Friday, February 16, 2007

Factsheet

Cross-posted with Thoughts on Global Warming.

Wondering why there's been so little posting lately? Below is a BIG factsheet about global warming, the atmosphere and other facts about Earth. This is was not made by anyone else or for anyone else. This is a Thoughts on Global Warming/Thoughts on the World exclusive.

--------------------------------------------------------

The Troposphere, the Stratosphere, the Mesosphere, and the Thermosphere make up the atmosphere of the Earth. The Troposphere exists from the surface of the Earth to 15 kilometers above the surface of the Earth. The temperature ranges from 15 degrees Celsius at the surface to negative 60 degrees Celsius at the top of this layer. Life exists at this level. The greenhouse effect, natural and enhanced, takes place here, as does the weather. Above the Troposphere is the Stratosphere. Temperatures rise from negative 60 degrees Celsius at the bottom of the Stratosphere to zero degrees Celsius at the top of the Stratosphere. The Stratosphere occurs from 15 kilometers above the surface of the Earth to 50 kilometers above the surface. The ozone layer, which protects Earth from harmful ultra-violet radiation, exists in this layer. The layer above the Stratosphere is the Mesosphere, which ranges from 50 kilometers above the surface of the Earth to 85 kilometers above the surface. The temperature sinks from 0 degrees Celsius to negative 70 degrees. This layer protects Earth from meteoroids. This is the first layer that meteorites encounter that is dense enough to create enough friction to burn up meteoroids before they get to the surface. The layer above the Mesosphere exists from 85 kilometers above the surface to 600 kilometers, where it melts off into space. It is known as the Thermosphere. Temperatures here can reach up to 2,000 degrees Celsius, and most satellites are in the Thermosphere. Throughout all of these layers, the further one is from the planet, the less the pressure and density is.

As mentioned previously, pressure and density consistently decrease throughout the layers. Pressure is strongest closest to the Earth, in the Troposphere. This is because there are three layers above it pushing down on it. The Stratosphere has the second greatest pressure because it has two layers pushing down on it, and et cetera. Density is also greatest in the Troposphere, second greatest in the Stratosphere, third greatest in the Mesosphere, and least great in the Thermosphere. The Troposphere is densest because of gravity. Gravity is stronger closer to the Earth, and consequently more matter is pulled down closer to the Earth, making the closest layer to the surface the densest. Temperature is unlike pressure and density. It varies from layer to layer. In the Troposphere, temperature lowers when ascending. But after entering the Stratosphere, temperatures begin to rise. This is caused by the ozone layer. The ozone layer absorbs ultraviolet radiation originating from the sun. When absorbed, the ozone molecules (O3) release heat, heating the layer. But in the Mesosphere, temperatures begin to drop again as it is further from the Earth. Oppositely, the Thermosphere warms up instead of cooling down. Sun strikes nitrogen and oxygen molecules in the Thermosphere first. The oxygen and nitrogen molecules convert energy from sun into heat.

The majority of the pure dry atmosphere is nitrogen (N2), at 78.084 percent of the atmosphere. Oxygen (02) is 20.946 percent of the atmosphere, and Argon makes up 0.9340 percent. None of these gases are greenhouse gases, but carbon dioxide (CO2), which makes up 0.0383 percent of the atmosphere, is. Neon (Ne) makes up 0.00182 percent of the atmosphere; Helium (He) is 0.00053 percent; Krypton (Kr) is 0.00012 percent; Xenon (Xe) is 0.00009 percent; Hydrogen (H2) is 0.00005 percent. Neither neon, nor helium, nor krypton, nor xenon, nor hydrogen is a greenhouse gas. Nitrous oxide (N2O), which makes up 0.00005 percent of the atmosphere, is a greenhouse gas, as is methane (CH4), which is 0.00002 percent of the atmosphere.

Energy from the sun travels to Earth as electromagnetic waves. It first encounters the atmosphere. Some infrared radiation and most ultraviolet radiation are reflected by greenhouse gases in the atmosphere. Some of the rays are reflected by clouds, gases, or dust particles. The energy that gets past the atmosphere next encounters Earth’s surface. Some of it is reflected back into the atmosphere, while the rest is absorbed. When the surface is heated, it radiates some of the energy back into the atmosphere as infrared radiation. This radiation cannot escape back into space. Instead, much of it is absorbed by greenhouse gases. These gases, such as water vapor, carbon dioxide, nitrous oxide, and methane make life on Earth possible through this effect. This process by which gases hold heat in the air is called the greenhouse effect.




