How We Know Global Warming is Real
Dr. Tapio Schneider discusses the science behind human-induced climate change. He is a climate scientist and Professor of Environmental Science and Engineering at the California Institute of Technology.
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The Science Behind Human-induced Climate Change
Atmospheric carbon dioxide concentrations are higher today than at any time in at least the past 650,000 years. They are about 35% higher than before the industrial revolution, and this increase is caused by human activities, primarily the burning of fossil fuels. Carbon dioxide is a greenhouse gas, as are methane, nitrous oxide, water vapor, and a host of other trace gases. They occur naturally in the atmosphere. Greenhouse gases act like a blanket for infrared radiation, retaining radiative energy near the surface that would otherwise escape directly to space. An increase in atmospheric concentrations of carbon dioxide and of other greenhouse gases augments the natural greenhouse effect; it increases the radiative energy available to Earth’s surface and to the lower atmosphere. Unless compensated for by other processes, the increase in radiative energy available to the surface and the lower atmosphere leads to warming. This we know. How do we know it?
Figure 1. Carbon dioxide concentrations in Antarctica over 400,000 years. “The graph combines ice core data with recent samples of Antarctic air. The 100,000-year ice age cycle is clearly recognizable.” (Data sources: Petit et al. 1999; Keeling and Whorf 2004; GLOBALVIEW-CO2 2007.)
How do we know carbon dioxide concentrations have increased?
The concentrations of carbon dioxide and other greenhouse gases in atmospheric samples have been measured continuously since the late 1950s. Since then, carbon dioxide concentrations have increased steadily from about 315 parts per million (ppm, or molecules of carbon dioxide per million molecules of dry air) in the late 1950s to about 385 ppm now, with small spatial variations away from major sources of emissions. For the more distant past, we can measure atmospheric concentrations of greenhouse gases in bubbles of ancient air preserved in ice (e.g., in Greenland and Antarctica). Ice core records currently go back 650,000 years; over this period we know that carbon dioxide concentrations have never been higher than they are now. Before the industrial revolution, they were about 280 ppm, and they have varied naturally between about 180 ppm during ice ages and 300 ppm during warm periods (Fig. 1). Concentrations of methane and nitrous oxide have likewise increased since the industrial revolution (Fig. 2) and, for methane, are higher now than they have been in the 650,000 years before the industrial revolution.
Figure 2. Greenhouses gases then and now.
How do we know the increase in carbon dioxide
concentrations is caused by human activities?
There are several lines of evidence. We know approximately how much carbon dioxide is emitted as a result of human activities. Adding up the human sources of carbon dioxide — primarily from fossil fuel burning, cement production, and land use changes (e.g., deforestation) — one finds that only about half the carbon dioxide emitted as a result of human activities has led to an increase in atmospheric concentrations. The other half of the emitted carbon dioxide has been taken up by oceans and the biosphere — where and how exactly is not completely understood: there is a “missing carbon sink.”
Human activities thus can account for the increase in carbon dioxide concentrations. Changes in the isotopic composition of carbon dioxide show that the carbon in the added carbon dioxide derives largely from plant materials, that is, from processes such as burning of biomass or fossil fuels, which are derived from fossil plant materials. Minute changes in the atmospheric concentration of oxygen show that the added carbon dioxide derives from burning of the plant materials. And concentrations of carbon dioxide in the ocean have increased along with the atmospheric concentrations, showing that the increase in atmospheric carbon dioxide concentrations cannot be a result of release from the oceans. All lines of evidence taken together make it unambiguous that the increase in atmospheric carbon dioxide concentrations is human induced and is primarily a result of fossil fuel burning. (Similar reasoning can be evoked for other greenhouse gases, but for some of those, such as methane and nitrous oxide, their sources are not as clear as those of carbon dioxide.)
How can such a minute amount of carbon dioxide
affect Earth’s radiative energy balance?
Concentrations of carbon dioxide are measured in parts per million, those of methane and nitrous oxide in parts per billion. These are trace constituents of the atmosphere. Together with water vapor, they account for less than 1% of the volume of the atmosphere. And yet they are crucially important for Earth’s climate.
Earth’s surface is heated by absorption of solar (shortwave) radiation; it emits infrared (longwave) radiation, which would escape almost directly to space if it were not for water vapor and the other greenhouse gases. Nitrogen and oxygen, which account for about 99% of the volume of the atmosphere, are essentially transparent to infrared radiation. But greenhouse gases absorb infrared radiation and re-emit it in all directions. Some of the infrared radiation that would otherwise directly escape to space is emitted back toward the surface. Without this natural greenhouse effect, primarily owing to water vapor and carbon dioxide, Earth’s mean surface temperature would be a freezing -1°F, instead of the habitable 59°F we currently enjoy. Despite their small amounts, then, the greenhouse gases strongly affect Earth’s temperature. Increasing their concentration augments the natural greenhouse effect.
Figure 3. How We Know the Globe is Warming.
How do increases in greenhouse gas concentrations
lead to surface temperature increases?
