|Cutting Greenhouse Gases
Global warming correctly describes what was once called the Greenhouse Effect. It's a theory that says the Earth is getting warmer. The Earth is warmer in the last century but no one can say for certain whether it's due to human activity or just the normal Earth cycles. Broadly, this is all referred to as climate change.
Understand that the temperature of the Earth changes over centuries due to changes in the sun's distance and energy, as well as volcanic eruptions and meteor impacts that can cloud the atmosphere and block sunlight. Just as weather changes, so does climate. Over the course of centuries the Earth can get colder, warmer, wetter or drier. In the last century we've warmed about 1 degree, sea level has risen, and Arctic glaciers have melted. All of this has occurred while carbon dioxide levels have increased due to human activities. At first thought you might try to connect CO2 and the warming effects but it's not as simple as that. It is interesting to know that 2005 tied 1998 as the warmest year on record.
NASA scientists have that found cirrus clouds, formed by contrails from aircraft engine exhaust, are capable of increasing average surface temperatures enough to account for a warming trend in the United States that occurred between 1975 and 1994. Contrails form high in the atmosphere when the mixture of water vapor in the aircraft exhaust and the air condenses and freezes. Persisting contrails can spread into extensive cirrus clouds that tend to warm the Earth, because they reflect less sunlight than the amount of heat they trap. The balance between Earth's incoming sunlight and outgoing heat drives climate change.
In other recent research, NASA and Columbia University climate scientists shows that more than 25 percent of the increase in average global temperature between 1880 and 2002 may be due to soot contamination of snow and ice worldwide. Pure snow and ice can be blindingly bright, reflecting large amounts of incoming radiation back into space, whereas snow and ice that is contaminated with black carbon absorbs incoming solar radiation. More recently NASA has confirmed that the Antarctic is losing more ice than it gains from snowfall resulting in rising sea level.
Global warming, or the Greenhouse Effect, says that the atmosphere warms because we put gases and pollution into the air that trap heat. We do know that the average temperature of the Earth has warmed slightly in the last century but what's not known is how much of this is due human activities. Most scientists agree that what we put into the atmosphere can trap more heat and that countries would be wise to reduce emissions of these pollutants and gases.
What scientists disagree on is what happens after the Earth starts warming. It's possible that all of the natural processes will be able to counterbalance any warm-up or even reverse it. On the other hand, some computer models predict that a warm-up could go out of control. The problem is that we've never experienced exactly what we are trying to figure out. Only time will give the true answer.
So how do we measure global temperature? We use averages of temperature readings throughout the many nations. This is not a complete picture because two-thirds of the world is covered by water. Satellites now carry sensors that give us temperatures in remote locations.
If a global warm-up occurs, not all regions will get warmer. Some will get cloudier and wetter, while others cool down. Some regions may warm only at night while others get colder in one season and warmer in another.
There are many possibilities and combinations and the only certainty is that the Earth's temperature will change with time. You can learn more at the EPA Global Warming Site or the Intergovernmental Panel on Climate Change or The Pew Center on Global Climate Change or the US Science Climate Change Program.
To combat global warming, many countries (155 and counting) have come together to sign the Kyoto Protocol. Under this international agreement, each country involved has agreed to reduce the amount of greenhouse gases it produces. But not all countries emit similar amounts, and what we do as everyday citizens affects climate, too.
Although the United States signed the Kyoto Protocol, the treaty has not been ratified by the U.S. Senate. In July 1999, the United States Senate voted 95-0 to pass a resolution co-sponsored by Sen. Byrd (D-W.Va.) and Sen. Hagel (R-Neb.), which stated the Senate would not ratify the Protocol unless rapidly developing countries such as China were included in its requirements to reduce greenhouse gases. The Clinton Administration announced it would not send the treaty to the Senate for ratification and President Bush has not sent it either.
Your task, Part 1: Answer questions 1-6 first. What is global warming?
Why has the Earth’s temperature changed?
What are contrails?
Why has there been a 25% increase in global temperature between 1880 & 2002?
What is global warming and how does it happen?
How do we measure global temperatures?
Who produces the most greenhouse gas?
Now, look at the following chart of greenhouse gases and make a bar graph that compares the greenhouse gases emissions for 1998 for all countries. Then, locate each of those countries on a world map. Highlight the countries using a highlighter. Finally, answer these questions:
Who produces the least greenhouse gas?
Why do they produce the most and least—is their country industrialized and/or large?
What is the smallest country involved and its emissions?
What is the largest country involved and its emissions?
Are you responsible for producing greenhouse gases? How? Explain.
What are some ways that each of us could help reduce greenhouse gases? Your ideas will be used to draw up a Greenhouse Treaty for our classroom.
Your task, Part 2: Read about El Nino and La Nina and answer the questions following them.
El Nino is Spanish for "The Child." It's the name given to a major warming of the water in the eastern Pacific Ocean along the equator, off the coast of South America. The warming reaches a peak around Christmas and causes more wet weather in that region along with a shift in global weather patterns. El Nino is a normal part of the Earth's weather. El Nino does not happen every year but when it does happen, Pacific Ocean temperatures can be anywhere from two to ten degrees above average. While this may not seem like much, a major warming of Pacific Ocean water can cause changes worldwide. In some places the weather turns cooler, or wetter, while other places can become warmer, or drier. Many locations do not see any changes but for every region that experiences stormier weather, there's another region that sees calmer weather.
