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Global Warming Discussion

What to do?

The global warming issue has been labeled the "Science of Uncertainty"

  1. Although we are able to measure a significant rise in the global average temperature in recent years, we are unable to determine how much of the warming is due to the increases in greenhouse gases and how much is part of some natural cycle;
  2. We are unable to predict exactly how climate will change in the future with higher levels of greenhouse gases (or lower levels of greenhouse gases if emissions are eliminated);
  3. We do not entirely understand the impacts that climate changes will have on humans and other life on the planet.
This uncertainty makes it difficult for all people to come together and agree on what, if anything, should be done. Scientists are working on reducing the uncertainties, but due to the complex nature of the climate system, we should not expect certain answers to all questions. We have to make decisions which weigh uncertain risks against the costs of taking action. See Global Warming Facts and Uncertainties

If nothing else, the human race is in the process of performing a huge experiment on global climate by increasing greenhouse gas concentrations. The concentration of carbon dioxide in the atmosphere is probably greater now than at any time over the last several hundred thousand years. The outcome of this experiment is uncertain. Are we ready and willing to take the risks? So far the answer is yes, because in spite of all the talk about global warming, greenhouse gas levels in the atmosphere continue to increase. This is especially relevant for the people of the United States who emit more greenhouse gases per person than any other large nation on Earth. By the way, if you are one of those people who believe that even though adding greenhouse gases is probably not a good thing, but think we should wait to deal with the issue until we are more sure that greenhouse gases are causing us problems, you need to keep in mind that there will likely be no "quick fix". Once released into the atmosphere, greenhouse gases remain for quite some time, and there is a significant delay before the complete climate change, at the higher greenhouse gas concentrations, is fully realized. In accordance with those who believe that we should not take the potential risks associated with climate change here is an interesting comparison between possible climate change caused by emissions of greenhouse gases and possible cancer caused by tobacco use.

In reality recent climate change is influenced by both natural variation and human greenhouse gas emissions. It is very difficult to determine the relative influence from each. Much of the debate revolves around the question ... is recent climate change mostly from natural variability or mostly from greenhouse gas emissions? One one side, there are researchers who believe that recent climate changes are mainly due to natural climate variability, which has happened throughout Earth's history, with much less influence from greenhouse gas emissions. Some point to known geophysical oscillations, such as the Pacific Decadal Oscillation (PDO), to explain recent and past temperature changes. They may reason that recent climate changes are just part of natural variations in climate, and humans and most other forms of life have survived past changes just fine. Since the changes are mostly natural, there is not much that humans can do about it anyway. One the other side, there are many climate scientists who believe that, even on top of the natural variability of the climate, something out of the ordinary is happening and humans are to blame due to greenhouse gas emissions. They believe that recent climate change is mostly due to greenhouse gas emissions and we must take steps to reduce or eliminate emissions to avoid unnatural and potentially catastrophic future climate change. The next 30 years or so may help us better determine what is most responsible for for modern climate changes. There are quite a few researchers that are predicting a decades-long period of global cooling based on their assertions that we are beginning a period of lower solar activity and/or a cold phase of the PDO. This contrasts strongly with global climate models that predict continued warming due to greenhouse gas forcing.

Yet another group of people do not deny that temperatures are warming and also believe that it may be caused by human activity (although we cannot be sure at this point mainly because climate models are not good enough to answer this question), but they are unconcerned about the possible consequences. In essense they do not believe the doom and gloom future senarios projected by the IPCC reports. This group wonders why we should go through economic and personal hardships required to signficantly reduce our emissions of greenhouse gases, since in comparison, those hardships will be much worse than the consequences of any climate changes that we may or may not cause. For example see the Newsweek article written by Havard atmospheric scientiest Richard Lindzen Learning to Live with Global Warming: Why So Gloomy? Unfortunately, I am no longer able to find the original opinion piece using a free link. It has been eliminated. However, there are plenty of links to sources that attack Lindzen's originally published piece. In one of those, I was able to find a link to some of the text from the original piece. The title, "Opinion: Global Warming Fears Overblown" is not the same as the original title. It does not even provide proper reference to the author. Here is a link to A portion of Lindzen's 2007 Newsweek Opinion Piece

Here is a recent Zoom presentation from Dr Lindzen that expands upon his views, titled, " The Imaginary Climate Crisis - How can we Change the Message?"

Based on recent public opinion polls, it appears that many Americans implicitly agree with Dr. Lindzen, i.e., although many believe human activity may be responsible for recent climate changes, taking action to reduce greenhouse gas emissions is not considered a high priority, (see Feb 3, 2023 Pew Research Poll of American's top priorities). Internationally, Americans show relaltively low concern about addressing climate change compared with citizens polled in other countries as shown in this Pew Research poll conducted in August 2022. People were asked if they consider global climate change a major threat. Only 54% of US citizens said yes, which was lower than all but one country. Overall, global climate change was considered the biggest threat when all countries are considered, yet US citizens ranked it the least important of the five threats considered.