Increasing the concentration of greenhouse gases increases the atmosphere’s “optical thickness” for infrared radiation, which means that more of the radiation that eventually does escape to space comes from higher levels in the atmosphere. The mean temperature at the level from which the infrared radiation effectively escapes to space (the emission level) is determined by the total amount of solar radiation absorbed by Earth. The same amount of energy Earth receives as solar radiation, in a steady state, must be returned as infrared radiation; the energy of radiation depends on the temperature at which it is emitted and thus determines the mean temperature at the emission level. For Earth, this temperature is -1°F — the mean temperature of the surface if the atmosphere would not absorb infrared radiation. Now, increasing greenhouse gas concentrations implies raising the emission level at which, in the mean, this temperature is attained. If the temperature decreases between the surface and this level and its rate of decrease with height does not change substantially, then the surface temperature must increase as the emission level is raised. This is the greenhouse effect. It is also the reason that clear summer nights in deserts, under a dry atmosphere, are colder than cloudy summer nights on the U.S. east coast, under a relatively moist atmosphere (Figs. 4 and 5).
Figure 4 and 5. Two Cheers for the Greenhouse Effect. Some global warming is necessary in order to make the Earth habitable for creatures like us. These two graphics show how it works. The IPCC caption reads: “Estimate of the Earth’s annual and global mean energy balance. Over the long term, the amount of incoming solar radiation absorbed by the Earth and atmosphere is balanced by the Earth and atmosphere releasing the same amount of outgoing longwave radiation. About half of the incoming solar radiation is absorbed by the Earth’s surface. This energy is transferred to the atmosphere by warming the air in contact with the surface (thermals), by evapotranspiration and by longwave radiation that is absorbed by clouds and greenhouse gases. The atmosphere in turn radiates longwave energy back to Earth as well as out to space.” Source: Kiehl and Trenberth (1997). (Graphics are FAQ 1.1, 1.3, Figure 1 from the IPCC Report.)
In fact, Earth surface temperatures have increased by about 1.3°F over the past century (Fig. 3). The temperature increase has been particularly pronounced in the past 20 years (for an illustration, see the animations of temperature changes). The scientific consensus about the cause of the recent warming was summarized by the Intergovernmental Panel on Climate Change (IPCC) in 2007: “Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations… The observed widespread warming of the atmosphere and ocean, together with ice mass loss, support the conclusion that it is extremely unlikely that global climate change of the past 50 years can be explained without external forcing, and very likely that it is not due to known natural causes alone.”
Figure 6. The History of Climate Models. The IPCC caption reads: “The complexity of climate models has increased over the last few decades. The additional physics incorporated in the models are shown pictorially by the different features of the modelled world.” (Graphic is Figure 1.2 from the IPCC Report.)
The IPCC conclusions rely on climate simulations with computer models (Fig. 6). Based on spectroscopic measurements of the optical properties of greenhouse gases, we can calculate relatively accurately the impact increasing concentrations of greenhouse gases have on Earth’s radiative energy balance. For example, the radiative forcing owing to increases in the concentrations of carbon dioxide, methane, and nitrous oxide in the industrial era is about 2.3 Watts per square meter. (This is the change in radiative energy fluxes in the lower troposphere before temperatures have adjusted.) We need computer models to translate changes in the radiative energy balance into changes in temperature and other climate variables because feedbacks in the climate system render the climate response to changes in the atmospheric composition complex, and because other human emissions (smog) also affect climate in complex ways. For example, as the surface and lower atmosphere warm in response to increases in carbon dioxide concentrations, the atmospheric concentration of water vapor near the surface increases as well. That this has to happen is well established on the basis of the energy balance of the surface and relations between evaporation rates and the relative humidity of the atmosphere (it is not directly, as is sometimes stated, a consequence of higher evaporation rates).
Water vapor, however, is a greenhouse gas in itself, and so it amplifies the temperature response to increases in carbon dioxide concentrations and leads to greater surface warming than would occur in the absence of water vapor feedback. Other feedbacks that must be taken into account in simulating the climate response to changes in atmospheric composition involve, for example, changes in cloud cover, dynamical changes that affect the rate at which temperature decreases with height and hence affect the strength of the greenhouse effect, and surface changes (e.g., loss of sea ice). Current climate models, with Newton’s laws of motion and the laws of thermodynamics and radiative transfer at their core, take such processes into account. They are able to reproduce, for example, Earth’s seasonal cycle if all such processes are taken into account but not, for example, if water vapor feedback is neglected. The IPCC’s conclusion is based on the fact that these models can only match the observed climate record of the past 50 years if they take human-induced changes in atmospheric composition into account. They fail to match the observed record if they only model natural variability, which may include, for example, climate responses to fluctuations in solar radiation (Fig. 7).
Figure 7. Global and Continental Temperature Change. The IPCC caption reads: “Comparison of observed continental — and global — scale changes in surface temperature with results simulated by climate models using either natural or both natural and anthropogenic forcings. Decadal averages of observations are shown for the period 1906–2005 (black line) plotted against the center of the decade and relative to the corresponding average for the period 1901–1950. Lines are dashed where spatial coverage is less than 50%. Darker shaded bands show the 5 to 95% range for 19 simulations from five climate models using only the natural forcings due to solar activity and volcanoes. Lighter shaded bands show the 5 to 95% range for 58 simulations from 14 climate models using both natural and anthropogenic forcings.” (Graphic is Figure SPM.4 from the IPCC Report.)
