Carbon dioxide and other greenhouse gases (GHGs) are responsible for global warming, the long-term worldwide average warming experienced since the industrial revolution. GHGs arise from human use of fossil fuels for energy. Major emitters of GHGs include both industrialized countries and, in recent decades, developing countries as well. Higher global temperatures cause the extremes of hot and cold, and wet and dry, weather of recent years. This blog examines global warming and its effects.
See the Tabbed Pages for links to video tutorials, and a linked list of post titles grouped by topic.
This blog is expressly directed to readers who do not have strong training or backgrounds in science, with the intent of helping them grasp the underpinnings of this important issue. I'm going to present an ongoing series of posts that will develop various aspects of the science of global warming, its causes and possible methods for minimizing its advance and overcoming at least partially its detrimental effects.
Each post will begin with a capsule summary. It will then proceed with captioned sections to amplify and justify the statements and conclusions of the summary. I'll present images and tables where helpful to develop a point, since "a picture is worth a thousand words".
Thursday, September 29, 2011
Rejecting the Science We Don’t Like
Summary.The scientific method dictates that research be carried out in an open, unbiased way.Desired results may not be determined ahead of time.Peer review by anonymous reviewers ensures that published reports are objectively presented and that their conclusions are supported by the data.
This post presents six examples of important scientific and technological advances that have improved human life over the past 150 years, and two examples in which useful technologies carried with them unintended, harmful side effects.Scientific research helped identify the causes of the harms, and provided ways to overcome them.
Recognition of global warming did not occur by predetermining this result and seeking data to support the concept.Rather it was characterized by open scientific inquiry conducted by myriad scientists around the globe for the last several decades.Global warming and its harms to human life and to the ecology of the earth are unintended consequences of our use of fossil fuels.Those who disparage the notion of man-made global warming must be consistent in their acceptance or rejection of the results of scientific inquiry.They cannot pick and choose which science to accept and which to reject.Consistency would require them not to accept the benefits that modern science and technology confers on them.
Introduction – the process of scientific inquiry.All scientists carry out their research according to well-established principles of scientific investigation. Science is undertaken as an objective, unbiased inquiry.Scientists engage in their investigations with an open mind, avoiding any prior direction of what the result of the investigation should reveal.Valid science is not conducted by adopting a conclusion at the outset and seeking out those particular findings that bear out the preordained conclusion stated at the outset, or by casting the framework of a study in such a way as to provide those results.
In order to publish their results, scientists submit their manuscripts for scrutiny by their peers.In this process, the editor of a journal, upon receiving a manuscript, sends it to two or three scientists who are expert in the field for critical evaluation.Importantly, these reviewers remain anonymous to the authors of the manuscript.A reviewer may accept the work as is, reject it outright, or require responses to certain criticisms he/she may develop prior to acceptance.
Peer review ensures that no biased or unsubstantiated points of view, or inaccurate scientific conclusions, are published.In addition, in contemporary scientific practice, the publishers of most journals require authors expressly to identify any interests they have that may be construed as being in conflict.
This post discusses selected examples of beneficial scientific and technological breakthroughs, as well as some cases in which technology produced harmful unexpected consequences.The role of science in these examples is emphasized.
Telegraph and telephone. The invention of the telegraph represents the very first time that humans had the ability to transmit information faster than they could personally move it.The electrical telegraph signals were transmitted along wires essentially instantaneously.
The invention of the telephone was equally as revolutionary, as it enabled the human voice for the first time to be transmitted instantaneously across vast distances.
Each of these developments was strongly based on existing scientific and technical knowledge.Samuel Morse developed the telegraph in 1837.It built on the understanding and development of electricity, especially the use of electrical wires wound around an iron core to generate a magnetic field.Alexander Graham Bell received a U. S. Patent for the first telephone in 1876.Here too, knowledge of electromagnetism was applied in building the ear speaker and a separate, more complex assembly used for the microphone, such that sound waves are converted into an electric current whose variations accurately represent the original voice.Clearly humanity has benefited tremendously from these examples of applied science and technology, vastly expanding our ability to communicate.
Vacuum tubes, transistors and radio/television.The early electronics industry (early 20th century) relied not simply on electricity, but on discovering that the passage of electrons emitted from, say, a hot filament placed in a high vacuum, can be controlled by additional electrical elements placed along the path of the electrons.The flow of electrons ultimately reaches a receiving wire, all within the vacuum tube.In this way electrical current can be instantaneously modulated by the control element(s).Many electronic devices using vacuum tubes were developed, but perhaps the most significant was the radio.Radio communication, and later television transmission, took the instantaneous transmission of information of the telegraph and telephone one step further, relieving it from its reliance on wires for transmission from the source to the destination.Development of vacuum tubes required groundbreaking research into electron physics.In addition radio and television capitalized on theoretical and experimental physics developed during the last half of the nineteenth century.
Transistors were developed after World War II.These are solid state devices based on the properties of semiconductors that perform similar functions as a vacuum tube – the controlled passage of electric current.Since transistors are easily produced in quantity, are easily incorporated into larger circuits known as integrated circuits, and require much less power to operate than vacuum tubes, they have completely replaced vacuum tubes in electronic appliances and instruments produced today.Development of transistors relied strongly on basic research in solid state physics and the properties of materials.