There are some who take this a step further by claiming that higher levels of CO2 will result in beneficial climate changes for life on Earth. The basis for this argument is that global plant productivity will continue to increase due to the combination of higher levels of CO2 and warmer temperatures. The current concentration of CO2 at over 400 ppm is much lower than it was during past periods, such as the Cambrian Peroid (~550 Million years ago), when it estimated to have been around 6000 ppm. Thus, some say the current global environment is CO2-starved. Life on Earth flourished during this period of higher CO2. Ancient plants grew so prolifically that over time CO2 levels in the atmosphere dropped and much of the carbon accumulated as fossil fuels. These people claim that all we are doing today is returning this carbon back to the atmosphere. Here is an article from NASA, Carbon Dioxide Fertilization Greening Earth, Study Finds, which indicates significant "greening" of the Earth's surface over the last 35 years based on satillite observations.

Several prominent scientists have expressed their belief that the potential benefits of increased carbon dioxide outweigh any risk. Links to two YouTube videos are available below. The first is an Interview with former theoretical physicist Freeman Dyson titled "Carbon Dioxide is Making The World Greener." The second is an Interview with physicist Dr. William Happer from Princeton University titled "World In Midst of Carbon Drought."

There are many diverse opinions on how to deal with the global warming issue. Each of us needs to make up our own mind. Are you willing to make sacrifices now to reduce the potential (and uncertain) consequences of global warming? Personal sacrifices would be consciously limiting your activities which release greenhouse gases (like electric energy use, driving a car or traveling by airplane). Do you support societal sacrifices and regulations to reduce greenhouse gas emissions? Do you feel strongly enough to actively advocate for such regulation? Societal sacrifices would be government regulations that force individuals and companies to reduce emissions of greenhouse gases.

Topic Outline for Further Discussion

This outline is used to stimulate discussion in the lecture class. You are not expected to study over and understand all the issues presented below. These are just some additional topics to think about. There are many other debatable topics within the anthropogenic global warming issue than are presented here.

  1. Since we are unable to accurately predict future climate changes due to adding greenhouse gases, surprises are possible. There is the real possibility that future climate changes due to anthropogenic greeenhouse gas emissions will be even more severe than the predictions of current climate models.
  2. Ocean acidification is sometimes called the "other CO2 issue." A good portion of the CO2 emitted into the atmosphere by human activities ends up in the oceans. The absorption of CO2 by the oceans could in fact be slowing down the potential climate changes related to human emissions of CO2. As CO2 is dissolved into the ocean water it alters water chemistry, making it more acidic and lowering its pH. This may affect the life cycles of many marine organisms. This issue is gaining attention, but as with other possible effects of human emissions of greenhouse gases, the outcome is uncertain. Below are links to two articles, the first discusses the possible negative environmental effects as more CO2 is dissolved into the oceans, while the second claims that global average ocean acidification may not be much of a problem at all, especially when compared with the huge daily swings in pH that have been observed at single locations:
  3. Although Al Gore and and others claim there is a consensus among climate scientists on global warming due to greenhouse gas increases, this is not true at all. This I know from experience. Atmospheric and climate scientists have debates all the time about the effects of increased greenhouse gases and how much we should be concerned about it. The often repeated assertation that 97% of scientists believe that human-caused climate change is an urgent problem is false (see the linked article below, which explains the history of this false statement). People like Al Gore like to say things like "the science on [human-caused] global warming is settled" and what is left to do is determine how to reduce emissions. Be careful about the motives of the people who are spreading this myth of scientific consensus on global warming. They are preying on the fact that many non-scientists don't want to bother tying to understand the science behind complex issues like global warming. By claiming consensus among scientists, it gives the public an excuse not to think about the issue. It is as if Al Gore is saying, "just believe me, this issue is far too complex for you to understand." Scientists need to be able to explain complex environmental issues to the public.
  4. Try to think about the issue objectively and not emotionally. Just becuase we are perturbing our environment does not guarantee disaster.
  5. There are people and organizations who will tell you that their main concern is the the environment and negative effects of global warming, but in reality they have hidden agendas.
  6. You should realize that humans are significantly altering the global climate in a variety of ways besides the radiative effects of adding greenhouse gases. When we put all of our focus on carbon dioxide emissions in terms of its perturbation to the greenhouse effect, we are neglecting other, and potentially more important, aspects of the impact of human activities on climate. If we are serious about mitigating anthropogenic climate changes, then we need to consider the effects of everything that we do, not just the radiative effects of added greenhouse gases. Examples of other human activities that influence climate changes include landscape changes, aerosol production, and the widespread use of fertilizers. Below are links to two articles, written by Roger Pielke Sr., which discuss how we are largely ignoring some human activities that have damaging impacts on the environment, since all the focus is on greenhouse gas increases and changes in global average temperature.
  7. In focussing too much attention on reducing carbon dioxide emissions, we often ignore adaptation strategies that could save millions and reduce our exposure to loss in the future (see Lifting the Taboo on Adaptation).
  8. Are we willing and able to do what it would take to significantly reduce the possible effects of global warming?
  9. Perhaps becuase anthropogenic global warming and its possible effects remain uncertain, we should focus on making changes that make sense even if there were no global warming fears. We need to sensibly plan for the future energy demands of the world as fossil fuels will run out someday. I think that most people agree that conservation, preservation, and the development of sustainable alternative energies are important and should be carried out. However, we should try to avoid making hasty and poorly thought out decisions on energy policy that only marginally influence possible anthropogenic global warming, but have far reaching negative impacts on people, such as the widespread production and use of corn-based ethanol or imposing high "energy taxes" that will be disproportionately paid for by the poor. For example, you may wish to read Protecting the Poor from Climate Change: Which Voices Count for another perspective.

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