Climate feedbacks are the central source of scientific (as opposed to socio-economic) uncertainty in climate projections. The dominant source of uncertainty are cloud feedbacks, which are incompletely understood. The area covered by low stratus clouds may increase or decrease as the climate warms. Because stratus clouds are low, they do not have a strong greenhouse effect (the strength of the greenhouse effect depends on the temperature difference between the surface and the level from which infrared radiation is emitted, and this is small for low clouds); however, they reflect sunlight, and so exert a cooling effect on the surface, as anyone knows who has been near southern California’s coast on an overcast spring morning. If their area coverage increases as greenhouse gas concentrations increase, the surface temperature response will be muted; if their area coverage decreases, the surface temperature response will be amplified. It is currently unclear how these clouds respond to climate change, and climate models simulate widely varying responses. Other major uncertainties include the effects of aerosols (smog) on clouds and the radiative balance and, on timescales longer than a few decades, the response of ice sheets to changes in temperature.
Uncertainties notwithstanding, it is clear that increases in greenhouse gas concentrations, in the global mean, will lead to warming. Although climate models differ in the amount of warming they project, in its spatial distribution, and in other more detailed aspects of the climate response, all climate models that can reproduce observed characteristics such as the seasonal cycle project warming in response to the increases in greenhouse gas concentrations that are expected in the coming decades as a result of continued burning of fossil fuels and other human activities such as tropical deforestation. The projected consequences of the increased concentrations of greenhouse gases have been widely publicized. Global-mean surface temperatures are likely to increase by 2.0 to 11.5°F by the year 2100, with the uncertainty range reflecting scientific uncertainties (primarily about clouds) as well as socio-economic uncertainties (primarily about the rate of emission of greenhouse gases over the 21st century). Land areas are projected to warm faster than ocean areas. The risk of summer droughts in mid-continental regions is likely to increase. Sea level is projected to rise, both by thermal expansion of the warming oceans and by melting of land ice.
Less widely publicized but important for policy considerations are projected very long-term climate changes, of which some already now are unavoidable. Even if we were able to keep the atmospheric greenhouse gas concentration fixed at its present level — this would require an immediate and unrealistically drastic reduction in emissions — the Earth surface would likely warm by another 0.9–2.5°F over the next centuries. The oceans with their large thermal and dynamic inertia provide a buffer that delays the response of the surface climate to changes in greenhouse gas concentrations. The oceans will continue to warm over about 500 years. Their waters will expand as they warm, causing sea level rise. Ice sheets are thought to respond over timescales of centuries, though this is challenged by recent data from Greenland and Antarctica, which show evidence of a more rapid, though possibly transient, response. Their full contribution to sea level rise will take centuries to manifest. Studies of climate change abatement policies typically end in the year 2100 and thus do not take into account that most of the sea level rise due to the emission of greenhouse gases in the next 100 years will occur decades and centuries later. Sea level is projected to rise 0.2–0.6 meters by the year 2100, primarily as a result of thermal expansion of the oceans; however, it may eventually reach values up to several meters higher than today when the disintegration of glaciers and ice sheets contributes more strongly to sea level rise. (A sea level rise of 4 meters would submerge much of southern Florida.)
Certainties and Uncertainties
While there are uncertainties in climate projections, it is important to realize that the climate projections are based on sound scientific principles, such as the laws of thermodynamics and radiative transfer, with measurements of optical properties of gases. The record of past climate changes that can be inferred, for example, with geochemical methods from ice cores and ocean sediment cores, provides tantalizing hints of large climate changes that occurred over Earth’s history, and it poses challenges to our understanding of climate (for example, there is no complete and commonly accepted explanation for the cycle of ice ages and warm periods). However, climate models are not empirical, based on correlations in such records, but incorporate our best understanding of the physical, chemical, and biological processes being modeled. Hence, evidence that temperature changes precede changes in carbon dioxide concentrations in some climate changes on the timescales of ice ages, for example, only shows that temperature changes can affect the atmospheric carbon dioxide concentrations, which in turn feed back on temperature changes. Such evidence does not invalidate the laws of thermodynamics and radiative transfer, or the conclusion that the increase in greenhouse gas concentrations in the past decades is human induced.
This article can be found in
volume 14 number 1
A Climate of Belief
How We Know Global Warming is Real: The Science Behind Human-induced Climate Change; How to solve the global warming problem by 2020…
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I was going to subscribe to your site and newsletter, but I see you have no more rational way of dealing with belief-driven drivel than do people like Graham Hancock or Billy Graham.
Where’s your skepticism when we, the consuming public, need it the most? Why do you accept the test data as factual, when so many of the testing stations have been PROVEN to give fundamentally flawed readings? Why are you just accepting, as dogma, the IPCC reports? Where’s your healthy skepticism of the data?
By your standards, David Copperfield has harnessed the real power of magic because video cameras don’t lie.
How incredibly disappointing to see an article like this on a site that prides itself on its rational thinking.
Deniers attack the science by saying it’s flawed. Please point to the science that says their science is wrong. Please indicate where I can read the peer reviewed science that says the planet is not warming and that humans are not responsible.
I share Anthony’s disappointment in your lack of skepticism concerning the global warming issue. I just got done watching your admirable refutation of reincarnation on CBS’s “Sunday Morning” 15 May 11 show. Excitedly, I said to myself, “Here’s an organization/magazine that finally gets it, by using science to crush ridiculous hypotheses. Here’s a magazine that will look at the quality and weight of evidence on both sides of the argument, then make a logical decision. This is a magazine that I would buy.”
