|MadSci Network: General Biology|
You have touched on several interesting issues in your question and I will try to respond to each of the individually. First, however, it seems to me that what is really of interest to you is the the interaction of people with their environment and the possible problems caused by mismanaging that environment. This is a VERY complex topic and I certainly don't have enough time to go into it here. In your comments about the effect of deforestation on O2 concentration, however, you have demonstrated the basis of one of the disciplines used to study this topic that you may be interesting in researching further. The study of elements and how they cycle through the hydro-, terra-, bio- and atmosphere is called biogeochemical cycling. When you talk about oxygen and deforestation you are talking about the cycling of oxygen from the biosphere to the atmosphere (get it?). I did a quick search under biogeochemistry and came up with several good sites. A good place to start because of their copious links is the Global Change Research Information Office: http://gcrio.ciesin.org/ Check it out and dive into the topic to your heart's content. The site has links that are of interest to the laymen as well as the researcher. Now, for your specific questions. First let me say that I wouldn't be too worried yet, especially about the O2. The concentration of oxygen in the atmosphere is greater than the human lung's capacity to remove it. When you exhale, you release not only CO2 and N2 but a significant portion of the O2 you just breathed in. Although the process is concentration driven (ie the higher the O2 concentration, the more readily O2 is absorbed into the blood stream) I don't believe that levels have gotten low enough to cause difficulty breating. Secondly, O2 is a constantly renewable resource. As long as there are plants living on this earth there will be production of O2 - and by plants I mean not only trees and grass and other terrestrial species, but also all the photosynthesizing aquatic organisms. Often people don't realize what a HUGE part these creatures play in the global cycling of all the most important elements. In fact, some scientists believe that deforestation in certain areas of the world and the resulting increases in CO2 will stimulate productivity in other areas of the world including the oceans (note: this is one theory of many and I want to be clear that I'm not trying to endorse one idea over another - frankly, I'm not an expert on this topic and can't give you a fair evaluation of all the current theories). As for the ozone and pollution issues, it is frankly hard to say. Both of these issues and how to deal with them are not relegated to the field of science only. Unfortunately (or fortunately?) one must also consider both politics and economics as well as the environment when talking about any such issues. Is there a hole in the ozone layer? Most definitely yes. Is it a serious problem? I'm not sure, it could be a huge problem that we might be able to fix. The more me learn about it and the more we remediate our practices the more able to come up with solutions. As for pollution, what do you consider pollution? By some definitions, there it's a single place on this earth that isn't polluted to some degree. That may sound scary but think about this - just your breathing could be considered pollution (you release CO2 after all). I guess what I'm getting at is that there are no concrete answeres. The world is an incredibly complex place. Should we be worried about our environment, are we irreversibly changing our environment for the worse? I would say no to both. I don't think we have gone so far as to ruin this planet for the future and while I would say don't 'worry' about it I would say be 'concerned'. Keep informed about environmental issues and look at ALL sides of the problem - there is always more than one credible argument for any issue. Educate yourself and make decisions appropriate to what you have learned and believe. If everyone takes this responsibility I think we would be surprised at how fast we could solve of the most pressing issues of our time.
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