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Posts Tagged ‘Greenhouse Effect’

Climate Change: Science and Solutions

Thu ,21/04/2016

This presentation was given at the Great Plains Conference on Animals and the Environment at Fort Hays State University for Earth Day 2016.  The first part of the program presents the evidenceccl1 for climate change and explains the urgency for taking action. The second part of the presentation explains the Citizens’ Climate Lobby’s  proposal to reduce our carbon emissions below 1990 levels by 2035.  The plan, with broad bipartisan support, would place a fee on carbon at the source and allow market forces to encourage reduced emissions, energy conservation and investments in renewable energy.

Science and Solutions 

Please click on the link above. You will need a PowerPoint program to view the slides – or you may  download a free viewer here. The slides will display as set in your viewer. The slides were meant to be somewhat self-explanatory, but if you have questions you may email the author or post your questions in the comment section. The slides were  prepared by Darrel Hart, Mark Shobe, and J.C. Moore.

PowerPoint Presentation: The Science of Climate Change

Tue ,14/07/2015
This was taken from Apollo 11 as the Earth rose over the disc of the Moon.

This was taken from Apollo 11 as the Earth rose over the disc of the Moon.

 

 

 

2015x-(3) The-Science-of-Climate-Change with notes

Please click on the link above. You will need a PowerPoint program to view the slides – or you may  download a free viewer here. The slides will display as set in your viewer. Explanations of the slides are in the notes section.

Media Bias: Why the Public Is Confused about Climate Change

Mon ,16/12/2013

The Tulsa World article ,”Global warming poll finds broad divide more political than scientific,” attempted to explain why the public and politicians are confused, not only about the issue, but about what scientists think.  Polls of climate scientists find a strong consensus on the issue , with  97 percent of scientists actively engaged in climate research agreeing that man’s activities are the main cause of global warming. Fearing a loss of profit if CO2 is regulated, there has been a well-funded effort to spread doubt about the scientific consensus. And some media sources are willing accomplices.

 The media has helped spread the doubt by treating the issue as a legitimate controversy, when there is very little controversy among scientists. At one time the Tulsa world was courageous enough to point out in an editorial that it was scientists who say that global warming is real and politicians who say that it is a hoax. However, the Tulsa world has changed ownership and the new managing editor has adopted a bias which he calls “reflecting Oklahoma values. “ The Tulsa World often publishes comments from readers in its editorial page, and though there were a number comments reflecting the scientists’ viewpoint, the editors added to the confusion by publishing only two comments from one side, and none representing scientists.

One comment tried to explain away the strong consensus among scientists by claiming that scientists find what they do because of money the research generates. However, climate and weather research is vital to our national interest and would be funded no matter what the scientists found. Climate scientists usually work at universities and government laboratories, where salaries range from $50,000 to $120,000. Research grants are awarded on a competitive basis, and most of the money from the grants goes for research expenses and little to the scientists. Their published results are held to a high peer review standard to ensure that the methodology is sound and the conclusions are consistent with the evidence. The amount of money they get is certainly not worth taking a chance on ruining their reputation and career.

The second comment claimed that the Earth’s systems are just too complicated to understand, and therefore climate scientist can’t know what they are talking about. That is the old Skeptic’s argument that if you don’t understand everything, then you understand nothing. In spite of the complexity, scientists have been able to identify the main factors that affect our climate. Greenhouse gas theory was developed in the 19th century, and after examining the natural and human caused factors that affect our climate, climate scientists have concluded that the main factor in global warming is man’s release of CO2.

The human body is also very complex, but medical scientists have identified a major risk factor to health be smoking. Yet, for many decades, tobacco companies were able to deny the scientific evidence that showed the link between smoking and coronary disease. Climate scientists have identified the major risk factor in climate change to be man’s emission of CO2 and warn of the danger to the environment that sustains us. However, like smokers who ignore their doctors, many people are unwilling to listen to the scientists’ warning. Would the Tulsa World, and other media sources, now be willing to treat the dangers of smoking as a legitimate controversy?

(c) 2013  J.C. Moore

 

Climate Change: A Letter to Congressman Lucas

Sat ,07/12/2013

This is a letter I sent to Congressman Frank Lucas (R – OK) on August 5, 2013. I asked him at his town hall meeting on November 7, 2013 if he had received it, and he could not recall it. It was a 15 page letter which contained anecdotal evidence plus the latest evidence from climate research in full color pictures and graphs. In case he misplaced it, I have reproduced the letter here in hopes he might run across it while looking for my write-up on his town hall meeting. It would seem that this information would be of vital interest to him as he is Chairperson of the Agriculture Committee, charged with the security of our food supply. 

 

Dear Congressman Lucas,

I’m sure you’re aware of the Pearson drought index which shows that most of Oklahoma, much of the Southwest United States, and much of the Earth’s land area where food is grown  is under moderate to severe drought conditions. It seems that lately the coastal areas of continents have been receiving more rainfall while the interiors have been experiencing more drought. I’ve lived in Oklahoma most of my 70 years and in my recollection, it seems that we are now seeing heavier rains in the spring and longer and more frequent droughts in the summer.

  My family has lived in Oklahoma since statehood and I have a number of anecdotes about how the climate is changing. Our Thanksgiving family photo in 1998 was taken in front of one of my Dad’s apple trees, which still had green leaves. He remarked at the time that he had never seen frost come so late, and he was 88 at the time. A few years ago our plant hardiness gardening zone was changed from a 6 to a 7, acknowledging later frosts and warmer winters. Armadillos are now abundant in Oklahoma, though there were none here when I was growing up.

 Anecdotes do not serve as proof, but they do raise questions about what the theories and evidence is saying. The greenhouse gas theory is solidly based upon the laws of physics. Though greenhouse gases comprise only 1 to 3% of the atmosphere, depending on the humidity, they are responsible for the Earth being about 33°C warmer than its would be without them. It seems reasonable that an increase in the greenhouse gases would cause the Earth to warm. Though water is by far the most abundant greenhouse gas, its concentration in the air is limited by its saturated vapor pressure. Carbon dioxide, though less abundant, absorbs strongly in the infrared and is not restricted in concentration as water is. Studies of the ice ages have identified carbon dioxide and changing solar irradiance as being the main factors in determining the Earth’s temperature.