But before I was willing to purchase a subscription to Skeptic Magazine, I wanted to see what your stance was on my personal “litmus test,” which is the man-made global warming farse. The fact that you embrace the flimsy evidence of what is actually a “redistribution of wealth” scheme is very disappointing. I have studied the man-made global warming issue deeply, including the reading of the IPCC’s current and past reports. The “science” in their reports is very sloppy, and they actually undermine their own arguments in the earlier versions of their reports. For instance, they cannot adequately explain why the average global temperature was going down (not up) during the 1940-1975 period, when CO2 was rising sharply. They also claim that there was a warming period during the Middle Ages (when CO2 concentrations were obviously lower due to a less-populated, less-industrialized world). Interestingly, these two references were removed from subsequent IPCC reports.
Therefore, I will not be purchasing your magazine at this time.
“Extraordinary claims require extraordinary evidence.” — Carl Sagan
I agree and I am no longer going to subscribe to the magazine.
My MIT professor, Richard Lindzen was on the IPCC committee and disagreed with its conclusions. IPCC is dominated by politics, which is obvious given that it is Intergovernmental. The UN loves anything where it can get more power.
My personal question is: If the CO2 has risen so sharply, why hasn’t the temperature also risen sharply? If it had risen sharply between 2001 and 2011, it would be so obvious that we wouldn’t be having this discussion.
The increase in the temperature caused by CO2 happens over a timescale of a few decades, the change is moderate and not spread out evenly, the increased pressure in the north pole has sent cold air surging southward, cooling the areas around it and heating itself up.
There is no evidence that the slight warming trend since the 1850′s is accelerating or deviating from the long term trendline.
Patently absurd.
Temperature stations are known to be flawed, due to where they have been erected.
We now know that the data has been manipulated, via the HADCRUT emails and data sets contained in those emails.
Given the events that took place on December 26, 2004 and most recently in Japan, to even think that the modern human industrial population can cause the earth’s climate to change is patently absurd.
Computer climate models are fundamentally flawed, in that “scientists” are placing worst case scenarios into the software. Isn’t it obvious what the results will be? It’s called GIGO (Garbage In, Garbage Out).
Science demands that data is to be reproducible and verifiable in the present, not 10, 15 or 100 years in the future. If the local weatherman can’t be a hundred percent accurate for 5 days, what makes you think the bureaucrats at the IPCC can do it in a hundred years?
After reading this article, which smacks of Al Gore dogma, I fail to see even the slightest bit of skepticism.
“Temperature stations are known to be flawed, due to where they have been erected.”
What rubbish. There are tens of thousands of professionally-sited meteorological stations, plus hundreds of thousands of readings taken by other professional disciplines (e.g. Coastguards, ATC, etc.). Yes, you can find some poorly-sited instruments, but their contributions is *far* outweighed by data from consistently-reliable sites.
“Computer climate models are fundamentally flawed, in that “scientists” are placing worst case scenarios into the software.”
Can we see some proof of this accusation? If you understood weather and climate models, you’d know that models are constrained by climatology – e.g. if the rainfall in (say) Inverness had *never ever* totalled 500mm, then models won’t predict 500mm, even though that really would be a very damaging worst case. That is why forecasting centres still keep human forecasters. Models are accurate, but humans can improve on them just where we need it most – the worst-case scenarios. Climate change models, if anything, are not pessimistic enough, with regards to what is happening to the world’s climate.
” While there are uncertainties in climate projections, it is important to realize that the climate projections are based on sound scientific principles, such as the laws of thermodynamics and radiative transfer, with measurements of optical properties of gases. ”
The laws of thermodynamics are, it is plain to see for all,
mangled beyond recognition and reality in K&T and computer climate models.
ONLY in “greenhouseland physics” are such “laws” obeyed.
Somewhere between (real world) observation (and a lot of guesses)
a “mother of all averages” approach has been applied to an unphysical reality.
(Somewhere = incorrect / invalid conversion of Joules to W/m2)
“Certainties and Uncertainties” – you are having a patently divorced from reality laugh at our expense are you not.
Playstations and that type of virtual reality are for racing cars and mock battles,
NOT climate science.
And for those interested in the REAL science, you might try this:
“Although carbon dioxide is capable of raising the Earth’s overall temperature, the IPCC’s predictions of catastrophic temperature increases produced by carbon dioxide have been challenged by many scientists. In particular, the importance of water vapor is frequently overlooked by environmental activists and by the media. The above discussion shows that the large temperature increases predicted by many computer models are unphysical and inconsistent with results obtained by basic measurements. Skepticism is warranted when considering computer-generated projections of global warming that cannot even predict existing observations. ”
From here: http://brneurosci.org/co2.html
Water vapor is always ignored by these people, because taking it into account will always destroy their “science”.
Until they can reconcile how carbon dioxide can be a pollutant, when it’s a nutrient fertilizer, they have no argument.
Steve, your comment, “Until they can reconcile how carbon dioxide can be a pollutant, when it’s a nutrient fertilizer, they have no argument.” is completely absurd.
Lots of things that are “healthy” in “moderate” quantities can be poisonous/deleterious at higher levels.
You comment is similar to saying: “How can someone argue that oxygen can kill you when it’s essential for survival?”
Easily….try breathing in pure O2. You won’t be able to tell me the outcome of that experiment.
“Easily….try breathing in pure O2. You won’t be able to tell me the outcome of that experiment.”
That is really dumb Greg.
The subject is CO2 concentration.
