Tipping point?

Discussion of the distribution and abundance of living organisms and how these properties are affected by interactions between the organisms and their environment

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King Cobra
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Post by Draco » Fri Mar 07, 2008 11:05 pm

Darwin420 wrote:This is how I look at it. I am in environmental resource this year and switching into environmental biology next year. As we know the earths climate is changing, and yes, we have found a positive correlation between greenhouse gases (i.e. carbon dioxide, water vapour, methane etc.) and temp increasion - as the greenhouse gasses go up so does mean temperature. However, say that we do somehow stop using coal plants, switch to hydrogen fueled cars and reduce our greenhouse emissions, it will only prolong the (somewhat) stability of the earth's climate. We have endless evidence from geological records, paleoclimatologist that the earths temp naturally changes. Example: Mid eval heat wave, the last ice age roughly 10 000 y.a. Heck, we can even go back to the dawn of time roughly 4 billion years ago - the Haden eon when the whole earth was at sky rocket temperatures, the ground was comprised of lava!!

The earth naturally changes, and the fittest species survive, we can try (and should), reduce greenhouse emission (emitted by human activity), but at the end of the day, climate change happens naturally, and it will eventually occur to a level which whipes out the human race - sorry to say so folks.

Than again, this is just my opinion based on a series of facts.

Do you study geology as well?

Cat wrote:I think it is more to the point that we interrupt most nature’s attempts toward climate equilibrium. As I understand it, for the climate to “right itself” dramatic events have to occur. The problem is that we are able to squash most of those smaller events (since they are inconvenient to us) and the next event has to be larger. If we stop interfering, however, it is a good possibility that a large part of human population will be wiped out. It is unnatural for us to consciously allow that to happen, and, of course, polluting planet further does not help any.
In regards to the tipping point, I agree with Draco.

The only major events that will have any true effect are volcanic eruptions of the magnitude of krakatoa, which caused global cooling of about 5 degrees.
The problem is such events are rare and very dangerous to the people near by.
Why can't this be left blank?

King Cobra
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Re: Re:

Post by Cat » Sat Mar 08, 2008 3:09 am

Draco wrote:The only major events that will have any true effect are volcanic eruptions of the magnitude of krakatoa, which caused global cooling of about 5 degrees.
The problem is such events are rare and very dangerous to the people near by.

Not really. You are looking only at events that directly related to temperature, but considering a lot of other – smaller events – is also very important.

Wild fires are very important to forests (those that prone to have them), but very inconvenient to us.

1. They produce nitrogen oxide that is required for seed germination
2. They remove the leaves of older trees to give light to seedlings
3. Ashes provide nutrients

Ultimate outcome of squashing wild fire is less photosynthesis since younger plants do a lot more when they need to grow than the old ones.

Grass lawns may look pretty, but again less photosynthesis than common weeds (but we would not like those!).

Lately, someone came up with the way to alter hurricanes, but those are also important to regions that have them! Seed dispersal; removing old, frail, and rotting trees; and most of the time brining much needed rain! Of course, when hurricane does occur, cleaning up after it is also a bad idea from that stand point (and we really would not like that mess!).

These are just a few examples related photosynthesis (and, therefore, to carbon dioxide levels) where each event on its own does not have a drastic effect, but rather cumulative effect over years (like effect of pollution).

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Re: Tipping point?

Post by MichaelXY » Sun Mar 09, 2008 6:30 am

I watched a BBC film entitled the Big Chill. I wrote a review.

“The Big Chill”,

presented by BBC, and Science & Nature TV radio, discusses the potential impacts of global warming on Earth.. The film begins with a hypothetical situation in which a future Britain could be like the French Riviera.

The film quickly segues into interviews with geologist disputing this scenario. In an interview with researcher, Dr. Bill Turrell, he paints quite a different scenario. Turrell, a man who has been studying the ocean current for many years, has noticed a drastic change in the salinity content within the currents of the Gulf Stream waters. The implications posed by Turrell and other scientist, present catastrophe for planet Earth. The film compares the workings of the Gulf Stream to that of a conveyor belt. A continuous cycle of warm water flow fed by the gulf into the northern Atlantic is fueled by the higher salinity content off of Britain’s shore. The salinity contributes to a sinking effect of the warmer Gulf flow. A notable increase in global temperatures has precipitated an increased melting of the ice caps of Greenland. The melting of the ice in turn has begun to dilute the salty brine of the Atlantic. The causative effects of the diluted waters could pose a cessation of the Gulf Stream, and this would in turn create a freeze condition for the European continent.

I have developed my own opinions based on the film. The Gulf Stream conveyor belt seems somewhat analogous to the homeostatic temperature control mechanism of the human body. As with the body, when an increase in body temperature is detected the body responds with a sweating reflex to provide cooling for the body, the Gulf Stream warm water currents are reduced by the melting caps, and in response, the salinity reduces, and the climate temperatures lower, which in turn starts a freeze on the ice caps. As the ice sheets freeze, less fresh water is introduced into the Atlantic, thus salinity once again raises, the Gulf Stream conveyor belt resumes, and temperatures return to normal. The question then becomes: How long are these cycles.

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Re: Tipping point?

Post by Darwin420 » Sun Mar 09, 2008 6:37 pm

To Draco's comment: I have taken a course in Earth Science, which is an interdisciplinary course that deals with geology, animal evolution, cell biology, chem it is just a very broad course that deals with a lot of stuff - not my favorite.

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