A Global Warning?
On January 27th, on the History Channel, I watched a show called “A Global Warning?” which was on global warming, its effects, and what society can do to reverse the effects.
The first portion of the show talked about the history of global warming and how scientists can prove it just by looking at the past. The scientists interviewed are quoted as saying, “To look into the future, we must look into the past (in this case the past 650 million years).” 650 million years ago there was a period called “Snowball Earth”. During this period, ice covered the entire globe…that’s right, the ENTIRE globe including the equator. CO2 levels at this time dropped significantly, thus causing the temperature to decrease and the formation of ice. One aspect of an object that was discussed is called Albedo, which is the ability for an object to reflect sunlight (i.e. the oceans have a low albedo, while snow has high albedo). The scientists proved this by placing a black square and a white square on the surface of the snow, in the North Pole. They let the two squares sit in the sun for about 5 minutes; when they came back and took the temperature of each, they found that the black square was 99 degrees fahrenheit, while the white square was the same temperature as it was outside (I believe it was around -25 degrees). The scientists then predicted a scenario that could occur once the heat of global warming passed. In this scenario, the snow would cover the surface of Earth and its major cities, and after some time, the snow would then turn to ice causing possible power outages, the taking away of our food resources, etc.
After the commercial, the program comes back to describe how Earth came out of the “Snowball”. Below the crust, the planet began to experience increases in convection, thus an increase in volcanic activity at the surface. Because volcanoes dump tons of CO2 into the atmosphere, Earth began to warm. The lava fields of Siberia poured out magma for 1 million years causing the CO2 levels to increase (about 10 times the amount of current CO2 levels). About 250 million years ago the Earth goes to an extreme, so extreme that the surface became hot, partched deserts. 95% of all Earth’s species went extinct, also known as “The Great Mystery” from a geological standpoint in the rock layers. It was becuase of this increase in the temperature that caused not only the Earth to heat up, but it also choked the animals to death.
Over the next few million years, the planet began to cool. But about 55 million years ago, the temperature again increased but this time it was not because of CO2. In 2004, scientists discovered a water fern in a core sample from the arctic. They found that at the time of the water fern, the arctic was actually tropical, and that volcanic eruptions + oceanic bursts of methane (which is 26 times more potent of a greenhouse gas then CO2) = the increase in temperature. As of right now, about 3,000 times the amount of methane found in the core is actually trapped in its solid form (Methan Hydrate) at the bottom of the ocean, marshes, bogs, etc. That means that if the water was to warm up, significantly, then the Methane is realised into the atmosphere…and if this happens, we could be doomed! Not only is Methane a dangerous greenhouse gas, but it is also flammable. It could spell disaster for the planet on a nuclear scale, as far as the energy realised from the explosion.
So, exactly how fast are the oceans warming? Scientists have found out this by how fast the corals, in the various reefs around the world, are growing. To analyze coral is like analyzing the age of a rock layers, the wider the distance between the bands the older fast it was deposted (in this case, growing). A group of scientists took a sample from a coral in the Florida Keys, and the years from the 1700’s to the 1970’s. They found that the coral bands were thinner in the 1700’s then in the 1970’s (thus, 1970’s = warmer then 1700’s).
About 125,000 years ago, sea levels rose and fell multiple times. James Kroll discovered that because of the gravitational pulls from the planets, moon, and sun…that this causes a “tilt” and change in the orbit around the sun, thus the seasons change or are more extreme/at different times/last a lot longer. When the orbit becomes elliptical, the Earth should be cooling, but the opposite is currently happening. 3 feet of sea rise would impact major coastal cities like Miami, Athens, London, Shanghi, and countries like Bangladesh that are close to sea level. But if the sea rise 20 feet, scientists don’t even want to imagine this possibility. Proof of this can be seen in the effects of Hurrican Katrina, in 2005…and just imagine if the sea levels were just a few feet higher, how much damage would have been caused.
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