Most of the existing plants today EVOLVED in much higher levels of CO2 than today.Have you even thought about that?
That’s an excellent article, Anthony.
Here is a reply at my forum on particular point in my simple counterpoint against this blog entry.It only covers on a small part.
http://www.globalwarmingskeptics.info/forums/thread-1153-post-8155.html#pid8155
It is a common error,that never seems to be noticed by those who embrace the AGW hypothesis.
Your very statement destroys your claim that CO2 is driving temperatures upward.I quote you,
“Atmospheric carbon dioxide concentrations are higher today than at any time in at least the past 650,000 years.”
But the chart you used to bring it up shows temperature range from the bottom the ice age phases to the warmest interglacial phases.While not shown on YOUR misleading chart.It is in the range of 15+C.
Not only that several peer reviewed papers published since 1999 (you never point out) shows that major CO2 trends changes FOLLOWS major temperature changes.The range is commonly 400 + years lagging.This means significant temperature changes goes first and CO2 follows later.
This takes away the unverified idea that CO2 drives up temperatures.It has also been shown that when temperatures are in a sustained downward trend,CO2 is still trending upward for a long while.
You also show an undue reliance in modeling simulations for supporting the AGW hypothesis.This is not valid science research.Not only that the IPCC allowed a lot of Grey literature or unpublished papers to be added in.This website covers it well:
http://nofrakkingconsensus.wordpress.com/2010/04/14/climate-bible-gets-21-fs-on-report-card/
The IPCC 2007 report did make a testable prediction that we would find the Tropospheric “hotspot” and a cooling trend in the Stratosphere.All based on modeling runs of course.
Unfortunately despite the pretty modeling runs that were supposed to make it real.Was not supported by Radio Sonde balloons and Satellite temperature data.
The Stratosphere stopped cooling in 1993.
It is a serious failure of the AGW hypothesis.Why did you not bring it up?
Here is my brand new report I just published on my forum that discussed it:
http://www.globalwarmingskeptics.info/forums/thread-1158.html
I see that sunsetommy has completely destroyed this article.
For shame, Michael Schermer….you should know better.
OMG. I used to have a great deal of respect for this site. How can you publish such a one-sided article?
In the aviation world, manufacturing to tight tolerances of +/- .0002″ is not uncommon. The ability to accurately and repeatedly measure a part required to meet this tolerance is of paramount importance. Quality control personnel need to select a gauge capable of measuring the part to the required tolerance while simultaneously assuring a discrepant part is not erroneously identified (through measurement) as being conforming and vice-versa. Welcome to the world of gauge capability studies.
Absent in ANY forum I have ever heard or read on the topic of global warming is any discussion about gauge capability. For example, let’s consider the temperature measurements taken in the 1840′s as presented in the Global Temperature Time Series chart included with the “How We Know Global Warming is Real” article and begin to ask basic questions. Keep in mind that we are trying to measure a small fraction of one degree Celsius (this seems to be important in the global warming theory):
1) Exactly what gauges were used to make the recorded observations and how were they maintained?
2) What were their respective tolerances?
3) Were the gauges all within calibration when their readings were recorded?
4) How was each gauge calibrated?
5) By whom were they calibrated and what standard was used to calibrate each gauge? (unlike today, I am unsure there was an agreed upon international standard for calibration like NIST for example, in the mid 19th century)
6) What was the calibration interval for each gauge and how was this determined to be adequate?
7) If from one calibration interval to the next a particular gauge was found to be out of tolerance, what procedure was used to call into question data recorded during the interval between the last known good calibration and the non-conforming calibration?
8) Was it the same operator recording the same data the same way every time? How repeatable and reproducible are the results and how was this validated?
9) As individuals who recorded data were rotated out, either through relocation, death, boredom, etc., how was the new operator technique verified and validated and how was any variation in technique factored into recorded values?
10) If training was required to accurately utilize a specific measuring device, did the recorder of the data displayed on a particular gauge receive that training? How do we know?
What I am driving at here is to question what has been accepted as axiomatic in global warming discussions; that the methods and procedures used to measure the data presented to support the theory is valid.
Dan, seemly legitimate questions, but have you ever heard of ice cores?
Let’s say for a hypothetical moment that we accepted AGW, what are the consequences of the projected temperatures rises? We’ve heard a lot from the ‘cataclysmics’ because bad news makes better press but surely there are positives too. If we accpet the inevitability of change surely we should be focusing on adapting to it, whatever its cause, and looking to take advantage for all life forms.
Good take as humans have an abysmal track record for predicting, forecasting, projecting, etc. (all euphemisms for “guessing”) and are much more adroit at adaptation.
No critical thinking in this article, just regurgitating the same rubbish that the IPCC, Wikipedia & the likes have been putting out
If we go to http://scienceandpublicpolicy.org/
we can find, among other things, this: http://scienceandpublicpolicy.org/images/stories/papers/originals/10_major_consensus_failures.pdf
Quote from introduction:
“”"We are going to ignore all the many ‘gates’ that were uncovered like the Himalayan glaciers, Amazon rain forests, how many real scientists there were who authored the key summaries and all the issues as to whether the summaries truly reflected the scientific information in the chapters and despite claims to the contrary, how a significant percentage of citations were not peer reviewed.
We will not attempt to address the issues of sensitivity for CO2 or solar and cloud and water vapor feedbacks relative to the models. We will also ignore the many model shortcomings – like inability to forecast regional patterns, ocean oscillations, etc. We will focus on how actual data compares to the consensus science, model based virtual world view of climate.”"”
