Atmosphere and Climate Issues. Global Warming, The Ozone Hole, and Air Pollution. The Atmosphere. The layers of the atmosphere are divided based on the temperature difference at each level. www.ds9.ssl.berkeley.edu. The Atmosphere.
Global Warming, The Ozone Hole, and Air Pollution
The layers of the atmosphere are divided based on the temperature difference at each level.
Note that the troposphere contains 90% of the gases in the atmosphere and is where weather occurs.
The troposphere also has the highest air pressure – it’s like being at the bottom of an ocean of air!
This is the layer that we live in!
Latitude is the most important factor that determines climate. In general, the closer to either pole a location is, the cooler it will be. This is due to the diffusion of the sun’s rays at higher latitudes. The equatorial regions receive the most intense solar radiation and are generally always warm.
Global surface winds determine where different types of air masses are moved, thus determining the climate of an area.
Deserts are usually found around 30 degrees North or South latitude. Warm, humid air rises at the equator, cools, drops its precipitation, and then the cooled dry air sinks at these latitudes, creating deserts.
Currents balance the temperature of Earth’s oceans. They also affect the climate of large areas of land: Cold currents cool western coastlines whereas warm currents warm eastern coastlines.
Mt. Kilimanjaro is only 3 degrees from the equator but at over 19,000 ft in elevation, its summit is always covered in snow.
The side of a mountain range a location is on will determine whether it gets rain or not – depending on which way the prevailing winds blow.
Differences in seasons are caused by the tilt of the Earth away from the sun during winter and towards the sun during summer.
What is the greenhouse effect? It is heat from the sun being trapped by the gases in our atmosphere.
What are greenhouse gases? They are gases in the atmosphere that trap and radiate heat from the sun.
Notice the solar radiation that is reflected back to space from the tops of the clouds and the heat that is reflected back to Earth’s surface by the bottom of the clouds.
Water vapor’s role in the greenhouse effect (accounting for 70% of the affect) is not completely understood and is difficult to model in computer simulations on global warming.
Carbon dioxide is released into the atmosphere by respiration, decay, and burning of fossil fuels. It is absorbed or stored by such carbon sinks as untapped fossil fuels, oceans, and forests.
The biggest threat to the rainforest is man. The ever-expanding human population is exerting tremendous pressure on the resources and the space of the rainforest. This is a hillside which has been cleared of its trees through the traditional "slash-and-burn" technique. You can already see erosion washing gullies on either side of this hill. As forests like this are slashed and burned, carbon dioxide is released and important carbon sinks are lost.
“Bessy the Science Cow
Bessy and her cow friends are one of the world's greatest methane emitters. Cows exhale methane, which is a byproduct of the digestion of their grassy diet.”
To review ….
What are some anthropogenic (human-related) sources of the aforementioned greenhouse gases?
What are some natural sources of greenhouse gases?
cellular respiration (living things breathing) – give off carbon dioxide
decomposition in wetlands & rice patties, livestock – give off methane
In 1958, the geophysicist Charles keeling began taking measurements of CO2 in the atmosphere from atop Mauna Loa in Hawaii.
He found that the amount of CO2 in the atmosphere increased. (From 314 ppm in 1958 to 358 ppm in 1994 )The Carbon Dioxide Connection
The major source of CO2 (besides just exhaling!) is the burning of fossil fuels – which explains why global warming activists call for a reduction of “emissions.”
Remember, a correlation does not prove a cause and effect. Some scientists have pointed out that carbon dioxide levels rise in response to natural warming.
“The large, full-colour “hockey-stick” was the key graph in the UN’s 2001 report, and the only one to appear six times. The Canadian Government copied it to every household. Four years passed before a leading scientific journal would publish the truth about the graph. Did the UN or the Canadian government apologise? Of course not. The UN still uses the graph in its publications.” http://globalwarming.worldwidewarning.net/
This is the data that Michael Mann et al. conveniently - or deceptively – pick your adverb – left out of their “hockey stick” graph. Note that the Medieval Warming is a bit warmer than today – way before the Industrial Revolution!
Mann’s data was faulty – ignoring the fertilizing effects of carbon dioxide on bristlecone pine trees. His study contradicted what is known about the Medieval Warming and the Little Ice Age – from hundreds of historical sources and scientific papers. Being politically correct, Mann was named an IPCC lead author and an editor of The Journal of Climate!
Historically, two circumstances have caused global climate change:
- An increase in the solar output of the sun (warming the Earth)
-Volcanic eruptions (cooling the Earth)
It was largely caused by the eruption of Tambora, Indonesia, in April 1815, in one of the largest known eruptions of the past few millennia.