 We are now putting about 30 billion tons of carbon dioxide into the air each year and measurements show that the concentration in the air is increasing. The increasing partial pressure of CO2 is causing more to dissolve in the oceans, decreasing their pH by about 0.1 pH unit.  That doesn’t sound like much, but the oceans are a carbonate buffer system and that translates into the oceans now being more than 20% acidic, threatening, shellfish, corals, and the plankton which convert much of the ocean’s carbon dioxide back to oxygen.

Biologists have observed that some species are migrating northward and to higher altitudes. There is evidence that glaciers are receding and that ice at the poles is declining. The declining extent of sea ice in the Arctic seems to be affecting the jet stream, which greatly affects our weather patterns. Though it is not possible to prove that global warming is the cause of any one weather event, it likely has an effect on most of the weather events that do occur, since the amount of energy and moisture in the air are the main determinants in weather events.

 There are always uncertainties in scientific measurements, and even greater uncertainties in predictions about the future. It is always possible to dispute any one piece of evidence based upon those uncertainties, but when a large number of independent measurements lead to a similar conclusion, the confidence level increases – but never reaches 100%.  I hope you will examine the evidence presented in the rest of this letter and agree that the preponderance of the evidence shows that we should take some action to address climate change.

 Republicans have a history of being strong advocates for science, environmental responsibility, and sound fiscal policy. Nixon created the EPA, Reagan signed the Montréal protocol limiting fluorocarbons and used cap-and-trade to reduce greenhouse gas emissions blowing into Canada, and archconservative Barry Goldwater once said that, ” The persistent myth that conservation and environmental protection are liberal causes continues to be perpetuated by the media, liberals and many self-professed ‘conservatives’. The truth is that conservation and environmental stewardship are core conservative values”.

 I hope you will examine the evidence presented in the rest of this letter and consider taking a leadership role in addressing the climate change issue in a manner that is consistent with Republican principles. In many ways, the world’s food supply is at risk.

The rest of the letter contained the images and descriptions from this article: http://jcmooreonline.com/2011/08/31/bits-and-pieces-10-global-warming-in-pictures/.

(c) 2013 J.C. Moore

Global Warming: The Role of Water Vapor

Sun ,20/01/2013

The Earth’s Temperature: Certainly, the average temperature of the Earth has varied greatly over the last million years, from about 2°C (36°F) during the ice ages to about 15°C (59°F) during the warmer interglacial periods. We are now in an interglacial periodic and the Earth’s average temperature for the last century averages 13.9°C (57°F). Much of the research on the Earth’s temperature has been an attempt to understand the coming and going of the ice ages. We now know that the Earth’s temperature is correlated with the Milankovitch cycles , which affect how much sunlight the Earth receives, but that is not the whole story. That greenhouse gases play a role in warming the Earth was shown by Joseph Fourier in the 1820s. Using the differential equations he developed for heat transfer, Fourier calculated that the Earth, considering its size and its distance from the Sun, should be considerably colder than it actually is. He proposed the Earth must be kept warmer by its atmosphere, which acts much as the glass in a greenhouse. The actual amount of warming that could be attributed to the greenhouse effect was later found from the Stephen Boltzmann law, developed in the early 1900s. If the Earth had no atmosphere, its average temperature would be 33°C  lower, at -19.0°C (-2.2°F). Without greenhouse gases, the Earth would be a frozen block of ice.

Greenhouse Gases: Heat energy leaves the Earth as infrared radiation, which makes up a part of the spectrum that is absorbed by many molecules as they vibrate. As infrared radiation leaves the Earth, it is absorbed then reemitted in all directions, some of it going back toward the Earth where it further warms the Earth. In the 1850’s, John Tyndall’s infrared research found that nitrogen and oxygen, the major components of the atmosphere, do not absorb infrared radiation. He discovered that the molecules responsible for the greenhouse effect were water vapor and carbon dioxide. Water varies from a trace up to about 4% depending on the humidity; carbon dioxide’s concentration was about 0.0028% in Tyndall’s time. In spite of their low concentration, CO2 and H2O both absorb strongly in the infrared region of the spectrum. Also, radiation leaving the Earth must traverse several kilometers of atmosphere, greatly increasing the probability of the radiation being absorbed and readmitted. Carbon dioxide plays a large role for its concentration, as it absorbs strongly in regions of the infrared spectrum where water does not.

Recent research by Kiehl and Tenebreth on the Earth’s energy budget identified five naturally occurring gases that contribute to the greenhouse effect. The gases, along with their contribution in both clear sky and cloudy conditions, are listed in the table.The infrared spectra of the major greenhouse gases can be found at http://chemlinks.beloit.edu/Warming/pdf/greenIR.pdf .

GasesEach of the greenhouse gases has several absorption bands, and there are some regions of the spectrum where the bands overlap, as noted in the table. Once clouds form, the liquid droplets absorbed broadly across most of the infrared region, so cloud formation reduces the contributions of the other gases. Overall, clouds and H2O account for about 75% of the greenhouse effect and carbon dioxide and the other greenhouse gases for about 25%. Some of the coldest nights on Earth are when the humidity is low and the night is still and clear, as the contribution of H20 is reduced far below the 60% given in the table.

The average residence time of a water molecule in the atmosphere is only about nine days. Because precipitation removes water from the air in such a short time, the concentration of water in the air varies from a trace in cold arid region up to about 4% in warm humid regions. The average residence time in the atmosphere of CH4 is 12 years, while the residence times of NO2 and CO2 are more than a century. Gases with long half-lives reside in the atmosphere long enough to become evenly distributed throughout the atmosphere.  Ozone (O3), which has a residence time of a few months, is constantly beingformed in the atmosphere from photochemical processes, many of which are initiated by methane and hydrocarbons.