And it shows simple DATA from REAL world!
After reading this data, one most definitely starts to question if Skeptic magazine takes sides issues if it involves politics. Human-induced warming equals Carbon Taxes, right?
Skeptic, you do good work with debunking witches and ghosts, and supernatural. Unfortunately, you seem to be mislead about global warming. Real skeptics know that they may be wrong at times. Real skeptics look closer at their own believes, question them, and print “sorry, I was wrong”.
It is very unfortunate that the term skeptic has been co-opted by people who are in denial of the evidence for anthropogenic climate change.
The modern climate-”skeptic” movement is being driven by extreme conservative ideologues. This movement is incredibly dangerous, as it is stridently opposed to building a more resilient society. These types of people have been at the core of civilizational decline since the earliest states and empires.
The un-adaptability of societies has been identified by a number of historians as one of the key reasons for societal collapse. If we refuse to even accept the idea of adaptation to a rapidly changing environment, then we are in for some serious trouble.
In any event, it is clear that many, even among those who consider themselves “skeptics” in the sense promoted by this society, have no intention of looking at the scientific evidence for the high certainty of anthropogenic climate change, so there’s no use discussing it.
This sounds like one of those logical fallacies that Shermer cautions his readers to watch out for. Don’t try to discredit the people on one side of the arguement from a political perspective. This is about evidence.
You are a funny guy Frank.
You badmouth people who are Skeptics.But ignore posted comments right here in THIS thread.That are based on climate science.My posts 7 and 8 was based on the authors own data and the IPCC.I was able to show why they were wrong.Using their own favored data.
I run a climate skeptic forum,probably the largest in the internet.I never got any of that much blabbed about “oil” funding.Or be awarded a bogus big dollar prize.Maybe YOU can send me some money?
There,AGW believers are too chicken to join or even post in the guest forum.I KNOW that Joe Romm,Gavin Schmidt and a few warmists have visited.Ok So John Cook did make a guest post.But never comes back to make replies.To our comments.
Anyone who thinks CO2 “Traps” is really seriously out of their minds.The demonstrated fact is that CO2 molecule absorbs and emits in a very narrow frequency in less than a tenth of a second.Or conducts the energy in molecular collisions (which is more common than radiating it away) with other atmosphere gases.Most commonly N2 and O2.
Again there is no compelling evidence of any AGW going on.
The evidence has been debunked. The many models do not produce the same results. This was admitted in a recent (may 10) study concerning tree ring records.
If the models cannot predict El Nino effects which “cause climate extremes” with absolutely no confidence: “Current models diverge in their projections of its future behavior, with some showing an increase in amplitude, some no change, and some even a decrease.” They are absolutely 100% invalid.
“Since El Nino causes climate extremes around the world, it is important to know how it will change with global warming,” says co-author Shang-Ping Xie.
“Current models diverge in their projections of its future behavior, with some showing an increase in amplitude, some no change, and some even a decrease. Our tree-ring data offer key observational benchmarks for evaluating and perfecting climate models and their predictions of the El Nino-Southern Oscillation under global warming.”
one of many appearances of the article:
http://www.terradaily.com/reports/Tree_rings_tell_a_1100_year_history_of_El_Nino_999.html
I also came here looking at whether I would subscribe to an organization that otherwise seems to make a lot of sense.
I was shocked with a simple search to see that there appears to be no skepticism here about AGW!
I want go into the detailed arguments repeated by many here, but surveys of climate skeptics and AGW proponents show consistently higher IQ levels amongst skeptics. It is unclear why an organization like this would allow the clearly less intelligent post such biased and badly documented arguments.
Shame. Time for someone to found a real society for skeptics.
Hello ladies. AGW is on the line.
You know how bad it is out there? After days of recognition:
— Forum closed beacuse of abuse.
— Discussions with long rails of arguments with links leading nowhere.
— Arguments so low, I would insult even the worst of us here even spelling one single letter of it.
— This website seems a fair one. Thank you.
SUBJECT
Tom H, Don, and all (above) others observed in »the Quiet Hot, Discarded, Forgotten Desert» out there:
— Your questions are just;
— Provided we accept the given measured NASA temperature curve (link below) as the only adequate proof of global warming: You are mislead:
— Deniers, skeptic, claim THIS (short illustration to you, with already well known given established sources)
http://www.universumshistoria.se/AAAPictures/AGW1.htm
NASA-CURVE COMPONENT EQUIVALENT
— the dotted (industry + sea period) over the solid measure
— matching any precise PREDICTIVE POWER we need, all the way from 1860 till now, and hence further, [small] additive components from the effect itself omitted
doesn’t hold — that it is a »hoax» and a »scam»:
— The reason asked by Tom H and Don, and others, is easy to see directly;
— It is the periodic part from the sea period that gives smaller troughs and crests; these smaller deviations (now a cooling one until ca 2016) are the reason why the layman is confused, favoring analogies to »a warming trend»: any »warming trend» seems to have vanished.
— Fatally (due to »many friends») the skeptic becomes a denier, collecting a tail of »screamers» having their own industry on »hoax», »scam» and »fraud» — until truth is revealed: AGW holds in exceptional detail.
