Q: How did the concept of global warming originate?
A: Global warming is largely derived from the science surrounding the Greenhouse Effect. The Greenhouse Effect operates in the following manner. When sunlight enters the Earth’s atmosphere it eventually strikes some portion of the Earth’s surface. When making contact with the Earth’s surface it is either absorbed or reflected back into space. Note that the term ‘reflected’ is not technically correct, but is an effective way of separating the different scales of what happens to the energy from sunlight when making contact with the surface.
The reflected energy attempts to return to outer space through the Earth’s atmosphere in the form of infrared radiation, but can be deterred by molecular obstacles, most notably greenhouse gases. If these molecules absorb the returning radiation it excites the molecules causing them to collide with other molecules and release that energy. Unfortunately that energy release is not one-directional (i.e. surface to atmosphere), but in all direction including back down to the surface. This redirection of reflected surface radiation results in a greater level of energy retention and thus a warmer temperature. The higher the greenhouse gas concentration in the atmosphere, the higher the probability that reflected energy is returned to the surface and the higher the resultant temperature increase in the atmosphere. Note that the above explanation is just a quick overview of the Greenhouse Effect the overall physics involved are much more specific and complicated.
Overall the issue surrounding global warming is not in the science itself; to reject the Greenhouse Effect is akin to suggesting that 2 + 2 = 1,000,000, but instead the issue is in the question of whether or not human action, largely involving the combustion of fossil fuels, is the principle reason behind the acute temperature increases in recent decades. Those who believe human action is the driving force behind the current warming trend typically refer to the warming as anthropogenic global warming (AGW).
Q: So what are the known greenhouse gases?
A: In order of their perceived influence –
Water Vapor (H2O);
Carbon Dioxide (CO2);
Nitrous oxide (N2O);
Black carbon (black soot);
Hydrofluorocarbons (HCF)/Chlorofluorocarbons (CFC);
Q: How can humans be significantly influencing the climate patterns of the Earth when there are so many factors involved and the carbon cycle operates on a much larger scale than the CO2 emitted by humans?
A: There are two important factors to consider when addressing this question. First, although the natural carbon cycle is considerably larger than what human activity emits, the issue is that the carbon cycle is not adding a significant new CO2 concentration to the environment. Over 99% of the new CO2 that is being added to the environment is derived from human activity. Although this addition is small relative to the total amount in the carbon cycle the climate is delicate enough that the addition of CO2 without the appropriate counter-balance (the ability to remove CO2 from the environment) a rapid change in climate can easily result.
Think of it this way imagine a snowball narrowly balancing on the top of a cliff with steep hills on both sides. There are opposing, but equal forces pushing on the snowball. Because the forces are equal the snowball does not move; however, add a force to one side, even if it is a small force relative to the pre-existing forces, and the snowball will begin tumbling down one side of the cliff because the drop-off point is so close to the original starting point of the snowball.
Second, the speed at which CO2 is being added to the atmosphere is much faster than more natural changes that have occurred in the past. Some like to make the statement that some number of years ago CO2 concentrations were much higher than they are now, which is true; however, it took a lot longer to move from one concentration point to another during that time period relative to the speed of the current concentration change now. That time delay gave the environment an opportunity to slowly adapt reducing potential damage.
Overall although the carbon cycle may be much larger, it is a dynamic, but generally stable cycle that operates over a much slower time frame than the CO2 that is being emitted into the atmosphere by human activities. The issue is not size, but speed and change, both of which are being primarily driven by the actions of humans and not through natural processes.
Q: What are the consequences of global warming?
A: Overall the immediate specifics of any consequences are difficult to accurately specify due to the complex nature of the climate. Basically it is difficult to accurately state with an real level of confidence that due to global warming region x will receive 45% less rain versus the average year a decade ago. However, general statements regarding predictive climate patterns can be made. For example one of the most important consequences is an increase in average global sea levels due to an increased rate and amount of melting of glaciers and sea ice. Such a sea level increase will threaten many coastal cities throughout the world and also pose a legitimate threat to bury a number of island nations underwater.
Also an increase in ocean acidity will be a significant problem leading to a reduction in the biodiversity of the ocean. This reduction in oceanic biodiversity will impact multiple food chains including the amount of fish and other sea life that humans will be able to catch, sell and consume. Overall increasing ocean acidity represents the greatest short-term threat to mass species extinction brought on as a direct cause of global warming.