Energy from the sun enters Earth’s atmosphere, and while some is reflected, some energy gets through. Some of that energy is reflected by the surface, and some is absorbed by the surface. That heats the surface. When heated, it is reemitted back into the atmosphere, and absorbed and kept in by greenhouse gases. This is known as the greenhouse effect.


The most common greenhouse gas is water vapor (H2O). The second most common gas is carbon dioxide. Methane, another greenhouse gas, is 60 times as effective of a greenhouse gas as carbon dioxide; a methane molecule absorbs 60 times as much energy as a carbon dioxide molecule. Nitrous oxide, also a greenhouse gas, is 270 times as effective as CO2. This is misleading; neither methane nor nitrous oxide is the biggest cause of the enhanced greenhouse effect. Carbon is .934% of the atmosphere. To be more effective, the gas multiplied by how many more times it is effective has to be greater than the amount of carbon dioxide in atmosphere. Methane is .00002 percent of the atmosphere, and 60 times as effective as CO2. .00002 multiplied by 60 is NOT greater than .934. Neither is .00005 multiplied by 270, how much nitrous oxide there is and how effective of a greenhouse gas it is.
The greenhouse effect is a natural effect. Respiration of plants and animals, volcanic eruptions, decomposition of organic matter, wild fires, and the passing of gas by animals, particularly cows, are all causes of the greenhouse effect. When plants and animals breathe, they release carbon dioxide into the atmosphere. Volcanic eruptions release methane. All organic matter contains carbon dioxide. When it decomposes, carbon seeps out. Wild fires break down plants and animals, freeing the carbon all at once. Flatulence contains methane, a greenhouse gas 60 times as effective as CO2. These natural causes all release greenhouse gases. But now, because of humans, there are more greenhouse gases in the atmosphere, leading to an enhanced greenhouse effect. As human populations have spiked, so has the need for meat. Because of this, there are more and more cows being bred. Cows eat all day. By eating grass, not only are they killing plants that could be taking in carbon dioxide, but also grass makes them release more methane. Another reason for the enhanced greenhouse effect is cars. Cars release huge amounts of CO2. Clear cutting forests and burning fossil fuels like coal also contribute to the enhanced greenhouse effect.


The carbon cycle. Carbon moves along the land, oceans, atmosphere and the planet's interior. Oceans, fossils and fossil fuels, dead organisms, waste products, decaying organism, photosynthesis, respiration, and factory emissions cycle it along.
There are two parts to the carbon cycle. One operates over shorter time scales (days to years), while the other over longer time scales (thousands of years). This cycle takes place as carbon is moved along the land, oceans, atmosphere, and Earth’s interior.

Biology is an important factor in the movement of carbon into and out of the atmosphere. Through photosynthesis, green plants take carbon dioxide out of the atmosphere and use it to make food. Plants “burn” the food through cellular respiration. Cellular respiration releases the CO2 back into the atmosphere. Once these plants die, they return the carbon dioxide to the atmosphere. Sometimes the plants get eaten instead of dieing. The carbon is then released back into the atmosphere through the animal’s respiration. Animals also play a part. During animal respiration, carbon is put in the atmosphere. When animals die, the carbon that was in them is released into the atmosphere. Another example of the short term carbon cycle is seasons.

Photosynthesis and cellular respiration also play a part in the long-term cycling of carbon. Land plants help make soil, leading to the slow removal of carbon dioxide from the atmosphere. In the oceans, certain single-celled plants and animals convert carbon into shells made of calcium carbonate (CaCO3). When the shelled creatures or plants die, their shells eventually decompose, releasing CO2 back into the cycle. They can find their way out through volcanoes, mid-ocean ridges or other ways. If a plant creates more food than its cellular respiration, organic matter gradually gathers. Over millions of years, this buildup can become coal and oil. The coal and oil sits undergrounds for hundreds or thousands of years. Carbon dioxide is held in plants. Consequently, wild fires or when forests are cleared for farming, carbon is released into the atmosphere. Ocean temperature also plays a part in the carbon cycle. Cold ocean waters remove CO2 from the atmosphere. Cold, downward-moving currents—such as those found in the North Atlantic—absorb carbon and transfer it deep in the ocean. Warm waters cause the surface to release CO2. Upward moving currents—such as those in the tropics—bring carbon dioxide up from the depths and release it into the atmosphere.

Cars have radically changed the carbon cycle. Most cars run on gas, which is created from a fossil fuel, oil. When it is burned for energy, carbon dioxide is released into the air. Essentially, cars take CO2 in the ground and put it in the atmosphere. That creates more work for plants and oceans taking carbon out of the atmosphere.