As you can see from the match — same power of predictability as can be seen all the way from 1860:
— About two decades ahead, the climate will level about the same as it is now (2011): two minor troughs follow at 2018 and 2038 with one minor crest in-between at 2025 (the preceding at 2005); From 2038 a steep rise will follow (up to ca 2070) of the same nature as the one 1972-2005 (called »The Great Pacific Climate Shift»*), which apparently will speed up the global warming — perhaps beyond all further achievable rejective control.
IF people will witness such a global climate history (which I hope they will not), those in our special concern today compared with theirs will (most probably) be a play in the teagarden (also given in an answer on Yahoo).
*page 1 bottom of
http://icecap.us/docs/change/OceanMultidecadalCyclesTemps.pdf
ADDITION — SHORT BACKGROUND
— On the preciseness of the percept of the equality of components (dotted compared to solid), making up the measured NASA global warming curve, I must (only on my account), in some sense, give you skeptics (but not deniers) right (»emotionally») — by strict mathematics:
— The mathematical analogy to the shown equal (by two, industry Fossil-Carbon + sea period) components
— including the set of seven (7) functional curves (derivatives, integrals) that must fit into the total picture
(including a final Carbon-Dioxide table with values matching the measured to within 98%)
— has nowhere, at no place, an expression for the Planck radiation law.
— It’s not there — but the established models all build upon that one (they are also included by comparison and examples in the general description of the match, [possibly] explaining why the Planck law is not needed there).
— Planck radiation law math has nothing to do with explaining the global warming phenomena — as measured during the 20th century: Its calculation is never used in the above exemplified match. Its formula is never mentioned nor consulted.
— Why is that? That is because the industrially (Anthropogenic) triggered Global Warming (AGW) has no such mathematical-physical connection to explain for the net effect: Not at the driving energy side, not at the distributing effective side — even if such components exist along (these are negligible).
— The complex shows a pure thermodynamic resistive picture of a (complex) heat dump [with Solar interference] of industrial energy-temperature into the oceans by a net height of just 50 meters (calculated result) above land-marine geography, taken during a longer period (150 years) by small daily amounts of additional carbon emissions: steady minute by minute. It’s all caused by man made industry from fossil carbon, as you can see from (the two component equivalent) the dotted predictive match to the solid measured NASA-curve.
— Carbon-Dioxide concentrations resulting from the calculations agree with the measured values within 98%; Every atom of this global warming story during the 20th century is industrial fossil carbon. Exact, precise, clear.
wkg/Guinnevere
The question debated has never been is AGW legitimate, but rather how much do humans contribute to the warming trend. Is it negligible? Is it the majority? 20 percent? 80 percent? Or somewhere in between? Obviously, I agree with the latter statement, but where does it fall? That is what the argument is all about.
“If the local weatherman can’t be a hundred percent accurate for 5 days, what makes you think the bureaucrats at the IPCC can do it in a hundred years?”
I can’t say if you might die in the next 5 days, but I’m sure you won’t be around in 2111. Looking at short-term and long-term are 2 totally different things.
To forecast weather, you need to know what’s happening right now to temperature, moisture, wind, etc. You can project that forward, but that current information has less and less relevance as time progresses. To forecast climate in a world where greenhouse gases are increasing in 2011, all you need to know (or estimate) is “How much more of those gases will there be in year 2011+X?” Double? Triple? Quadruple? or Worse?
Thank you. People don’t seem to realize that climate and weather are two completely different things. Climate is a trend. Weather is instantaneous.
Climate is composed of a series of weather events.
They can not separated from each other.They can not exist without the other.
Climate is about trends. It’s like looking at the stock market and saying “the Dow can’t be up, all my stocks are down!”
A magazine named Skeptic on board with AGW? This is a joke, right? I’m supposed to plop down 70 dollars for 3 years of this drivel. Change the name to “Sucker” magazine.
Skepticism doesn’t mean you never believe in things, it means you don’t believe in things without good reason.
Penn Jillette put it this way: “‘Nobody can convince me?’ Bells should go off in your head when you hear those words. That’s his bullshit idea of skepticism. A real skeptic *demands* to be convinced – with evidence.”
I don’t have any problem with the science if AGW turns out to be false, but it has to be backed with good evidence. It’s dangerous to fall back on the null hypothesis that if current climate science on AGW is bad, then there’s no problem.
For just a moment, put aside all the science, all the counter-arguments, rants and ravings. We, as a race, simply cannot continue pouring billions of tons of refuse into the environment without consequence. Have you ever visited your local dump? It does give an incredible sense of perspective on how poorly we have acted and continue to act as a species. There is absolutely no doubt that pouring so much garbage about, consequence of our galloping consumerism, impacts our environment. You can trot out models and counter-models but the message is simple and clear: we are destroying ourselves. While too many of you are busy closing your eyes and refusing to work toward a more sustainable future, some of us are pointing fingers at you saying: “Where is your contribution to making things better?” Counter-arguments serve an effective purpose in science however where is your proof that what we are doing to the planet, all of actions, causes no harm?
I was as shocked as most of the above respondents at seeing this totally unscientific article on a skeptic web-site. Is skepticism so selective? I too am very disillusioned.
The article just makes claims with no evidence, no references, no mention of contrary evidence, no mention of alternative arguments, no mention of model prediction failings etc. IOW it contravenes entirely the scientific requirements expressed elsewhere on this blog.
Bye, bye. Murray
What a joke. I was going to subscribe until I read this. Sounds like the “real skeptics” have commented and rejected your blog post.