The Limit of Humidity:  The pressure of the atmosphere is made up of contributions from all the molecules in the atmosphere and the share that each gas contributes is called its partial pressure. The amount of water in the air can be measured by its partial  pressure. There is a limit on the amount of water the air can hold as the humidity becomes 100% when the partial pressure equals the saturated vapor pressure, and the air can hold no more water.

VP1

The Saturated Vapor Pressure of Water

The saturated vapor pressure depends only on the temperature and is listed in the table at the right.That limit of water in an air mass can be reached by water evaporating from the surface until the partial pressure reaches the saturated vapor pressure given in the table. Alternatively, the limit can be reached when a mass of air is cooled until its saturated vapor pressure is lowered to the air’s partial pressure. Any further decrease in temperature will cause air to be oversaturated and cloud formation and precipitation is likely to occur. For example, at the equator, where the temperature averages 26°, water will evaporate until it reaches the  saturated vapor pressure of 25.2 mmHg. However, over the Arctic Ocean where the temperature averages 1°C, the air is saturated at 4.9 mmHg. Not surprisingly, the air can hold almost 5.1 times as much water at the equator. Or, on a clear night, when the temperature drops until the saturated vapor pressure is less than the air’s partial pressure, dew will form. The weatherman usually reports the temperature when that will happen as the “dew point”.

 CO2 Controls the Temperature: One of the great mysteries confronting science in the 1800’s was the cause of the ice ages. The role that greenhouse gases had in keeping the Earth warm provided a clue for Arrhenius, who thought that changes in their concentration might be the cause of the coming and going of the ice ages. He set out to find the climate sensitivity, the temperature change expected if the concentration is doubled, for the individual greenhouse gases. Arrhenius understood that the concentration of water vapor in the air was limited by its saturated vapor pressure, which is dependent on the temperature. How then, could an increase in H2O increase the temperature when it was itself limited by the temperature? Carbon dioxide has no such limitation, so Arrhenius turned his attention to finding the climate’s sensitivity to carbon dioxide. Though Arrhenius’s model was simple and the calculations were laborious, he found that doubling the carbon concentration would increase the temperature of the earth by about 5°C. However, the increase in temperature would allow a greater concentration of water vapor in the air which would amplify the warming. Thus, the concentration of CO2 acts as a regulator of water vapor, and ultimately determines the planet’s long-term equilibrium temperature. Recent work using better data and models have found that the climate sensitivity to carbon dioxide is in the range of 3 to 4°C, and carbon dioxide has been proposed as the “control knob” for the Earth’s temperature. Still, water vapor and clouds contribute the most to greenhouse warming, and their contribution is considered to be a positive feedback to the increasing carbon dioxide concentration.

No one in Arrhenius’s day could imagine how the atmosphere’s carbon dioxide concentration could possibly double, and some of Arrhenius’ contemporaries proposed setting some poor quality coal seams on fire to ward off another Ice Age. That proved not to be unnecessary as in 1900 Arvid Hgbom, a volcanologist, calculated that industrial sources were adding CO2 to the atmosphere at roughly the same rate as volcanoes. No one thought much of it as, at that rate, it would take centuries for the amount of CO2 to increase significantly. However, no one imagined that we would burn fossil fuels at today’s rate, putting 30 billion tons of CO2 into the air each year. The amount of carbon dioxide in the air has increased by 40% since Arrhenius’s day, and the temperature of the Earth has increased by about 0.85°C, well in line with Arrhenius’s predictions.

Alternate Theories: There are a number of alternate theories as to why the Earth is warming, and most of the recent ones center around water and clouds, as that is still an active area of research. The most easily dismissed one is that water vapor is responsible for global warming rather than carbon dioxide. Arrhenius showed that was false over 100 years ago, yet some Skeptics are still saying it. Another theory, credited to Svensmark, is that cosmic rays from the stars produce charged particles that promote cloud formation. There is little evidence that the cosmic rays reaching Earth have increased and there are plenty of particulates in the air to seed clouds besides the charged particles.  Another theory is Iris Effect which has been promoted by Richard Lindzen, mostly in op-ed pieces that are not peer-reviewed. His theory is that the earth’s sensitivity to greenhouse gases is low as the increasing  surface temperature at the equator will cause the rising columns of moist air to  rain out more moisture, leaving less to form high ice clouds, known to be a positive forcing. Aside from the fact that it seemed a little unreasonable to claim that more moisture in the air will lead to fewer high clouds, other climate scientists have found significant errors in Lindzen’s published works.

 A recent paper in Remote Sensing by Roy Spencer attributes global warming to cloud formation and it was claimed to “blow a gaping hole in global warming theory.” Its main theory was that clouds were driving global warming, rather than being a feedback mechanism. The paper was quickly refuted by climate scientists by pointing out that Spencer’s model of the Earth’s atmosphere was terribly inadequate. There is also evidence that Spencer’s paper gained publication by gaming the peer review system. Another theory comes from Roger Pielke Jr., who claims that hurricanes and tornadoes are becoming less frequent and destructive, based on an economic analysis of storm damage. Global warming is likely to increase the probability of severe storms, so his work has been used to discount global warming. However, his theories stand in sharp contrast to the number of events and the amounts paid out in storm damage  by Munich Re (the fourth and fifth graphs) , a large secondary insurance company, that analyzed the issue without the benefit of some of Pielke’s assumptions.

The final theory, which would be laughable if it weren’t repeated by many Skeptics to discredit climate science, is that climate scientists have created the CO2 global warming theory purely for their own economic benefit. The greenhouse gas theory was developed, and the main points understood by the end of the 19th century, long before any of today’s climate scientists were even born. Fourier, Tyndall, and Arrhenius established that H2O and CO2 were main factors in warming the earth, with changes in CO2 concentrations being the primary driving force and H2O being a feedback to changes in the CO2 levels. Research since then has confirmed their findings, and their theories have been borne out by the global warming we have experienced since their day. It is hard to believe that any credible scientist would reject such well-established theories.

Note: Much of the historical data in this article came from http://www.aip.org/history/climate/co2.htm

(C) 2013 J.C. Moore

The Skeptic's Guide to the Medieval Warm Period

Sun ,01/04/2012

“How can science claim man is the cause of global warming when the temperature of the Earth was much warmer during the Medieval Warm Period (MWP)?”

