not. You have stated a belief in a consensus. You have not shown it to be so across the whole scientific community. And try as you may, you are not going to show that.
Everyone knows this, and this is a concept you still are having difficulty with. Humans contribute to climate change. Meaning that natural phenomena are acknowledged but human activity appears to have an additional effect. It could be as little as a 1 or 2% contribution but there appears to be a contribution. This has been addressed before so please try not to bring it up again.
I'll bring up whatever I want. No one has ever been able to show what the supposed human effect on global climate is. There is a correlation between emissions of carbon dioxide and a slight increase in temperature, and computer model forecasts that project what the effects might be. There is, as of the present, no way to discern an alleged human signal from natural climate activity. That seems to be exceedingly difficult for you to understand.
Oh, and
you brought up degree this time. Not me.
I'm a bit baffled by these paragraphs...
Only because you don't quite grasp the breadth and range of climate research. The very subject deals with
constant change. You have made an assumption on the basis of your reading of a few review articles that assert a human effect on climate that you grasp the state of the science. In fact, the state of the science is ongoing. There has been an assertion that humans contribute to climate change; true. This hypothesis has been stated and measurements as to whether that hypothesis holds water or not are under way. That's pretty much where things are at.
Science is about having an open mind, examining the evidence as a whole and questioning what we're told. And I hope people will question the politicians and lay journalists and look for real unbiased scientific evidence before making up their minds. The propaganda machine can be powerful. The tobacco industry has spent billions of dollars trying to convince us that smoking is safe. The first studies linking smoking to lung cancer came out in the 1950s... that's right, the 1950s. But scientists were no match for the tobacco giants.
As I indicated earlier, the overwhelming "propaganda" as you call it is one that automatically assumes that a human effect on climate is not only a fact, but presently the primary driver of climate. There are plenty of scientists who study climate who are keeping an open mind and not asserting any published position with respect to human activity drives climate or not. The trouble is that if any scientists questions the belief of this supposed consensus, the lay press, environmentalists and politically active scientists are label those individuals as "deniers" or dupes of the oil industry. You have made some casual allusions to this yourself.
As to being open minded, I was speaking to you,
not to science.
Scientists can be quite capable of bias. You yourself seem to be well aware of the lay press and the conspiracy theories since you cite them so often.
There is hardly an alternate argument in science though. It is generally accepted that humans contribute to climate. I would teach students to examine the evidence, which is what I'm trying to do here.
There are a number of alternate hypothesis as to why there has been a slight change in temperature over the last 100 years. Many of them revolve around human emissions of C02. I have provided two papers earlier that show there is a significant potential bias with respect to where surface temperature measurements stations have been located over time. This has problem has been recognized for over 100 years.
You're not getting it. Humans contribute to climate change. They are not the sole cause.
You are not getting it. There is an assertion that humans contribute to climate. There are suggestions how this is being done. These things are under ongoing examination.
Please don't bring up natural causes again, it's been addressed several times. Climate researchers believe humans contribute in addition to natural factors. Issue addressed, end of issue, will not be brought up again.
I'll bring up natural causation as opposed to human causation when I see it necessary to do so. Climate is a natural phenomena that can be defined by change. Why do you presume to define what can or cannot be mentioned here?
Exactly. This is why it's important that the public knows that there is a scientific consensus so that they won't be swayed by smooth-talking politicians.
Your bias is showing through. Your open-mindedness is not.
Strange. I don't remember bringing up my credentials, which are not at all relevant to this issue.
Oh, don't be so coy. They have been mentioned on this board more than once. Your remark suggested that you teach. Do you?
Nice try, but you're changing the subject again. You're suggesting now that there is a consensus but it's because there's a conflict of interest at the IPCC. It's a fair point but you're flip-flopping. So what is it? Is there a consensus or not?
There's a consensus at the IPCC. But the IPCC is not whole scientific community, either.
Yup, and if the Bush government can acknowledge (finally!) that humans affect climate, perhaps you should consider it too.
That's politics.
Are you suggesting I do something on the basis of what Bush does? That's actually funny.
So you're pretty much flying solo here.
That's what you think.
You requested some proof, here are a few articles. Trust me, I didn't try too hard. Nevertheless, I'm sure you will find some fault, so why should I waste my time if you with your supposedly open mind won't bother to look and inform yourself.
First off, the theory of AGW induced climate change states that the warming signal will start, and be the strongest, at the poles. This has not been seen.
Graversen, R.G., et al., 2008. Vertical structure of recent Arctic warming. Nature, 541, 53-57.
The authors shows that there is a poor correspondence between the observed patterns of temperature change in the arctic and those predicted to occur by climate models over the high latitudes of the Northern Hemisphere.
Polyakov, I. V., et al. 2003. Variability and Trends of Air Temperature and Pressure in the Maritime Arctic, 1857-2000. Journal of Climate 16: 2067-77.
Analyzing data from land stations and ocean buoys, the authors found a strong warming trend between 1917 and 1937, and a slight cooling since 1937.
Przybylak, R. 2002. Changes in seasonal and annual high-frequency air temperature variability in the Arctic from 1951 to 1990. International Journal of Climatology 22: 1017-33.