A long term view: Temperature and carbon dioxide levels of the last 450,000 years worldwide. As can be seen, temperature generally follows the level of carbon. In the top right corner, the current amount of carbon dioxide can be seen. It is at unprecedented levels. The temperature is expected to follow.





A short term view: Carbon dioxide levels of Mauna Loa, Hawaii. Over the last 40 years, carbon dioxide levels have steadily increased.

Climate has changed many times throughout all of history. One cause of this is continental drift. Continents slowly move around the surface of the Earth. Not only does the position of a continent affect its own climate, it affects the whole world. On a global scale, continents can change the currents and routes of oceans and global winds. When continents collide, they sometimes create mountains. These mountains change climate by blocking winds. Another natural cause of climate change is volcanoes. When volcanoes spew out ash and carbon, they strengthen the greenhouse effect. In the early stage of Earth’s history, there were thousands of volcanoes. They had a huge impact on the climate. The sun also has a huge impact on the weather of Earth. The sun doesn’t always produce the same amount of energy, causing the amount of energy in and around the Earth to vary. The variation in solar output is primarily based on cycles of sunspot activity. Sunspots are dark areas of magnetic disturbance on the sun’s exterior. It has been proved that when there are more, bigger sunspots, the sun’s energy output is highest. This occurs about every 11 years. Bolides, such as comets or asteroids, can also have a huge impact on the atmosphere and environment. If one were to fall on land, a dust cloud would rise and possibly block out the sun. Following wildfires caused by the hot temperatures, most creatures would be killed off by the dark bolide winter. Another effect would be the nitric and nitrous acids released. The acids would destroy the ozone layer. The axis of the Earth wobbles, and wobbling can change the climate. It wobbles through a complete revolution every 26,000 years, an event known as the precession of the equinoxes. The angle of the tilt of the axis compared to the plane of orbit also makes a big difference in global weather. When the angle is smaller, sunlight strikes various points on Earth more evenly and seasonal differences are smaller. When the angle is larger, the seasons are more pronounced. Glaciers are more common when the Earth’s tilt is at a smaller angle. The orbit around the sun also is a factor in worldwide climate. When the orbit is more circular, there is less a more equal amount of the levels of solar energy received by different parts of the Earth than when the orbit is elliptical. Additionally, a more elliptical orbit means the summers and winters are longer, and springs and falls are shorter.

As mentioned previously, in the short term, seasons are part of what controls the climate. Also in the short term, photosynthesis and cellular respiration have an effect on short term climate. So does decaying organisms. When organisms decay, they free carbon dioxide into the atmosphere. Fossil fuels hold CO2 in the earth. When factories or cars burn them, they release carbon back into the atmosphere. Oceans also play a part. Cold waters absorb CO2 and put it at the bottom of the ocean. Warm waters take CO2 and put it back in the atmosphere.
Climate change in the last 100 years differs from previous climate changes. There has been no asteroid, continents have barely moved, volcanoes are less active now than they were 2 billion years ago, Earth’s orbit and its axis has not varied hugely, and the sun remains in the same pattern it has been going in for billions of years. The major change has been the level of carbon. And it’s caused by humans. Ever since the industrial age, carbon dioxide levels in the atmosphere have been spiking. This can be seen on long-term carbon graph. Temperature is also rising. 1996 was the hottest year on record. If nothing is done, the level of carbon may continue increasing. Venus, Earth’s planetary neighbor, is very similar to Earth in size and other attributes. One major difference is the level of carbon. The level of carbon on Venus is 100 times the level it is on Earth. Because of this, Venus is extremely hot. If that happened on Earth, life would be eliminated.

The Industrial Revolution brought new technology to the world, with an expensive price. The machines used since the Industrial Revolution have put massive amounts of CO2 in the atmosphere. Because carbon is a greenhouse gas, when there’s more of it in the atmosphere, the greenhouse effect is stronger. More heat is trapped, and the climate is hotter. This is the enhanced greenhouse effect. Cars and factories are major causes of the enhanced effect. The enhanced greenhouse effect is a stronger, human influenced, greenhouse effect. It is causing global warming.


Global warming is the gradual rise of the temperature on Earth. Greenhouse gases have amassed in the atmosphere. These gases led to the enhanced greenhouse effect, which in turn led to global warming. The effects can already be seen. Recently, a portion of ice the size of Rhode Island broke off Antarctica and melted. Other parts of Antarctica have been melting, as has another one of the world’s biggest ice block: Greenland. 1997 was the hottest year in the world on record. 2006 was hottest year in the United States. Droughts are increasingly common around the world. Global warming is having real and serious consequences.