The science Skeptics are quite adept at casting doubt on climate science by using clever arguments. One of their favorites is “How can science claim man is the cause of global warming when the temperature of the Earth was much warmer in the last millennium during the Medieval Warm Period (MWP)?”  You don’t really have to be a scientist to figure out that there were no accurate temperature records during the Medieval times and that much of the world was unknown.

The Skeptics usually point to historical records such as those by H.H. Lamb, which describe record heat waves in the known world during the MWP. Skeptics rather ignore the fact that H.H. Lamb was so concerned about the effect of global warming that he founded the Climate Research Unit (CRU) to study the Earth’s temperature records. The scientific questions comes down to  (1) whether the MWP was worldwide, (2) how warm the Earth actually was during the MWP, and (3) what caused the MWP?

Since there were no thermometers and no worldwide network of weather stations during the MWP, scientists have used a variety of proxy data from ice cores, isotope ratios, sediments, geological records, and even tree rings to try to reconstruct the temperatures for the last thousand years. Though there are large uncertainties in proxy records and they require careful calibration, they do show a similar pattern as you can see in the figure below, which is made up of 10 different reconstructions. The black line is the instrumental temperature record.* (See end of article for references.)

 

Though there are wide uncertainties in the proxy temperature records, taken together they form an overall pattern which answers the scientific questions. The proxy records show that that (1) there was a warm period from  AD 1000 to 1200, followed by a cooler period from  AD 1550 to1850  NASA identifies as the Little Ice Age, though it was not a true Ice Age. The record also show that (2) temperatures during the  MWP were quantitatively lower than the temperatures during the latter 20th century. To discover the cause of the MWP, it is necessary to look at another reconstruction.

While studying the cause of the past Ice Ages, scientists have identified the three  main factors which affect the Earth’s temperature, solar irradiance, greenhouse gases (primarily H2O and CO2), and particulates from volcanic activity. Below is a reconstruction of the three main factors controlling the Earth’s temperature. There are many interesting things in the records, but they show (3) the Earth was likely warmer worldwide during the MWP because of the higher solar radiation. It also shows that the solar radiation has been relatively constant during the last century while the other factors, primarily greenhouse gases, have increased.

 

 While it is possible to dispute or argue about the meaning of any of the individual records, it is rather disingenuous to claim that scientists “ have no data” or to dispute the obvious causes of the current global warming. To emphasize that, below is data from the last century, which is based on scientific records. While H20 and clouds accounts for about 75% of the greenhouse warming, their effect has increased only slightly( about 4%) while the amount of carbon dioxide has increased by about 39% in the last century.

CO2: Man is now putting about 30 billion tons of carbon dioxide into the air each year. About half of it dissolves in the ocean and they have become 20% more acidic in the last century. Much of the rest stays in the air, and  CO2 is building up in air:

Temperature: CO2 is one of the greenhouse gases that warm the Earth, and NASA’s graph shows how its increase is changing the Earth’s temperature. Note:  The effect of particulates from the explosion of Pinaturbo can be seen in the temperature decline from 1991 to 1995.

 

NASA GISS 2010A

 

The Sun: The current global warming is often wrongly attributed to an increase in intensity of the sun. The sunspot activity does not show up above the noise in the temperature record above. The solar irradiance increased slightly until 1960 and has declined slightly since then.

 

There is the scientific story. Disputes in science are settled by the data. Though Skeptics may dispute the evidence showing the current global warming is caused by man, the question is ” Where is the evidence?”

* References for temperature reconstructions:  The original version of this figure was prepared by Robert A. Rohde from publicly available data from NOAA and the references therein. The article stated: “For the purposes of this comparison, the author is agnostic as to which, if any, of the reconstructions of global mean temperature is an accurate reflection of temperature fluctuations during the last 2000 years. “ The reconstructions used, in order from oldest to most recent publication are:

  • (dark blue 1000-1991): P.D. Jones, K.R. Briffa, T.P. Barnett, and S.F.B. Tett (1998). “High-resolution Palaeoclimatic Records for the last Millennium: Interpretation, Integration and Comparison with General Circulation Model Control-run Temperatures”. The Holocene 8: 455-471. doi:10.1191/095968398667194956
  • (blue 1000-1980): M.E. Mann, R.S. Bradley, and M.K. Hughes (1999). “Northern Hemisphere Temperatures During the Past Millennium: Inferences, Uncertainties, and Limitations”. Geophysical Research Letters 26 (6): 759-762.
  • (light blue 1000-1965): Crowley and Lowery (2000). “Northern Hemisphere Temperature Reconstruction”. Ambio 29: 51-54. Modified as published in Crowley (2000). “Causes of Climate Change Over the Past 1000 Years”. Science 289: 270-277. doi:10.1126/science.289.5477.270
  • (lightest blue 1402-1960): K.R. Briffa, T.J. Osborn, F.H. Schweingruber, I.C. Harris, P.D. Jones, S.G. Shiyatov, S.G. and E.A. Vaganov (2001). “Low-frequency temperature variations from a northern tree-ring density network”. J. Geophys. Res. 106: 2929-2941.
  • (light turquoise 831-1992): J. Esper, E.R. Cook, and F.H. Schweingruber (2002). “Low-Frequency Signals in Long Tree-Ring Chronologies for Reconstructing Past Temperature Variability”. Science 295 (5563): 2250-2253. doi:10.1126/science.1066208.
  • (green 200-1980): M.E. Mann and P.D. Jones (2003). “Global Surface Temperatures over the Past Two Millennia”. Geophysical Research Letters 30 (15): 1820. doi:10.1029/2003GL017814.
  • (yellow 200-1995): P.D. Jones and M.E. Mann (2004). “Climate Over Past Millennia”. Reviews of Geophysics 42: RG2002. doi:10.1029/2003RG000143
  • (orange 1500-1980): S. Huang (2004). “Merging Information from Different Resources for New Insights into Climate Change in the Past and Future”. Geophys. Res Lett. 31: L13205. doi:10.1029/2004GL019781
  • (red 1-1979): A. Moberg, D.M. Sonechkin, K. Holmgren, N.M. Datsenko and W. Karlén (2005). “Highly variable Northern Hemisphere temperatures reconstructed from low- and high-resolution proxy data”. nature 443: 613-617. doi:10.1038/nature03265
  • (dark red 1600-1990): J.H. Oerlemans (2005). “Extracting a Climate Signal from 169 Glacier Records”. Science 308: 675-677. doi:10.1126/science.1107046