Third, the increase in average global temperatures and change in precipitation patterns (largely rain) will increase the total stress on drinkable water supplies. Current precipitation patterns seem to be shifting in an extreme manner. Basically wet regions (regions that receive lots of rain) will receive even more rain and dry regions will receive even less rain. Unfortunately such a result is not favorable for either side because more rain will increase the chance of events like flash floods and mud slides and less rain will length droughts and possible famines.
There are other significant consequences such as permafrost melting, possible ocean out-gassing, new cloud synthesis or disappearance at different altitudes, latitude shift in certain animal populations and migratory patterns and many more, but the purpose of this discussion is not to list all of the potential detrimental consequences.
Also on a side note although some claim that there will be benefits to global warming such as more rapid and robust plant growth due to higher levels of CO2 in the atmosphere, which is true, any benefits derived from global warming will be buried under all of the negative consequences making the benefits moot. Also those benefits only function under a certain temperature window, once global temperatures exceed that window then they become detriments instead of benefits.
Q: Why are individuals who do not believe in AGW labeled as ‘deniers’ or worse by the environmental community? Isn’t such action unproductive and pretentious?
A: In the scope of a debate it rarely is a good idea to apply a negative label to your opponent from a logical standpoint. However, the term ‘denier’ has its origins in simple frustration by those that believe global warming has a principle human driver over a natural or unknown driver. These individuals believe that there is more than enough evidence to prove AGW beyond a reasonable doubt and that those who do not acknowledge this reality are ‘denying’ reality. Although the use of such a label is unfortunately, the important thing to acknowledge is that the individuals being labeled as ‘deniers’ have done little to disprove such a label.
In science it is very difficult to prove something beyond any doubt (100% guarantee) because humans typically lack all available knowledge about a given subject and have observational and measurement tools with inherent error. Therefore, scientists work hard to identify the most probable solution to correspond with the information available. Similar to the legal system, science looks to devise theories that explain concepts and observations beyond a ‘reasonable’ doubt, not beyond any doubt. One can be skeptical if it is believed that certain assumptions or calculations that comprise a theory are both in error and sufficiently important enough to the theory. However, if one of these conditions is not met, then it is inappropriate to reject the hypothesized solution unless one can devise a theory that better explains the available data.
The group labeled as ‘deniers’ has yet to find peer-reviewed empirical evidence that is not significantly flawed to support the contention that there is another cause beyond human activities, which explains the increasing temperatures over the last 3 decades. Also the errors that have been suggested in empirical evidence that support AGW have not been identified as critically important to the AGW theory itself. Therefore, nothing exists to counter the claims made by those that support AGW outside of small unimportant portions of the overwhelming evidence that support AGW.
Another reason for such labeling is that in modern society the best way to get attention for a particular message, be it positive or negative attention, is to create sound bite worthy labels. The label ‘individuals that do not believe in anthropogenic global warming’ does not have the same emotional bite as ‘denier’. Others also use these tactics such as the label ‘spend thrift liberal’ instead of ‘individual that is thought to believe in the power of government over the marketplace and expends inordinate amounts of money on government programs to promote economic and social growth’.
Unfortunately the world has drifted more towards emotional arguments than logical arguments, thus labels are used more often to categorize certain viewpoints. Overall although inherently unnecessary, the use of the label ‘denier’ should have no influence on whether or not an individual accepts AGW. For example does it make sense for Person A to reject the premise offered by Person B of 2 + 2 = 4 solely because Person B called Person A an idiot in a prior interaction? Of course not.
Q: What about those flaws in the IPCC report or those climate emails that the media talked so much about? Don’t they disprove AGW?
A: No. As mentioned above neither of those incidents nor anything else that opponents of AGW cite weakens the overall empirical evidence that support AGW. The climate emails can be viewed as damaging before realizing that they are taken out of context and that they do not change the published information available on AGW. The emails simply demonstrate researcher frustration and semantics. Any accusations of collusion between climate scientists are irrational due to the lack of money that would be generated from such collusion. Despite what some opponents say, climate science is not a lucrative profession regardless of whether or not global warming was perceived as a legitimate threat. Also climate scientists do not get into climate science for monetary gain.
The IPCC flaws have nothing to do with whether or not AGW exists, but instead focus on the extent and rate of damage that can be expected in the future due to progressing climate change and global warming. Again the best argument opponents of AGW can make regarding the IPCC flaws is that prediction of certain events in the future was incorrect, but the general nature of the core damage that will occur is not affected by these errors. Also it must be understood that a vast majority of the information contained in the reports produced by the IPCC is mutually exclusive. That is one predictive error does not statistically influence another prediction. Thus even if a predictive error is made, it does not invalidate other predictions, so a small number of errors cannot invalidate separate conclusions derived from the report. Basically if one would think of the IPCC report as a sweater and the current errors as a loose string, pulling on the string does not unravel the sweater, but instead just removes a loose string.
