Sunday, July 7, 2013

A Frog in Boiling Water

Here is summary of the information Al Gore presents in An Inconvenient Truth

1. What image started the modern day environmental movement?

A photograph of the Earth taken from space by Apollo 8 started the modern day environmental movement. This is because the idea of the world as a finite and describable thing was so profoundly humbling.

                                    "Earth rise"

2. What is considered the most vulnerable part of the earth system?

According to Al Gore, the most vulnerable part of the Earth’s ecosystem is the atmosphere. The atmosphere is so thin that volumes of pollutant coming from Earth’s surface can actually change atmospheric chemical composition.

3. Relatively speaking, compared to the earth, how thick is the atmosphere?

The metaphor used in the video is of a globe covered in a thin varnish. The varnish's thickness relative to the globe is approximately the same as that of the atmosphere’s to the Earth.

According to Wikipedia, 99.99997% of Earth’s atmosphere is below 100 km above the surface. The diameter of the earth is approximately 6,371 km according to Google. Thus the atmosphere is 1.57% the thickness of Earth’s radius. So to check Sagan’s estimate, a 12 in diameter globe would have about 1/10th of an inch varnish on it. This seems reasonable in my opinion.

4. How can trapping infrared radiation by the earth’s atmosphere be a GOOD thing?

Trapping of infrared radiation (heat) by Earth’s atmosphere is a good thing because it keeps the planet at a temperature that is livable. Without the trapping of this radiation, the planet would be too cold to support life as we know it.

5. How can trapping infrared radiation by the earth’s atmosphere be a BAD thing?

Excessive trapping of infrared radiation would lead to the Earth becoming warmer than what is optimal to support ecosystems currently in place. The increase in the amount of heat trapped by the atmosphere over time is referred to as global warming.

6. What percentage of people depend on glacial melt for their drinking water?

40% of the global population get drinking water from systems dependent on water from glaciers. For the purpose of this statistic, “dependent” means that at least 50% of the water comes from glacial sources. Examples of areas where physical changes in water availability are noticeable are Italy, Argentina, and Peru.

7. Why is studying ice cores important?

Ice cores reveal a variety of information regarding the ecosystem. Scientists focusing on ice cores are able to correlate layers of ice to certain time periods.  This is similar to what geologists do with rocks layers.

Bubbles of atmosphere are trapped within the ice, allowing scientists to determine the carbon dioxide concentration in the atmosphere during that period of time. By analyzing the isotopes of oxygen in the bubbles, scientists can also determine the average temperature when the snow fell. This way, they can compare carbon dioxide and temperature data and look for correlations.

8. What is the relationship between carbon dioxide (CO2) and atmospheric temperature?

Atmospheric carbon dioxide levels and atmospheric temperature are directly proportional according to ice core analysis. As the carbon dioxide levels have increased over time, so has the temperature.

This relationship proves correlation, but not necessarily causation. One might assume that an experiment to verify the CO2 levels causing temperature spikes would be impossible on a global scale. However, there is a noticeable difference in ice appearance before and after the United States passed the Clean Air Act. This further supports Al Gore’s argument that CO2 emissions are causing global warming.

9. Over what time period have the hottest 10 years on earth occurred?

At the time An Inconvenient Truth was released, the ten hottest years on Earth recorded have all occurred in the last 14 years. It would be interesting to see if this statistic has changed since the video came out in 2006. I am also curious as to what the hottest year on record is currently.

10. As the water temperature under a hurricane increases, what happens to the wind velocity of the storm?

In general, warmer ocean temperatures lead to stronger storms such as hurricanes. In more scientific terms, warmer water increases the wind velocity and storm moisture content. This could be the reason why hurricane Katrina became more powerful after passing over the Gulf of Mexico.  This links the strength of storms to global warming.

11. What has happened to Lake Chad over the years?

Lake Chad has dried up over the last 40 years or so. Gore’s hypothesis is that global warming redistributes precipitation so that this region of Africa has not received as much rain in recent decades. Additionally, he suggests that global warming dries up the soil via evaporation.

12. How much of the sun’s radiation gets reflected by ice?

Over 90% of radiation from the sun that strikes ice will be reflected. When the radiation hits the water near the glaciers however, 90% will be absorbed. Thus, when ice caps melt in a given area, there is an enormous increase in the amount of heat absorbed.  This means the melting of the ice caps is self-fueling

13. What redistributes energy from the equator to the north and south poles?

Ocean currents and wind currents redistribute energy in the form of heat to the North and South Pole. This means that a global average temperature increase will actually affect the North and South Pole more than at the equator. This compounds the global warming issue in these regions.

14. If the ice sheets of Western Antarctica were to melt, approximately how much would sea level
rise?

The sea level would rise by approximately 20ft if the ice sheets of Western Antarctica melted. This would cause flooding in the San Francisco Bay and Manhattan among other areas throughout the world. Also, Florida would flood up to Lake Okeechobee. Boston is only 19ft above sea level. Ice cap melting would cause a massive displacement of populations living in these regions.

15. List the three factors causing the collision between civilization and earth

1. Population: Unchecked population growth cannot be supported by finite natural resources.
2. Scientific and Technological Advancements: It is difficult to predict our impact on the environment when we are adjusting technological practices.
3. Way of Thinking: Since the change is gradual, we are less likely to pay serious attention to the issue of global warming.

16. Approximately, what percentages of global carbon dioxide emissions come from forest fires?

30% of annual global carbon dioxide emissions come from the burning of forests.

17. What country is the largest contributor of greenhouse gases into the atmosphere?

According to the video, we are by far the largest contributor of greenhouse gas emissions (per capita and overall).

18. Which country has the lowest government standards for gas mileage of automobiles?

The United States have the lowest government standards for gas milage.

19. Which two nations have not signed onto the Kyoto Protocol?

The United States and Australia have not ratified the Kyoto Protocol.

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