(c) 2012 J.C. Moore

Note added on 07/09/2013 : In a new study by the PAGES 2k project, that was  published in Nature Geoscience , 78 researchers from 24 countries worked for seven years on the most extensive climate reconstruction to date of the past 2000 years.  It is based on 511 climate archives from around the world, from sediments, ice cores, tree rings, corals, stalagmites, historical documents and measurements.  Their  graph below confirms the basic “hockey stick” shape of the graph:Pages 2K

 

 

Global Warming in Pictures

Thu ,01/09/2011

Science is about using observation and reason to understand the physical world. Some people are suspicious of computer models and theories; so here is the basic data about global warming in pictures and graphs.

Ice Ages: In the past, the Earth’s temperature has varied from the Ice Ages to the much warmer temperatures of the interglacial periods.  Ice core data gives a good picture of what has happened to the Earth’s temperature in the last half million years, as shown by the blue line. The changing temperatures are attributed to the Milankovitch Cycles, small variations in the Earth’s orbit that cause the Earth to receive different amounts of sunlight. The Earth becomes slowly warmer during the periods where the solar energy increases. As the Earth begins to be warmed by sunlight, CO2 becomes less soluble in the ocean and the CO2 concentration in the atmosphere increases, which further amplifies the warming since CO2 is a greenhouse gas.

As you can see in the graph, the red line shows how intricately the CO2 concentrations and temperatures are related. The CO2 concentration drops to about 180 ppm during the glacial periods and rises to about 290 ppm during the warmer interglacial periods. As the far right of the graph shows, we are now in an interglacial period that began about 6000 years ago. The Milankovitch Cycles predict that Earth should slowly cool for the next 20,000 years, but it is warming instead.  Please note that the concentration of CO2 did not rise above 300 ppm in any previous warmer periods but on the far right side of the graph, the red line indicating the CO2 concentration is now approaching 380 ppm. http://www.daviesand.com/Choices/Precautionary_Planning/New_Data/IceCores1.gif

Current CO2 Levels: In the past, the warming oceans released the CO2 as a natural process. However, man is now putting about 30 billion tons of carbon dioxide into the air each year. Much of it stays there and the Keeling curve below shows how CO2 is building up in air. What might that mean for man? In 2011, the CO2 concentration reached 387 ppm, far higher than it has been for perhaps 15 million  years.

  

 This article explains what the Earth may have been like then: “The last time carbon dioxide levels were apparently as high as they are today — global temperatures were 5 to 10 degrees Fahrenheit higher , the sea level was approximately 75 to 120 feet higher, there was no permanent sea ice cap in the Arctic, and very little ice on Antarctica and Greenland.”

 

Earth’s Temperature: Carbon dioxide is one of the greenhouse gases that warm the Earth. NASA’s graph below shows how its increase is changing the Earth’s temperature. Though the Earth’s mean temperature varies widely from year to year, the graph on the right is a moving average that allows you to see the trend in the temperature much easier.

                                                           htp//data.giss.nasa.gov/gistemp/2010november/fig2.gif

  The effect of particulates, which cool the Earth, can be seen around 1991 when Mount Pinaturbo exploded. The flat place in the graph from about 1940 to 1970 is attributed to particulates generated by World War II, atmospheric atomic bomb testing, and postwar industrialization – before particulate emissions were regulated. Clearly, the Earth is getting warmer.

Record Temperatures: Nine of the 10 hottest years on record occurred in the last decade. The other record-breaking year was 1998. the chart gives the record temperatures for 50 years and the inset for the last last 160 years.

Capture

 


This has led to extreme heat waves  in areas such as Moscow.

 

Moscowjulytempanomaly2010 

 

Effect on the Weather:  According to NOAA, global warming is affecting the El Niño and La Niña ocean currents cycles which affect  the weather patterns in North America.  The cycles are occurring at higher temperatures and are becoming more unpredictable . Changes in ocean currents may be a major tipping point in climate change.

Enso-global-temp-anomalies

Effect on the Earth: Scientist tell us that the increasing CO2 concentration is leading to a warmer Earth, more extreme weather, melting glaciers and polar ice, crop failure, droughts, and wildfires. We have certainly experienced many of those things recently, which should make us think about what effect our activities are having on the Earth. Many of the changes in the Earth are subtle, but here are two of NASA’s pictures that clearly show how the Earth is changing. Between 1979 and 2010, about 30% of the Arctic ice has disappeared.

Current Sea Ice

 This has greatly affected the way of life of the native Inuit who live and hunt on the Polar ice.  While they may adapt, their way of life and culture which sustained them for centuries will be destroyed. The Polar bears, uniquely adapted to live in on the Polar ice, have been put on the threatened species list because their habitat is clearly declining.  As their habitat disappears, so will be the Polar bear. It is something man should think about – as our habitat is deteriorating, also.

 Note: This was posted on 09/01/2011 and updated on 03/06/2013 to include data that was not presented in this more comprehensive collection of pictures and graphs of global warming data.

(c) 2011/ 2013 J.C. Moore

Bits and pieces 10: Global Warming in Pictures

Wed ,31/08/2011

Science is about using observation and reason to understand the physical world. Some people are suspicious of computer models and theories; so here is some of the the basic data in pictures and graphs.

Ice Ages: In the past, the Earth’s temperature has varied from the Ice Ages to the much warmer temperatures of the interglacial periods.  Ice core data gives a good picture of what has happened to the Earth’s temperature in the last half million years, as shown by the blue line. The changing temperatures are attributed to the  Milankovitch cycles,  small variations in the Earth’s orbit that cause the Earth to receive different amounts of sunlight. The Earth becomes slowly warmer during the periods where the solar energy increases. As the Earth begins to be warmed by sunlight, CO2 becomes less soluble in the ocean and the CO2 concentration in the atmosphere increases, which further amplifies the warming since CO2 is a greenhouse gas.  The CO2 did not rise above 300 ppm in any of the the warmer interglacial periods but it is now 398 ppm and rising.