Meteorologists and Climatologists are still learning what types of weather shifts we can expect with an El Nino. What causes it is not totally known. We can't yet predict an El Nino but we have a sense of what it does.
La Nina is the opposite of El Nino. La Nina is when the Pacific Ocean water is much cooler than average. This also has an influence on worldwide weather. A strong La Nina means that the Atlantic hurricane season may be more active. Here's the latest status on La Nina and how it may influence our hurricane season.
You can find the current El Nino/La Nina advisory at the Climate Prediction Center, and more information on El Nino at Center for Ocean-Atmospheric Prediction Studies Library at Florida State University.
Both El Nino and La Nina mean weather patterns will shift. Neither one is all bad or all good. It depends on where on Earth you live and what season you are concerned about.
NOAA SAYS LA NIÑA HERE AS PREDICTED
Expect Northwest Storminess and More Drought in South/Southwest
Feb. 2, 2006 — The NOAA Climate Prediction Center announced today the official return of La Niña. Agency forecasters predicted La Niña was forming nearly three weeks ago. Oceanic sea surface temperatures have met the operational definition of La Niña for the November through January period. La Niña is the periodic cooling of ocean waters in the east-central equatorial Pacific, which can impact the typical alignment of weather patterns around the globe. NOAA predicts this La Niña event will likely remain into late spring, and possibly into summer.
("In mid-January the atmosphere over the eastern North Pacific and western U.S. began to exhibit typical La Niña characteristics in response to the cooling in the tropical central Pacific Ocean," said Vice Admiral Conrad C. Lautenbacher, undersecretary of commerce for oceans and atmosphere and NOAA administrator. "This pattern will favor continued drought in parts of the South and Southwest from Arizona to Arkansas and Louisiana, and above normal precipitation in the Northwest and the Tennessee Valley area." Periodic precipitation in the drought areas and dryness in the stormy areas also are typical within the larger scale climate pattern described above.
Internationally, La Niña impacts during the Northern Hemisphere winter typically include enhanced rainfall across Indonesia and northern Australia, as well as in the Amazon Basin and in southeastern Africa and below-average rainfall across the eastern half of the equatorial Pacific and eastern equatorial Africa.
Typically, La Niña events favor increased Atlantic hurricane activity, however, Jim Laver, director of the NOAA Climate Prediction Center says, "It is too early to say with confidence what effects this La Niña event will have on the 2006 hurricane season."
La Niña events are operationally defined using the Oceanic Niño Index (ONI), which is the three-month running-mean values of sea surface temperature departures from average in the Niño 3.4 region of the central Pacific (bounded by 5N-5S, 120-170W). NOAA defines La Niña as the condition whereby the ONI is less than or equal to -0.5 degrees C. This definition was adopted by the U.S. and 25 other countries in North and Central America and the Caribbean in April 2005.
La Niña events recur approximately every three to five years. The last La Niña occurred in 2000-2001 and was a relatively weak event compared to the 1998-2000 event.
What is El Nino?
When and where does it occur?
How often does El Nino occur? What happens when it does occur?
What is La Nina?
Where does it occur?
What influence does it have on our weather?
How often does La Nina occur?
Answers to La Nina and El Nino questions:
1. Why has the Earth’s temperature changed?
No simple answer, but includes natural change due to distance from sun and sun’s energy; volcanic eruptions and meteor impacts clouding the atmosphere and blocking sun; Earth’s natural change in temperature; increased CO2.
2. What are contrails?
Cirrus clouds formed by the exhaust of jet engines.
3. Why has there been a 25% increase in global temperature between 1880 and 2002?
Soot contamination of snow and ice worldwide, which makes ice absorb radiation rather than reflect it.
4. What is global warming and how does it happen? Gradual warming of Earth; see #1
5. How do we measure global temperatures? We use averages of temperature readings taken throughout many nations.
6. Who produces the most greenhouse gas—using information given? US
What is El Nino? It’s the name given to a major warming of the water in the eastern Pacific Ocean along the equator, off the coast of South America.
9. When and where does it occur? The warming reaches a peak around Christmas and causes more wet weather in that region along with a a shift in global weather patterns.
10. How often does El Nino occur? What happens when it does occur? It is a normal part of Earth’s weather and does not happen every year. When it does happen Pacific Ocean temperatures can be from 2 to 10 degrees above average, causing cooler, wetter, warmer, or drier weather in places around the world.
11. What is La Nina? Opposite of El Nino. Pacific is much cooler than average. Influences global weather and could mean a more active Atlantic hurricane season.
12. Where does it occur? Atlantic Ocean
13. What influence does it have on our weather? More hurricanes; more rain in Indonesia and northern Australia, Amazon Basin and southeastern Africa; below average rainfall for eastern half of equatorial Pacific and eastern equatorial Africa
14. How often does La Nina occur? Every 3 to 5 years