The Goldilocks principle is the story of three planets: Venus, Earth and Mars. Venus has massive amounts of carbon; 96.5 percent of its atmosphere is carbon dioxide. It has an atmosphere and a greenhouse effect. And because there is so much CO2, the average temperature is 477 degrees Celsius. Without the greenhouse effect, the average temperature would be -46 degrees. Then there’s the Earth. The carbon dioxide is currently .934 percent. The average temperature is 15 degrees. With an enhanced greenhouse effect, the temperature would be 33 degrees higher; a steaming 48 degrees Celsius. Mars is the opposite of Venus. Mars is 95% CO2, but has no atmosphere, therefore no greenhouse effect. Mars’s average temperature is -47 degrees. Without greenhouse gases, the temperature would be -104 degrees Celsius. Earth could end up like either of these planets, but because of global warming, the more likely candidate would be Venus.


Cars are a major contributor to the enhanced greenhouse effect. When burning fossil fuels, they release carbon dioxide into the atmosphere. There are a large number of cars already, but the amount is growing. With India and China’s booming economy, additional middle and lower class are buying cars. And it’s not just India and China. Some of the cars that are being bought are less fuel efficient, and most of the less fuel efficient cars are SUVs. Not just thriving in the U.S., they are pumping out CO2 in developing countries too.


Contrary to popular belief, cars and factories are not the only origins of global warming and the enhanced greenhouse effect. Deforestation is another way humans are putting carbon in the atmosphere. When trees are cut down for farming, they slowly decompose and leak carbon dioxide into the atmosphere. Sometimes farmers will burn trees to get them out of the way. This puts the CO2 out there even faster. By burning, the CO2 doesn’t seep out, but bursts. Either way a farmer does it, they still get rid of trees. Trees also take carbon dioxide out of the air. Deforestation is doubly harmful. As unlikely as it sounds, cow flatulence is a huge problem. Human population has risen rapidly in the last 100 years, and so has the demand for meat. Extra cows are being bred. The only thing cows do all day is eat. Cows eat grass, which is a green plant. Green plants take carbon dioxide out of the atmosphere. Cows also pass gas a lot. Gas is composed of methane, which is a greenhouse gas. This methane is part of the enhanced greenhouse effect.


- The 2005 estimated U.S. carbon dioxide emissions are 6,008.6 million metric tons.
- The change in carbon dioxide emissions in the U.S. since 1990 is 20.4 percent.
- The effects of global warming can already be seen:
- The number of Category 4 and 5 hurricanes has almost doubled in the last 30 years.
- The flow of ice from glaciers in Greenland has more than doubled over the past decade.
- Malaria has spread to higher altitudes in places like the Colombian Andes, 7,000 feet above sea level.
- Most of the United States has already warmed, in some areas by as much as 4 degrees Fahrenheit. In fact, no state in the lower 48 states experienced below average temperatures in 2002. The last three five-year periods are the three warmest on record.
- September 2001 to February 2002 was the second driest six-month period on record for the Northeast.
- Vermont, New Hampshire, Rhode Island, and Massachusetts each got more than double their normal monthly rainfall in June 1998.
- In 2003, extreme heat waves caused more than 20,000 deaths in Europe and more than 1500 deaths in India.
- According to NASA, the polar ice cap is now melting at the alarming rate of nine percent per decade. Arctic ice thickness has decreased 40 percent since the 1960s.
- Global sea level has already risen by four to eight inches in the past century. Scientists' best estimate is that sea level will rise by an additional 19 inches by 2100, and perhaps by as much as 37 inches.




2 comments:

Dan Johnson said...

Here are a couple of corrections to the figures in the text above - I think these are just typographical errors. The factsheet says:

"... Neither of these gases are greenhouse gases, but carbon dioxide (CO2), which makes up 0.934 percent of the atmosphere, is. Neon (Ne) makes up 0.033 percent of the atmosphere;...".

Actually, CO2 is 0.038% (ca. 380 ppm) of the atmosphere, and Neon is actually about 0.00182% (18.2 ppm). Did something get a little mixed up in the typing? Argon makes up 0.93% (by volume), and maybe that is the source of the error. These are minor editorial changes that can be easily made. The rest is a good summary of the issues.

Simmons said...

Hmmm... That's interesting and will be looked into, thank you.