The pharmacological benefits of aspirin were first recognized in the late 19th century.Chemists in the German company Bayer AG were the first to synthesize and name the compound we know as aspirin.But the question of understanding how aspirin works at the molecular, or physiological, level remained unanswered for about seven decades.
During the 1960’s and 1970’s, as a result of expanding research in biochemistry and molecular pharmacology, the cellular enzymatic pathways leading to formation of the group of thromboxanes and prostaglandins were clarified.Various members of this group of biochemical compounds were shown either to promote or to suppress inflammatory processes in cells and tissues.It was found that aspirin interferes with an important enzymatic reaction leading to pro-inflammatory responses.For this work, the British pharmacologist John Robert Vane was awarded the Nobel Prize in 1982.Other drugs in this class, the non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and naproxen, also interfere with this biosynthetic pathway. We, as welcoming consumers of NSAIDs, should recognize the important role that basic research plays in this and other important scientific advances.
Antibiotics are drugs that interfere with the growth of bacteria and other microorganisms.We humans benefit from antibiotics because they kill disease-causing bacteria when we become infected with them.This cures an infected patient, thus prolonging her life and wellbeing.Before the advent of antibiotics, humans survived or succumbed to bacterially-caused infections according to the severity of the infection and the strength of the patient’s immune response.
Originally, antibiotics were compounds secreted from growing microorganisms as a defense mechanism against a different microorganism that might attack the secreting species. Penicillin was the first antibiotic to be discovered, by Alexander Fleming in 1928, but it remained for others, Ernst Chain and Howard Florey, to isolate the active compound and determine its chemical structure.They were awarded the Nobel Prize for this achievement in 1945.Humans have benefited vastly by the use of NSAIDs and antibiotics, among many classes of drugs, that have been developed in recent decades through scientific research.
Biotechnology.In recent decades the biotechnology industry has developed and commercialized several new drugs to treat diseases in new ways.This work has relied critically on the results of basic research in biochemistry and molecular biology.Examples of fundamental discoveries laying the groundwork for further developments in biochemistry, molecular biology and biotechnology include restriction enzymes used in genetic engineering (Nobel Prize to Daniel Nathans, Werner Arber, and Hamilton O. Smith in 1978), the polymerase chain reaction (PCR; extremely useful in isolating genes and gene fragments; Nobel Prize to Kary Mullis and Michael Smith in 1993), and monoclonal antibodies, unique antibody molecules that target an antigen of interest (Nobel Prize to Georges Köhler, César Milstein, and Niels Kaj Jerne in 1984).
These advances, and others, have been critical in developing new biotechnology drugs approved for use against certain human diseases.These include recombinant human growth hormone for treatment of pituitary dwarfism; Herceptin ® (trastuzumab), a monoclonal antibody used to treat breast cancer cases in which the protein HER2 (the antibody target) is abnormally high; and Procrit ® or Epogen ®, recombinant forms of the human growth factor erythropoietin that stimulates synthesis of red blood cells, used to counteract anemia, for example in cancer patients.Clearly the long trajectory of scientific research has led to important new treatments benefiting large numbers of patients in the last one to two decades.
Other technological improvements in our lives have led to unintended harmful consequences to the environment.Two examples are provided here.In each case technology produced a harmful result as a side effect.Basic scientific research characterized the problem and identified its cause.This new information led to implementation of suitable policies to overcome the harms.
Acid rain.Pure rain water has an acidity level is that is neutral, having a value on the pH scale of acidity or alkalinity of 7.Solutions of strong acids in water, such as sulfuric acid, can have pH values of say, 2, 1 or 0, with the lower numbers designating stronger acidity.Biological organisms including fish and higher plants grow readily when exposed to water whose pH is near 7.If the acidity gets stronger (lower pH) fish eggs fail to hatch and adult fish are killed.Also, vegetation on land cannot survive and dies as well.
In the northeastern U. S. dying wilderness lakes and forests were noticed beginning around the 1970’s.Research sanctioned by an act of the U. S. Congress established that acidity in lakes due to excess sulfates was characterized.This most likely arises from sulfur impurities in coal burned to generate electricity in the American Midwest, upwind from the damaged areas, which produces the chemical predecessors of sulfurous and sulfuric acids (sulfur oxides).These then drift eastward in the air and fall to earth as both dry particulates and dissolved in raindrops which are made acidic by the sulfur oxides.A forest killed by acid rain is shown below.
In response the Congress amended the Clean Air Act in 1990, setting up a cap and trade market for progressively reducing emissions of sulfur on site at coal-burning plants.Technology for achieving this required power plants to install sulfur oxide scrubbers in the waste gas stream from the plants.They could also switch to low-sulfur coal from the American West. Since these solutions involved new and unanticipated capital investment or other expenses, electric power companies opposed this law, unsuccessfully. By 2007 acid rain levels had fallen by 65%, at a cost estimated at US$1-2 billion.International treaties governing cross-border flow of acidic waste products have also been implemented.