Overall empirical evidence clearly demonstrates a warming climate, both through glacial ice and permafrost melting at a much faster rate than normal and increasing surface air and ocean temperatures derived from satellite measurements, regardless of what any emails say or any errors in the most recent IPCC report.
Q: If global warming means the Earth is getting warmer how come during the winter snow is falling in places that have not gotten or gotten very little snow in the past?
A: The main reason for the occurrence of such events is that although average global temperatures are increasing, the influence of global warming is not isolated to temperature. Due to the breach in balance that has characterized the climate for thousands of years the probability of occurrence of certain weather events has changed. Basically in a climate system influenced by global warming certain weather has a higher or lower probability of occurrence at certain places due to changes derived from a response to the higher temperatures. For example due to global warming it may rain more in one region of a country, but rain less in another region versus historical data. In short global warming increases the probability for and intensity of more extreme weather events, be it floods or droughts, thus it is more probable for the State of Georgia to have a winter blizzard versus three decades ago.
Q: There is so much information out there, especially among blogs. How do I know if someone is lying to me, is just stating an opinion or actually knows the stuff?
A. The simplest way is to look for any citations or mentions of any papers. If none exist and statements do not seem to make sense or come to exotic conclusions then such statements can be dismissed. If citations were made then it would be prudent to check the information (abstracts of each of the papers, etc.) to ensure that the author is interpreting the general results correctly. Another option is to email one of the authors of a cited paper with the link of the blog post and simply ask if the blogger is interpreting the information properly.
Q: If all of the empirical evidence suggests AGW as the principle cause for climate change why do people still reject AGW?
A: Good question. There are three principle reasons why with the current available empirical evidence one would still be skeptical of AGW. First, an individual does not have the experience to effectively analyze the available evidence and come to a firm conclusion regarding the validity of AGW. Unfortunately without this experience these individuals tend to turn to others to fill in the blanks and most of those individuals do so improperly either due to a lack of understanding themselves or purposeful deceit due to personal motives. The problem with this situation is that most of the people who fill in the blanks are television, radio or other media personalities and not climate scientists because these media personalities have a greater opportunity to present their opinion. Clearly the probability that these media personalities misunderstand/manipulate the available information is higher than a climate scientist and is demonstrated on almost a daily basis.
Second, some individuals do not believe that it is in their and/or their country’s best interest for the public to acknowledge AGW, regardless of whether or not they do so in private. These individuals believe that a government issued price on carbon, elimination of fossil fuel subsidies and other strategies to reduce greenhouse gas emissions hurt their own interests. For these individuals the total amount of evidence supporting AGW is meaningless. These individuals work to support a political and scientific environment of, at best confusion, and at worst outright dishonesty to reduce the probability that governments act to stem the threat of AGW.
Third, some people realize that they should change their viewpoint and acknowledge the threat of AGW, but unfortunately these individuals have not separated their personal judgments and beliefs from each other. Basically these individuals believe that if questioning their initial opinion of denying the validity of AGW leads to a change in that opinion, then they will have to challenge every single one of their beliefs and such a scenario scares them. Therefore, they avoid that scenario by never changing any of their initial beliefs, including those surrounding the validity of AGW, regardless of what type of new information may be available since coming to their original conclusion.
Those individuals falling into categories 1 and 3 can still change their minds as long as the elements influencing their decision outside of the evidence are properly addressed within the confines of the argument for AGW. Unfortunately those within category 2 have already decided upon which side of the line to stand regardless of what the evidence reports.
Q: OK suppose global warming is being caused by humans; what can I do, I’m just one person?
A: True, you are just one person and regardless of what some in the environmental movement would like to believe, you really cannot make a difference by yourself. However, just because you cannot solve the problem by yourself, does not mean that you should not make practical and intelligent decisions to help the environment. There are some very easy things that you can do to not only reduce the amount of greenhouse gases you emit into the atmosphere, but also save a significant amount of money.
Most notably if you own your own home or are planning on living in your current home for at least another five years, investments in energy efficiency are definitely worthwhile. For example getting a professional to evaluate points of heat loss in your home will provide the appropriate information relating to what efficiency improvements will be most effective and save you the most money in the long-term. Typically most homes are under-insulated and adding loft and/or wall cavity insulation will significantly reduce heat loss saving energy and money. Also windows with double-glazing will reduce heat loss and can be relatively inexpensive. Any appliances older than six years can be replaced with Energy Star certified appliances, especially dishwashers, refrigerators and washers/dryers. Finally even if the prospect of going through the process of adding solar panels to the roof may not be your liking, the addition of a solar power hot water heater can still be practical, relatively inexpensive and useful.