The aerosol veil caused Northern Hemisphere cooling of up to 1 degree Celsius, and considerably more locally, with effects lasting until the end of 1816 and extending to both hemispheres.
Snow fell in New England in June.
Abnormally cool temperatures in Europe led to widespread famine and misery, although the connection to volcanic aerosols was not realized at the time.
Image of the volcano is from the NASA Space Shuttle, showing the 7 kilometre-wide caldera depression formed in 1815. (Image: NASA.) ”
TamboraGlobal Cooling – The Eruption of Tambora
Tambora Volcano, Indonesia
The Little Ice Age occurred between 1300 AD to 1850 AD. During this time …
*There were reduced harvests and starvation.
*Diseases from overcrowding, malnutrition, and cold claimed more lives.
It’s an increase in the
temperature of Earth’s
Here’s what we know:
The Earth is getting warmer. (by about 1 degree C during the past 150 years)
We are currently in a warming period.
Sea level has risen by about 10 – 25 cm (about 7 inches) in the past 100 years.
Note that the Antarctic Peninsula is a small fraction (3%!) of Antarctica – but one of the most studied by scientists.
“In 1995 the northern part of the Larsen ice shelf(known as Larsen A) collapsed – a process observed by Envisat’s predecessor spacecraft ERS.
On 18 March 2002 another part known as Larsen B [collapsed], as captured by ASAR.
During this most recent collapse a 200-metre-thick shelf with an area of 3,300 km2, equivalent in size to more than a third of the island of Corsica or the whole of Luxembourg, was lost.” Credits: H. Rott
What’s a polar bear to do?
Computer models like the one run by Oxford scientist Myles Allen have shown that in the next 50 years, global temperatures could rise 3 – 4 degrees F.
This increase will surpass the critical level of 2 degrees F – which will have an impact on global climate. (If it happens!)
If this happens…
… there will be an increase in quantity and intensity of severe weather events such as hurricanes (warmer oceans).
… there will be changes in rainfall patterns (changing ocean currents)
… there will be severe flooding or droughts (changing rainfall patterns) This could cause the agricultural area of N. America to shift northward.
… there will be a rise in sea level (melting glacial ice) – flooding coastal areas.
… we will have a nice warm climate! (Bring out the beach chairs!)
This depends on the cause of warming! If it is due to carbon dioxide emissions, then reducing our emissions is the way to do it! (That is the mantra of the politically correct.) How?
1. Reduce our use of fossil fuels by…
conserving energy and searching for
alternative sources of energy.
2. Plant trees to increase the “carbon
3. Save our forests.
It is agreement on global warming reached by the UN Conference on Climate Change in Kyoto Japan in 1997.
The major industrial nations (163 as of April ’06) pledged to reduce their emissions of greenhouse gases between 2008 and 2012.
Why hasn’t the United States ratified the Kyoto Protocol?
- It would be very expensive to carry out (about $150 -$400 billion/ year)
- Our government wants more information on the causes of global warming.
- Our government isn’t convinced that the current warming is human-induced. (Faulty hockey stick graphs don’t do much to inspire confidence in the IPCC findings!)
The chemical formula for ozone is O3
The ozone layer is found in the stratosphere.
It absorbs ultraviolet radiation from the sun.
The ozone layer is important because…
Man-made chemicals called CFCs (chlorofluorocarbons) react with ozone and break it apart.
The part of the CFC molecule that reacts with the ozone molecule is the chlorine atom.
CFCs are used as refrigerants, coolants, propellants in aerosol cans, and styrofoam.
Scientist Susan Soloman of NOAA hypothesized that these CFC/ozone interactions were occurring in polar stratospheric clouds.
This diagram illustrates what a “hole” in the ozone might look like.
The ozone “hole” is really a thinning.
“The hole in the ozone layer above Antarctica is seen in a series of satellite images over a 21-year time span.
The hole may actually close within 50 years as the level of destructive ozone-depleting CFCs in the atmosphere is now declining, one of the world's leading atmospheric scientist Paul Fraser from the Australian government's Commonwealth Scientific and Industrial Research Organisation (CSIRO) said on Tuesday.
Fraser said he had measured a decline in ozone-destroying gases since 2000. — Reuters photo”
CFCs were banned in the late 1980’s in industrialized nations. They are still in use in some places in the world.(And it doesn’t help that the 2 billion plus people in China and India want air-conditioning, too!)
“Under the 1987 Montreal Protocol, developing countries committed themselves to halving consumption and production of the CFCs by 2005 and to achieving an 85 percent cut by 2007.”
Not actual scientists