IceAges

 

  CO2: Man is now putting about 30 billion tons of carbon dioxide into the air each year. About half of it dissolves in the ocean, making them 20% more acidic, and the rest increases the concentration in the air.

 

Temperature: CO2 is one of the greenhouse gases that warm the Earth, and NASA’s graph shows how its increase is changing the Earth’s temperature:

 

The Sun: The current global warming is often wrongly attributed to an increase in intensity of the sun. The sunspot activity does not show up above the noise in the temperature record above – and the solar irradiance increased slightly until 1960 and has declined slightly since then.

 

Arctic Ice: Many of the changes in the Earth are subtle but this NASA picture clearly shows  how the Earth is changing:

 

 

Arctic ice:  The next two graphs show quantitatively how both the extent and the volume of the Arctic ice is changing.

 

 

Arctic ice volume at each years minimum.

 

Antarctica: Research by Steig and by O’Donnell  show that Antarctica is warming. The warmer oceans result in more snowfall which increases the inland glacier mass, but the erosion of ice by the warmer oceans is causing an overall loss of ice mass.

 

Antarctic ice mass from GRACE satellite data.

Antarctic ice mass from GRACE satellite data.

 

 

Greenland: The Greenland ice sheets are also beginning to decline.

 

Ocean Level Rise: The melting ice sheets, melting glaciers, and thermal expansion are causing the oceans to rise by about 3 mm per year which, though it seems small, amounts to an increase in ocean volume of 1190 cubic kilometers/yr.

 

Rise in Sea Level.

 

Severe Weather: Warmer temperatures increase both the rate of evaporation and the energy and moisture in the air. This has doubled the incidence of severe weather, floods, droughts, and wildfires.

 

Permission Courtesy of Munich Re.

Permission Courtesy of Munich Re.

 

 

Economic Costs: Large insurance companies such as Suisse Re now consider global warming a risk factor as there has been a fivefold increase in billion-dollar weather events in the last 30 years.

 

 

Droughts: The Palmer Drought Index below includes most of the continental areas used for food production. Zero represents average rainfall and -4 represents extreme drought. Since 1980, drought conditions have grown worse worldwide, and no one disputes the effect of droughts on food production.

 

Food Production: The increasing CO2, temperatures, and droughts are expected to decrease food production worldwide.
Figure-28
Extreme Temperatures: Climate scientists now have enough data and computing power to estimate the probability of extreme weather events. The figure below, from a paper by  Hansen et. al.,shows how the distributuion of temperature have varied over the past 60 years. Extremely hot temperatures, those over 3 standard deviations from the mean,  are now over 20 times as probable as for the 1950 – 1980 period and 10 times as probable as for the 1980 – 2010 average.  That means that extreme temperatures that affected less than 1% of the landmass in 1980, now affect almost 10% of the landmass annually.

Note : This was posted on 08/31/2011 and  updated on 04/03/2012,08/11/2012, and o2/12/2013.

(c) 2011  J.C. Moore

Is Global Warming a Hoax?

Tue ,10/05/2011

Sen. James Inhofe (R –OK) is famous for his statement, “Global warming is a hoax”. The local Tulsa newspaper often carries letters giving the opposing viewpoint. For example, Corey Cohen, recently wrote, “Sen. Inhofe, please cease your effort to stop EPA’s ability to limit greenhouse gas emissions. The science of global warming and climate change is obvious and known. For example, excessive CO2 in the atmosphere absorbs heat reflected from the ground and traps that heat in the atmosphere, melting glaciers and ice and snow packs all around the planet. A given molecule of CO2 in the atmosphere has a life of approximately 100 years. The implications are fairly obvious: rising sea levels, loss of fresh water for humans and unpredictable growing seasons for Oklahoma farmers and their winter wheat crops due to atmospheric heating.” (1)

Mr. Jack Williams replied (2) by “pointing out a few facts”  to defend Senator Inhofe’s position:

“1. More than 31,000 scientists signed a petition opposing the concept of man-made global warming.

2. More than 100 top climate scientists have expressed their opposition.

3. A dozen recognized scientists from nine countries who initially were global-warming proponents have changed their opinion and now oppose it in light of recently published information.

4. Earth has undergone many cooling and warming periods during its history.

5. Carbon dioxide constitutes less than 0.1 percent of the atmosphere while water vapor, at least as effective a greenhouse gas as CO2, ranges from about 20 to 100 times its concentration, and is quite variable.

6. There has been no measurable increase in global temperatures during the past decade.

7. The polar bear population dramatically increased during the past decade, as has ice thickness on Antarctica.”

It’s always nice to get alleged facts in a numbered list, where it is possible to check them one by one.

Endorsements: Facts one, two and three, fall into  the category of endorsements, and as with many endorsement, it is not always clear how well qualified those who endorse the position are, or whether the numbers listed are significant. There are about 23 million graduates with degrees in science and engineering. If 31,000 scientists signed the Oregon Petition, that is about 0.13% of those – hardly significant. Even then, the petition appears to be a hoax. In 1989, the Petition was mailed to thousands of Bachelor of Science students. It was formatted to appear as if it came from the National Academy of Science, but the organization quickly responded that the information was misleading and “the petition does not reflect the conclusions of expert reports of the Academy.”  The mailing collected 17,000 signatures and 14,000 have been added since. Most anyone could sign it, many who signed were misled, and many were not scientists at all, as it is possible to get BS degrees in fields such as journalism, sociology, education, philosophy… (3)

Endorsements that matter: All the major scientific organizations in the world have endorsed a statement such as that of the American Chemical Society,  “Careful and comprehensive scientific assessments have clearly demonstrated that the Earth’s climate system is changing rapidly in response to growing atmospheric burdens of greenhouse gases and absorbing aerosol particles. There is very little room for doubt that observed climate trends are due to human activities. The threats are serious and action is urgently needed to mitigate the risks of climate change.” (4) A recent CNN poll found that 97% of scientists who are actively engaged in research in climate science agree that global warming is caused by man. (5) There is clearly a consensus among scientists on the matter and those making policy would be wise to heed it.