With regards to transportation, the old motto of ‘don’t drive when you can walk or ride’ should be followed whenever possible. Unless your motor vehicle is over a decade old, replacing it with a new more fuel efficient model may not be prudent for another year or two when the fate and popularity of 100% electric vehicles is better understood. Finally although said many a time it should be repeated, when you have to drive see if you and others in your family or friends can effectively combine tasks and only take one vehicle instead of multiples.
The following blog post identifies some useful websites that will provide more detailed information:
Q: I will definitely look into those things, but if government action is required, what should the government do?
A: Encouraging certain government action is easy in a general sense and difficult in a specific sense. For example one of the most important things to reduce carbon emissions is to place an additional price on carbon. However, the complicated part of issue is what is the best way to accomplish such a price. Methods for attaching this carbon price have culminated into support for either a carbon tax or a cap-and-trade system. Both have strengths and weaknesses, although not surprisingly supporters tend to avoid the weaknesses of their preferred method. Although such a topic demands more in-depth analysis than will be provided in this answer, in short a carbon tax is theoretically more economically efficient and expedient in its execution, but unlike the cap-and-trade system does not generate guaranteed cuts in emissions.
Diversifying alternative/trace emission energy choices is another important government action. At the moment most of the construction of trace emission energy is focused on wind power. Unfortunately there could be significant problems with wind power down the line due to dropping wind speeds ironically as a result of global warming as well as the simple fact that wind power will never provide enough energy by itself. Thus, the government also must encourage investment in solar power (which is progressing very nicely in theory and planning, but going almost nowhere so far in reality), geothermal power (a new geological survey would be beneficial) and biomass to ensure a balanced power grid that does not rely on burning significant amount of fossil fuels.
Nuclear power is a sticky wicket in that it has polarized supporters and opponents a lot like AGW. Both sides seem to agree that when talking rationally meeting future energy requirements without new nuclear power plants will be difficult, but is the cost of their construction worth it? Currently most price estimates for new nuclear power plants paint a picture of unnecessary expense for the benefit derived from their construction. However, those price estimates only involve 2nd generation nuclear plants. Overall it is rational to anticipate that 3rd and 4th generation nuclear power plants would provide much lower cost reality over the long run; however, whether or not research and development will establish a viable long-term nuclear plant beyond 2nd generation remains to be seen.
Another important action is to generate a more streamlined and efficient procedure to approve or deny (on legitimate grounds) new power line construction plans. Most of the trace-emission energy sources like wind, solar, geothermal, etc. have their origins away from dense populations, largely because they require lots of land for construction. Therefore, new transmission lines will be required to ensure that electricity travels efficiently from source to consumer. Unfortunately transmission line construction is a tricky business when constructing between states. Thus an updated system that hastens approval or denial will be effective to ensure more rapid construction and problem identification reducing waste and expense.
Finally the government needs to pass a general federal standard for building efficiency (basically establish a national building energy code). The amount of energy lost through powering buildings just due to their inherent inefficiencies is remarkable. Mixed cost structures and a wide variety of state building codes have lead to a hodgepodge of building requirements creating inefficiency and waste. Creating a standard for current and new buildings would prove to be an important step in increasing overall energy efficiency as a nation and reducing the amount of electricity that needs to be generated from trace emission sources when replacing fossil fuel based sources.
Of course there is still more that the government can do, but most of the important stuff has been mentioned in the above paragraphs.
Q: Thank you for the breakdown regarding global warming, why action has yet to be taken and what actions would be useful. If I want to learn more about the science behind global warming where would I go?
A: It is true that this Q and A was light on the citations largely because there are many sites available that do a high-quality job summarizing the scientific specifics behind global warming and reprinting large swathes of that information here was unnecessary. Also how enjoyable of a conversation would it have been if you were inundated with citations all over the place? It is reassuring that you are interested in expanding your understanding. Good places to start would be:
Union of Concerned Scientists Website:
Union of Concerned Scientists FAQ regarding Global Warming:
NASA GISS Surface Temperature Analysis:
The Copenhagen Diagnosis (PDF):
The National Oceanic & Atmospheric Administration:
Intergovernmental Panel on Climate Change (IPCC) Website:
Also there are a number of posts on this blog that could be helpful to better understanding global warming, its consequences and what to do about it.