Ozone depletion (see Wikipedia; accessed Sept. 28, 2011).Ozone is a molecule made of 3 oxygen atoms.It forms in the stratosphere (10-50 km; 6-31 mi above the earth) by the action of sunlight on molecular dioxygen (dioxygen (popularly called simply “oxygen”); 2 oxygen atoms).Ozone is important for life on earth because, contrary to dioxygen, ozone absorbs the ultraviolet wavelengths of sunlight that can promote skin cancer and ocular cataracts.
Chlorofluorocarbons (CFCs) are entirely manmade compounds that did not exist prior to modern industrial chemistry.They have been used as the coolant in refrigerators and air conditioners, in aerosol spray cans, and in industrial cleaning and dusting processes.When released into earth’s atmosphere, they can make their way as high as the stratosphere.
Depletion of ozone from the stratosphere has been observed using weather balloons and satellite observations starting in the 1980’s, especially in the spring of the southern hemisphere over Antarctica.The largest Antarctic hole observed, from Sept. 21-30, 2006, is shown in the graphic below.
Antarctic ozone hole from September 21-30, 2006 covering10.6 million square miles (27.5 million square kilometers).The blue and purple colors show areas with the least ozone, and the greens,yellows, and reds are where there is more ozone.
Atmospheric scientists were able to model the destruction of ozone in the stratosphere using specialized instruments and reproduce the process in laboratory experiments on earth.They showed that ozone depletion is catalyzed by CFCs that wind up in the stratosphere. (In catalysis, a molecule participates in promoting a chemical reaction such as the transformation of ozone to dioxygen, but is itself regenerated and can be recycled to participate in many such transformations, not just one.For this reason a small amount of a CFC can contribute to significant extents of ozone depletion.)In this way basic scientific research conducted by academic and government scientists contributed directly to understanding the basis for ozone depletion.For successfully working out the details of the role of chlorofluorocarbons in ozone depletion, Paul Crutzen, Mario Molina, and Frank Rowland were awarded the Nobel Prize in 1995.As the evidence of involvement of CFCs was accumulating, the manufacturers of these compounds and of aerosol spray cans were vilifying the theory (Wikipedia), without offering any scientific evidence to support their position.
In the face of this new understanding that CFCs were responsible for a major part of ozone depletion, nations producing these compounds agreed, in the Montreal Protocol of 1987 as strengthened in subsequent years, to phase these compounds out essentially completely by 1996.Recovery of stratospheric ozone concentrations to original levels will take many decades.
The examples presented here are but a minimal selection of the ways in which science, encompassing both basic research and applied research, and technology, including developing ways to implement basic scientific knowledge in practical ways, benefit humans as we live in the 21st century.Scientific research and development of technology cannot be pre-ordained by the preferences and desires of the researchers and entrepreneurs creating the products.Rather, the facts resulting from these research projects are the only determinants of the paths of progress. When unanticipated harms to the environment arose from using products, as in the cases of acid rain and ozone depletion, unbiased scientific research was critical in establishing the basis of the phenomena, and in suggesting ways to overcome the damages.
The same processes of scientific inquiry that led to the results summarized in the preceding sections have been applied for the past several decades to characterize the warming of the globe.Climate science has ascribed the cause of warming to man-made emissions of greenhouse gases such as carbon dioxide that arise from burning fossil fuels.This outcome was not obtained by predetermining the result and seeking data to support it, but rather as the result of thousands of independent, open inquiries conducted by scientists all around the globe. Clearly, global warming is an unanticipated harmful consequence of our use of fossil fuels as our energy source.
The Intergovernmental Panel on Climate Change (IPCC) issued its Fourth Assessment Report in 2007.The draft of its Synthesis Report (IPCC, 2007: Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, Pachauri, R.K. and Reisinger, A. (eds.)]. IPCC, Geneva, Switzerland; accessed Sept. 28, 2011), was sent for formal review to over 2,400 individual experts as well as to the 193 member governments of the IPCC, attesting to its validity and acceptance by the broad climate science community.
The Synthesis Report states “Eleven of the last twelve years (1995-2006) rank among the twelve warmest years in the instrumental record of global surface temperature (since 1850)…. It is very likely that over the past 50 years cold days, cold nights and frosts have become less frequent over most land areas, and hot days and hot nights have become more frequent.” (emphasis in original). The Report finds that observed rises in sea level and decreases in snow and ice extent are consistent with this warming trend.
There are those who dismiss, disparage or deny the scientific validity of man-made global warming and its consequences.Nevertheless, these same individuals continue to live their lives in the present 21st century, enjoying all the benefits from science and technology that make our lives convenient, pleasurable and healthy.In order to be consistent, however, one cannot enjoy the advantages of our present lifestyle, on the one hand, yet on the other hand selectively choose to disregard the overwhelming scientific evidence supporting the phenomenon of global warming.If those who choose to denigrate global warming are to be consistent with their views on the results of scientific inquiry, they should likewise renege on their lifestyle and give up the comforts and benefits that contemporary life brings them.Their integrity should lead them to accept nothing less.