The author shows that according to instrument observation, Arctic temperatures of the 1950’s were higher than those of the late1980’s. The highest recorded temperatures since the start of instrumental observations occurred during the 1930’s. The author notes that no tangible manifestation of the greenhouse effect could be identified.
Mackintosh, A., White, D., Fink, D., Gore, D., Pickard, J., and Fanning, P. 2007. Exposure ages from mountain dipsticks in Mac.Robertson Land, East Antarctica, indicate little change in ice sheet thickness since the Last Glacial Maximum. Geology 35 (6), 551-554
The East Antarctic Ice Sheet is stable and has been so since the end of the Last Glacial Maximum.
Doran P.T. et al. 2002. Antarctic climate cooling and terrestrial ecosystem response. Nature Advance 415: 517-20.
Spatial Analysis of Antarctica meteorological data demonstrate a net cooling on the Antarctic continent between 1966 and 2000.
The theory of anthropogenic climate change asserts that the ocean levels will rise due to a warming atmosphere and increase in polar ice loss. In 1990 the IPCC predicted that ocean warming caused by human activity would produce sea level rise between 30 and 100 centimetres by 2100. In 2001, the IPCC predicted an ocean rise between 9 and 88 centimetres over 100 years. In 2007, the IPCC’s most recent assessment went on to predict a sea level rise between 18 and 59 centimetres. In actual fact, sea level has been rising
naturally for over 10,000 years for a variety of reasons since the end of the last glacial maximum. Measuring average global sea-level rise seems simple, but such a measurement is made very difficult largely due to vertical movements of the earth’s crust. During a glacial period, an enormous volume of ice pushes down on the crust. When the ice melts, the crust rebounds. This rebound is still in effect. Scientists have attempted to account for this effect using numerical “Glacial-Isostatic Adjustment” routines in when estimating of accurate sea-level rise. Changes in tectonic activity, ocean currents, wind and gravitational patterns complicate the measurement of true sea level considerably.
Wöppelmann, G., Martin, B., Miguez, M., Bouin, M. N., and Altamimi, Z. 2007. Geocentric sea-level trend estimates from GPS analyses at relevant tide gauges world-wide. Global and Planetary Change, 57, 396–406.
When the authors factored land motion into their the estimates of sea-level rise, they determined a global value of 1.31 plus or minus 0.30 mm per year compared to the 1.8 plus or minus 0.5 mm per year value provided by the IPCC for the recent half century, This is below the lowest end of the IPCC range of predictions.
Kolker, A.S. and Hameed, S. 2007. Meteorologically driven trends in sea level rise. Geophysical Research Letters 34: 10.
The authors show that determining the rate of global sea level rise is complicated by many natural local variables that must be taken into consideration when attempting to determine any accurate trend in sea level rise. They conclude that based on more accurate assessment of local variability, a sea level rise of less than one third of that stated by IPCC conclusions. The authors take no position with respect to anthropogenic causation.
Harrison, D.E., and M. Carson. 2007. Is the World Ocean Warming? Upper-Ocean Temperature Trends: 1950–2000. Journal of Physical Oceanography, 37, 174-187.
The authors make no statement about any global trend over the past 50 years – none is identifiable. There is not enough data to detect such a change in heat content. There is no clear or obvious trend.
Leuliette, E.W., Nerem, R.S. and Mitchum, G.T. 2004. Calibration of TOPEX/Poseidon and Jason altimeter data to construct a continuous record of mean sea level change. Marine Geodesy 27: 79-94.
Based on a review of ten years of satellite radar altimetry data the authors observe that the ongoing contribution of the Greenland and Antarctic ice sheets to sea-level is small. They point out that at the current sea-level-equivalent ice-loss rate of 0.05 millimeters per year, it would take a millennium to raise global sea level by five centimetres. At that rate it would take 20,000 years to raise sea levels by a single metre. In addition, They also report that the contribution of the ice sheets is small compared to the most recent estimate of current sea-level rise, which in their words, further confounds possible explanations of the causes of contemporary sea-level rise.
Morner, N. A., 2004. Estimating future sea-level changes from past records. Global and Planetary Change. 40: 49-54.
The author states that sea levels show no trend at all over three hundred years. Recent satellite telemetry shows virtually no unusual change in the most recent decade of measurements.
It is essentially impossible to discern a supposed human signal from the natural trends that have their own internal variability. These are just a small number of papers that deal with polar temperature measures or sea level rise.
There is an assumed understanding among those who argue that human emissions of C02 are the primary driver for climate change. In fact, the assumptions of the primacy and effect of C02 are overstated.
Ferguson P. R. and Veizer, J. 2007. Coupling of water and carbon fluxes via the terrestrial biosphere and its significance to the Earth's climate system. 112. D24S06, doi:10.1029/2007JD008431, 2007
In their paper, the authors show that the considerably larger global water cycle controls the much smaller carbon cycle, not vice versa. Geophysical studies have consistently shown that water vapour is the likely driver of both carbon dioxide and temperature. Any correlation between carbon dioxide and temperature can be viewed as an artifact of the “water cycle intermediary.”
There are many others like this, and on many other subjects related to climate. But frankly, I see no need to go on with this thread.