At first I thought that this was an april 1st post.
For an honest attempt at pointing some obvious flaws, check out
http://lrak.net/globalwarming.htm
Its a brilliant article, IMO.
Also, NASA refutes much of the models’ assumptions on humidity:
http://www.nasa.gov/centers/goddard/news/topstory/2004/0315humidity.html
I’m not going to claim to be the skeptic’s skeptic, but I still have trouble with just swallowing the AGW pill. I think several things are being “missed” or ignored by those to pushing the GW issue as solely man’s fault.
We still do not know all the facts and intricacies of our biosphere. Do we have an impact? Yes. Is it to the scale that they say? Hmm?
The largest object in the solar system is the sun at a mere 99%, it goes through cycles. I’ve read in astronomy articles that the average temperature on mars has increased ay a degree or two. Man? CFCs whipped into space and pushed out to the martian orbit? In open space, exposure to direct sunlight will subject you to 250 degrees F. It’s nowhere near that anywhere on earth. (Even if it might feel like it sometimes.) Obviously the atmosphere blocks a lot of that radiation as well.
There is too much vested interest by scientists and universities to get funding; a sad fact in a society that venerates sports and media more than science. There is also too much arrogance and elitism within the science community to be ignored, many scientists hated Carl Sagan for “dumbing down” science so that the layman can understand it and become excited. At one time the world was flat, and the center of the universe. (I guess that’s true in an infinte universe, but then so is everywhere.) Einstein once backed the static earth view, turns out, like the meteor that wiped out the dinosours (also thought a myth), plate tectonics does exist. If one of the more brilliant men in science can be mistaken, can’t the “experts” be as well?
“Climategate” clearly demonstrated that some scientists won’t share the data. Why? If you fully believe what you say, then share. People have had to sue (and won) to get the data released under the UK’s FOIA. Again, why? If you’re so confident, then make the data available. It’s called peer review, not “pal review.” That’s the only way science improves. Douglas Adams’ character, Wanko the Sane, said it best, “If a scientist sees something, he must say he sees it. Otherwise he will only see what he expects.”
Reading Superfreakonomics puts a new light on what’s going on. A volcano explodes and the world’s temperature drops by a couple of degrees. I think mother nature has a far larger impact than we do.
Back to Climategate, comments in the code on what to change to produce the desired results is a clear indication of the faulty thinking of AGW pushers. Finding one anomalous tree in 10,000 that produces the “hockey stick,” then basing your entire thesis on it takes a leap of faith. For faith I look to religion, for truth I look to philosophy, for facts I look to science.
For those surprised by this article, I encourage you to overlook a “mistake” and subscribe. It is a very good society.
Oh dear! Farce not farse
Sea levels are rising. You can see the changes in Dunedin and along the Otago coastline. The increase is not huge but it magnifies the surges. Glaciers are receding in NZ. I should know. I have been tramping and climbing for 50 years. Temperatures are rising. Frosts and snows are now unusual events in Dunedin. Yet solar output has not changed significantly. It is deeply disturbing but denial (a common response) is not the answer.
If the deniers who have posted were honest, they would admit that they were never interested in subscribing to Skeptic Magazine. They are trolls who keep a lookout for any mention that global climate change has anything to do with human activity, and then they blast the comments with scientific-sounding garbage to confuse the issue of what skepticism is really all about – the quote by Penn Jillette above being right on the money.
I experienced this when my husband had the gall to post an article about the professional climate science denier who was funded by the Kotch brothers (I don’t recall his name) which mentioned the London Fog that existed back at the hight of the industrial revolution’s spewing of pollutants into the air unabated on a website about expatriation. Suddenly, our readership was filled with experts on how wrong all the other scientists were and that global warming is obviously due to sunspots. We were also instructed to not bring up the matter again because it is “too controversial.”
I am not a climate scientist myself, but someone who has been familiar with satellite studies of arctic ice flows because a good friend from engineering school was writing software for programs that do this for Jet Propulsion Labs decades ago (long before Al Gore or the attempt to find a market solution through carbon trading because convincing the powerful dirty oil, gas, and coal companies to spend a small proportion of their vast profits on cleaner technology was like talking to, well, a climate denier about real science came onto the scene) and I studied just enough physics, engineering, and math to understand how science works, as opposed to how the deniers keep claiming that it works.
So when a climate scientist weighed in about core samples, and I see the same point being made here, it really makes me wonder what climate science deniers have to say about the unrefutable evidence that is gleaned from these core samples. They never address this issue. Hmmm, I wonder why.
How would you cite this article? In MLA newest addititon?
This is my first visit to Skeptic via a Richard Dawkins video. I’m a sceptical layman but am also a bit… gullible. So what to conclude? The article is not independently analytical as I would have hoped and the sceptic comments and links have not really convinced me against AGW.
I’ll remain on the fence for now since I get the best view from here.
Wow, just because you disagree with someone means that they aren’t a skeptic. Interesting concept.
Anyone who argues that the planet is not warming has their head in a hole. Anyone who argues that CO2 is not increasing also has their head in a hole. More than a decade ago, it was shown that the isotopic carbon ratio of the additional CO2 matches the prediction made by the anthropomorphic hypothesis. This is mentioned in the article, but not with enough fanfare. This really is the silver bullet to deniers and I don’t know why it’s not mentioned more often.