Warming and Cooling: Point four is a fact, but it is not relevant to what is happening today. The Earth has in the past had many natural warming and cooling periods but the current warming trend is not part of those. In the  past, ice ages and warmer interglacial periods have occurred in roughly 100,000-year cycles. These are attributed to the Milankovitch cycles. These cycles are small variations in the eccentricity, axial tilt, and precession of the Earth’s orbit that cause the amount of sunlight the Earth receives to increase and decrease in predictable cycles The cycles predict that a slow cooling trend, which began some 6,000 years ago, will continue for the next 23,000 years. The current warming trend is too rapid and in the wrong direction for the Milankovitch Cycles to be the cause. (6)

Greenhouse gases: Point five is also a fact, but it incorrectly downplays the role of  CO2  in determining the Earth’s temperature. In 1956, G.N. Plass calculated (7) that doubling the concentration of CO2 in the air would cause a 3 to 4 C increase in the Earth’s temperature. Many dismissed his work, as it seemed impossible that CO2, which made up only 0.03% of the air, could have such a large effect on temperature.   However, in 1997, J.T. Kiehl found (8) that, under clear sky conditions, CO2 accounted for 26% of the greenhouse effect – with water vapor accounting for most of the rest. More recent research (9) has confirmed their work, and CO2 has been labeled the “Control Knob” for the Earth’s temperature.  Recent research in the Journal of Climate, covering the last five ice ages, has experimentally confirmed Plass’ work. The Earth is warming because of the greenhouse gases we emit, and research finds the increase in CO2 is the main cause.

Temperature record: Fact six is based on the idea that 1998 was so hot, it couldn’t have been hotter since. However, NASA’s temperature record shows that 2005 and 2010 are tied for the warmest year on record and the last decade has been the hottest in recorded history – and the trend is yet upward (10). There have been attempts to discredit NASA’s temperature data by challenging the accuracy of the temperature recording stations, but a study of that issue by the American Geophysical Union found that claim to be false. (11) NASA has put men on the Moon and brought them home safely, and they certainly should be able to measure temperatures on the Earth correctly.

Polar Bears:  It’s true that the Polar bear population has increased, but not because the Polar ice is increasing. The bears were hunted nearly to extinction, and their population is increasing because restrictions were placed on hunting them from aircraft . Recently, Polar bears have been put on the threatened species list, not because of their numbers, but because their habitat is disappearing.  Satellite measurements of the Arctic sea ice have shown that both the volume and extent of the sea ice has decreased remarkably over the last 30 years. (12) Polar bears are uniquely adapted to live and hunt on the Arctic Sea ice. As it disappears, so will the Polar bears.

Claiming something as “fact” does not make it so. And, even facts can be misleading if the inferences drawn from them are in error.  If Senator Inhofe bases his position on facts such as those listed by Mr. Williams, it is easy to see why he incorrectly thinks global warming is a hoax.

(1)http://www.tulsaworld.com/opinion/article.aspx?subjectid=62&articleid=20110313_222_G2_CUTLIN933913

(2)http://www.tulsaworld.com/opinion/article.aspx?subjectid=62&articleid=20110403_62_G2_InhisM784632

(3) http://jcmooreonline.com/2010/01/29/the-oregon-petition-how-can-31000-scientists-be-wrong/

(4) http://en.wikipedia.org/wiki/Scientific_opinion_on_climate_change#General_science

(5) http://articles.cnn.com/2009-01-19/world/eco.globalwarmingsurvey_1_global-warming-climate-science-human-activity

(6) http://jcmooreonline.com/2010/12/31/science-global-warming-and-the-ice-age-mystery/

(7) http://www.aip.org/history/climate/co2.htm#M_25_

(8) http://journals.ametsoc.org/doi/abs/10.1175/1520-0477%281997%29078%3C0197:EAGMEB%3E2.0.CO;2

(9) http://www.sciencemag.org/content/330/6002/356.abstract

(10) http://data.giss.nasa.gov/gistemp/2010november/fig2.gif

(11)http://www.agu.org/pubs/crossref/2010/2009JD013094.shtml

(12) http://climateprogress.org/wp-content/uploads/2011/01/NSIDC-12-10.gif

(c) 2011 J.C. Moore

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Science, Global Warming, and the Ice Age Mystery

Fri ,31/12/2010

In the early 1800’s, scientists began a search for the cause of the ice ages. That search has led to a discovery of the factors that affect the Earth’s temperature, an understanding of the current global warming, and the solution to the mystery of the ice ages. *

The Data: Science is a way of understanding nature by using observation and reason. Man has always been keenly interested in the weather, but temperature records before 1850 were mostly historical accounts of storms, heat waves, or when bodies of water froze. Thermometers came into use in about 1850, allowing more accurate temperature records. One of the most useful records is NASA’s graph of the Earth’s annual mean temperature, which was compiled from ships logs, weather stations, and satellite measurements. It serves as a scorecard for telling whether the Earth is getting warmer or cooler. NASA’s data has small random variations from year to year because of factors such as sunspots, weather events, ocean currents, and particulates from volcanic eruptions. However, NASA’s graph shows that the Earth’s temperature has clearly trended upward since 1880 – with the exception of a curious plateau from 1945 to 1975 followed by a steeper rise in temperature. The Earth’s mean temperature is now 1.3 F higher than in 1880, and the last decade has been the hottest on record. Any theories or causes put forward to explain the global warming trend must be consistent with the temperature observations.

Possible Causes: Nineteenth century scientists realized from geological evidence that the Earth had gone through many ice ages that alternated with ages of warmer climate. Much of the early research on global warming was a search for the cause of the ice ages. Scientists found that many small variables cause the Earth to warm and cool, but the main three causes are the Sun, particulates, and greenhouse gases.

