The Greenhouse Effect, undoubtably you have heard of it by now: The inexorable warm up of the planet Earth due to the emission of man-made Carbon Dioxide and other gases. While I am no expert on this subject, I have an all-around knowledge of what it is, and why it is so hard to say whether or not we are actually undergoing greenhouse warming. Here is a general rundown of the Greenhouse Effect, with the astronomer in mind.
As you know, the planet Venus is enshrouded by clouds. Venus is also very, very hot by our standards, with temperatures of many hundreds of degrees fahrenheit by the most conservative estimates. The two are not coincidental!
Have you ever noticed on a night when you are observing the stars, that the temperature tends to be cooler, than when it is cloudy? This “sealing in” of the heat, is a temporary “Greenhouse Effect”. It happens all the time. Sunlight, or shortwave radiation, comes in during the day, but in our example, is trapped by the clouds at night, so that the ground is not able to “see” the sky, and thus radiate away the daytime heat back to space as “long wave” radiation. This is exactly how a greenhouse operates.. the sunlight comes in as shortwave radiation, but the GLASS inhibits the long wave radiation from returning to space.
On Venus, the bright cloud deck of the day is able to allow just enough brightness in to warm the planet, but the clouds and gases trap in the heat on a permanent basis. On Earth, man-made gases have the same effect as the glass walls and ceiling of a greenhouse: They do not let the long-wave radiation return to space. The higher the carbon dioxide level, the more difficult it should be for the heat of the day(s) to escape out, leaving some to suggest that we will eventually follow Venus down the road to planetary doom.
It probably isn’t quite as serious as that, firstly, and obviously because we are further from the Sun. Nonetheless, the Greenhouse effect, if it came to full fruition, could be devastating to the Earth in many related ways, not directly from the warm-up itself.
The biggest quarrel in the Meteorological community of all time has to be whether or not we have already begun Greenhouse warming. You might think it would be obvious, but the problem is that there is already a swing in temperature globally from time to time that is natural. In fact, while we ARE currently as warm as the Earth has ever been to our knowledge, it has happened before, and may just be part of a normal cycle. The Greenhouse Effect will not really be able to be detected for sure until AFTER it has happened, almost by definition. That is to say, we have to look back in time to see a significant period of warming that is uncharacteristic of any normal swing in climate. If we do not know that the Greenhouse Effect is here until after the fact, then also by definition, logic implies we can’t really wait until we are sure it is here to try to stop it from getting out of hand!
A larger number of scientists and climatologists now believe that we are entering a significant “Greenhouse” warming because
a. It is already a very warm period in Earth’s climatological history
b. New, sophisticated computer models are PREDICTING a major warm up due to the excess Carbon Dioxide, of up to 8 degrees Fahrenheit in the next 30 years (globally) But of course, even the computer models disagree, some pointing to a much lower number.
What would really happen though, if there WAS a bit of a warm up, to some.. it seems almost enticing… Well, it is not so much the direct effects of a warm up, as the indirect ones. For instance, the polar ice caps would melt just enough to bring on a very significant rise in sea level… enough to flood some low lying cities around the world. (New Orleans, La., USA, as an example is already below sea level) Also, Hurricane and Typhoon frequency would undoubtably rise from the warm ocean, which helps create them in the first place. Thus, the areas that are already oceanfront, and vulnerable to sea level increases, are now also potentially threatened by Hurricanes, which could bring that seawater onshore even further, and more frequently.
Other indirect effects of a “greenhouse” warm up include climate shifting so that many species of animals and especially trees will be totally relocated, or threatened. Also, this shifting around could bring devastating areas of drought and/or heat (many predict the Midwestern United States would suffer) to established agricultural areas around the world. On the bright side, both man, and nature have adapted well to gradual climate shifts before. Even if there is an overall trend “upward” in temperature, we may have time to adjust to the change. Also, based on some predictions in the 1960s, we could have already been much warmer, globally, than it is today.
Meanwhile, Mother Nature seems to have a way of compensating for swings in climate. It is quite possible that a series of volcanic eruptions, for instance, could substantially halt a major global warming at the same time that man begins to use less fossil fuel in the future, thus putting a lid on the Greenhouse effect. (Volcanic eruptions spew particles into the Stratisphere where they are trapped for years, to the detriment of astronomers. However, this “cloud” acts to prevent incident solar radiation more than keeping the heat locked in, thus it cools the Earth. In the most extreme instance, this could cause a dramatic cooling of the Earth)
So, overall, the debate revolving around the Greenhouse controversy boils down to more of the questions such as: “how bad is Greenhouse warming?” rather than: “is Greenhouse warming for real?” My opinion is that this matter should be taken very seriously, because a cure “better late than never”, may just not be enough!
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Have you seen “The Great Global Warming Swindle” on YouTube? It really made me think twice about man-made global warming. There’s no doubt that the climate is changing, but is it really man-made? Is it really getting warmer, rather than getting colder at the moment?
Who benefits from the man-made global warming theory? There getting ready to create a global “Carbon Tax” that’ll be payable directly to the United Nations. What does this have to do with globalism?
The atmosphere of Venus is 90 times that of the Earth. It is also much closer to the sun than the Earth is. These 2 factors alone would account for the much higher temperature of Venus’ atmosphere.
As far as CO2 driving global warming, Venus’ atmosphere is about 95% CO2 while the Earth’s CO2 content is .0035%. I would also add that the atmosphere of Mars is also about 95% CO2, but due to the same comparisons between Venus and the Earth that I have just made is the reason why Mars is so much colder (less dense atmosphere and distance from the sun).
To compare Venus and the Earth and say we are headed the way of Venus (as far as global warming) is like comparing apples to chunks of lava.