The Sun’s output seems to have been reasonably stable over the last several million years. Satellite measurements over the last 30 years have shown that while solar radiation has declined ever so slightly during that time, the Earth continued to warm – so clearly changes in the Sun’s output is not the cause of the recent warming. The amount of sunlight the Earth receives does, however, depend on the Milankovitch Cycles. These cycles are small variations in the eccentricity, axial tilt, and precession of the Earth’s orbit that cause the solar insolation, the amount of sunlight the Earth receives, to vary slightly in predictable cycles. Ice core data shows that ice ages tend to occur in roughly 100,000-year cycles that match the timing of the Milankovitch cycles. The temperature between the ice ages and the warm periods, however, are much greater than would be caused by the changes in solar radiation alone. Though a clue to the cause of the ice ages, the Milankovitch Cycles are not the cause of the current warming. They predict a minor cooling trend, which began some 6,000 years ago, will continue for the next 23,000 years. The current warming trend is too rapid and in the wrong direction for the Milankovitch Cycles to be the cause.

Particulates cause the Earth to cool by reflecting incoming sunlight back into space. The role of particulates in cooling the Earth became apparent in 1816 when ash from the explosive eruption of Mt.Tambora caused that year to be called “the year without a summer”, worldwide. The curious plateau in NASA’s temperature record from 1945 to 1975 was primarily caused by particulates from sources such as WW II, atmospheric nuclear testing, and increased industrialization. Research during the early 1970’s showed a huge increase in aerosol particulates from power production, factories, and vehicles – and some alarmists even speculated that we might cause another ice age. Particulates are visible and cause immediate health problems, so by 1980 most industrialized countries had restrictions on particulate emissions. Particulates cannot be the cause of global warming, but reducing their sources can cause the temperature to rise as can be seen in the temperature record after 1980.

The Greenhouse Effect was discovered in the early1800’s when scientists realized that the Earth was kept warm at night because the atmosphere trapped invisible heat rays rising from the surface. Around 1860, John Tyndall identified the invisible rays as infrared radiation and found the main gases that trapped the heat rays to be water vapor and CO2. The amount of water in the air remains relatively constant because of the water cycle. When the humidity is low, water evaporates, and when the humidity gets too high, it rains. However, CO2 has no such restrictions. Since CO2 makes up only a few hundredths of a percent of the air, it was at first dismissed as a possible cause of warming, especially since it was thought that plants and the oceans would absorb any excess.

In 1896, Svante Arrhenius, while still pursuing the idea that variations in CO2 might be the cause of the ice ages, laboriously calculated the effect of cutting the amount of CO2 in the atmosphere by half. He found that doing so would lower the temperature of Europe by 4-5 C, perhaps enough to bring on an ice age. He also found that doubling the amount of CO2 might raise the temperature of the atmosphere by 6-7 C. No one was concerned as Arrhenius’ model of the atmosphere was very crude and it was inconceivable that the amount of CO2 in the air could ever double. Some scientists speculated that man should intentionally add more CO2 to the air to ward off another ice age.

As models of the atmosphere improved, a number of scientists tried to get a better estimate of the effect of doubling the amount of CO2 on the Earth’s temperature, but the increasing complexity of the models made the calculations daunting. A breakthrough came with the development of computers. In 1956, G.N. Plass calculated that doubling the concentration of CO2 in the air would cause a 3 to 4 C increase in the Earth’s temperature. ** Many dismissed his work, as it seemed impossible that CO2, which made up only 0.03% of the air, could have such a large effect on temperature. However, in 1997, J.T. Kiehl found that, under clear sky conditions, CO2 accounted for 26% of the greenhouse effect – with water vapor accounting for most of the rest. More recent research has confirmed their work . Clearly, CO2 could have a significant effect on the Earth’s temperature if it was increasing. But was it?

CO2: In 1900, Arvid Hgbom calculated the amount of CO2 emitted by industrial sources and, surprisingly, found that man was adding CO2 to the atmosphere at roughly the same rate as volcanoes. No one thought much of it as, at that rate, it would take centuries for the amount of CO2 to increase significantly. However, after a protracted heat wave during the 1930’s, Guy Callendar re-examined previous temperature and CO2 measurements and found not only that the Earth was getting warmer, but also that atmospheric CO2 concentrations were increasing rapidly. Callendar’s work was mostly ignored, but a few scientists began monitoring the concentration of CO2 more closely. Their results were sporadic but, by 1958, Charles Keeling had established accurate procedures for measuring atmospheric CO2. His lab was eventually moved to the Mauna Loa observatory, far away from most CO2 sources. His graph showing how CO2 varies with time, now called the Keeling curve, proved to be an important piece of evidence. It showed that the oceans and plants were not taking up CO2 nearly as fast as man was producing it. Over the last century, the atmospheric CO2 concentration has risen from 280 parts per million (ppm) to 385 ppm, a 38% increase, and the Earth’s temperature has risen by 0.8 0C, well in line with Plass’ prediction. The role of CO2 as the major cause of global warming had been convincingly established. There is yet one more piece of evidence that confirms that conclusion.

Ice Ages: It was now possible to solve the mystery of the ice ages. The Milankovitch cycles alone cannot explain the changes in the Earth’s temperature during the cycles, but the process becomes clear if CO2 is included. The ice core data shows that the concentration of CO2 falls to about 180 ppm during an ice age and rises to about 280 ppm during the warm part of the cycle. The changing CO2 concentration happens because the solubility of CO2 in water varies with temperature. In the part of the cycle where the Earth is warmed by the increasing solar radiation, the oceans release CO2, which further amplifies the warming by the greenhouse effect. In the part of the cycle where the solar energy decreases, the oceans cool, the CO2 dissolves again, and another ice age begins. The concentration of CO2 in the atmosphere is the “control knob” for the Earth’s temperature – and we have now turned the knob up to 380 ppm and are moving it even higher. The Earth will surely get warmer.

* Much of the historical data came from this excellent AIP article.

 **  Recent research in the Journal of Climate, covering the last five ice ages, has experimentally confirmed Plass’ estimate of the climate sensitivity.

(C) 2010 J.C. Moore