The Effects of Global Greenhouse Warming
By: oneclickdoctor
If the greenhouse effect has again been currently in the news, it is probably because it is once again being blamed for causing global warming. Stronger hurricanes, periods of extreme weather, heat waves, the frequency of the El Nino phenomenon, these are all attributed to global warming. But how does the greenhouse effect figure in all these?
What is the greenhouse effect?
The greenhouse effect is the ability of our planet’s atmosphere to trap and contain heat. This heat is sourced from the sun and is reflected back towards the atmosphere. Certain gases are responsible for this entrapment and they include carbon dioxide, nitrous oxide, methane, fluorinated compounds and water vapor. Other man-made chemicals are also capable of retaining heat within the atmosphere.
In itself, the greenhouse effect is not essentially evil. In fact, it is this very phenomenon that has produced life on earth as we know it. Think of the greenhouse effect as a natural thermal blanketing for our planet, maintaining a surface temperature that is just right to encourage organisms to grow and survive. Without this blanketing, the earth’s climate would be too cold – about 59F lower than the average – for our planet to be able to sustain life successfully.
How does the greenhouse effect contribute to global warming?
For more than 4 billion years, the greenhouse effect has kept our planet’s temperature at a friendly level. Gases found in the atmosphere act to trap heat and keep our planet insulated, able to sustain itself. Problems only began to arise when scientists noticed that certain practices and human activities contribute to the modification of this process.
When the Industrial Revolution began, we also devised many ways of using fossil fuel for oil, coal and gas. The only way to utilize these fuels was by burning. As industrialization continued to expand, so did the practice of fossil fuel burning, thereby releasing gases into the atmosphere. The only problem was that these gases had nowhere else to go and have continued to build up over the years.
By building up, they cause the atmosphere to become more efficient in trapping heat, causing climates to turn warmer. This unnatural or man-made result is referred to as global warming.
How global warming affects us
We have been experiencing the effects of global warming for the past years and most of these are felt through changes in the climate. However, it’s important to note that climate change is brought about by other factors and not just as an indirect result of the greenhouse effect. Some of these factors include changes in the circulation of the oceans, changes in our planet’s orbit and even changes in the intensity of the sun itself.
Global warming involves increase in the average temperature of the earth’s atmosphere near its surface. While global warming is nothing new to our planet (it has occurred over long periods in the earth’s 4.5-billion-year history alternating with ice ages), it is only now when its drastic changes on a global scale has dire consequences not just for human kind but also to the millions of species that depend upon the earth for sustenance.
A famous example of the effect of global warming is the increase in sea level, brought about by the melting of glaciers. This is a problem not readily seen nor felt in countries or regions that lie on higher ground, but for many areas, this could mean land (and subsistence opportunities) lost to sea. A 0.3-meter increase in sea level for example, can eat up about 15 meters of beach.
As temperatures rise, countries that have agricultural practices firmly dependent on the regularity of glacier-melting will suffer greatly. For many regions in the world, the melting of snowpacks from the mountains means water for plant irrigation and electricity. If the melting occurs at a bad time, the planting and harvesting of crops will be significantly disrupted, causing problems in the economy on a local and national level.
With global warming, abrupt weather changes may also be experienced, such as heat waves that last longer and occur with more frequency, stronger storms and hurricanes and even changes in the behavior of the winds. Warmer climate will also contribute to the displacement of plants and animals, as those who depend upon lower temperature regions to survive will need to move to higher elevations and latitudes. For plants and animals who cannot adapt, it could mean extinction.
Healthwise, diseases that right now are currently limited by the location and living habits of their carriers have the possibility of invading areas that didn’t have a problem with them before. An example of this is malaria, along with other diseases caused by mosquitoes.
Mosquitoes thrive in tropical settings and as more and more regions become warmer, mosquitoes will expand their range. They will now be able to go to areas that they usually do not inhabit because of the temperature. This exposes the formerly unexposed population to the health risks caused by mosquito-borne diseases that also include dengue and elephantiasis.
Facing global warming
The balance of life and competition among species may also be disrupted, in more ways than are currently foreseen. In fact, with global warming, certain lifestyles and animal behavior that we have enjoyed so far may also disappear, unless we do something to try to correct and arrest the problem.
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March 23 2009 | The Transition Companies | Comments Off
By Lois Grant-Holland
The earth is wrapped in a thin, loose shell of gases – which we call the atmosphere. The mix of gases that make up the atmosphere has changed greatly over the eons.
A Flemish alchemist and physician named Johann Baptista van Helmont was the first man to discover that the air we breathe is not one single substance but a mixture of substances. In a manuscript published after his death in 1644, he argued, based on his experiments, that an invisible “spirit” curled from every one of the bubbling flasks in his alchemical laboratory, and from each of the red coals in his furnaces. “I call this Spirit, unknown hitherto, by the new name of Gas,” he wrote – coining the word from the Flemish pronunciation of the Greek word “chaos.” One of the gases that he discovered was carbon dioxide, a gas that is now creating chaos on a global level.
Since van Helmont’s discovery, we have come to realize, through scientific experimentation and persistent measurements, that carbon dioxide is almost everywhere. By the 1950s, Charles Keeling, working under the auspices of the California Institute of Technology, began extensive tracking of carbon dioxide levels on the planet. He recognized a pattern that had eluded others: the carbon dioxide concentration always dropped as the sun rose in the sky, and then in- creased as the sun went down. The count stayed high all night, bottomed out in the afternoon, and began climbing again after sundown.
The life cycle was becoming more and more obvious to the scientific community: every day, as the sun rises, every green thing on the planet – from skunk cabbage to club moss – begins inhaling carbon dioxide, for use in photosynthesis. As the plants inhale, the amount of gas in the air begins to drop.
Photosynthesis is, literally, “building with light.” The building process takes place inside plant cells within organelles call chloroplasts. Inside each choloroplast, plants break apart molecules of carbon dioxide into carbon and oxygen. They also break water molecules into hydrogen and oxygen. Then they put most of these atoms back together in new combinations to build simple sugars like glucose, throwing out some of the oxygen as “trash.” The process requires steady supplies of sunlight for energy, and steady supplies of carbon dioxide and water for raw materials.
By afternoon, plants have taken a good deal of carbon dioxide out of the atmosphere. At the same time, however, the plants are busily eating the sugars they have made for themselves. This is the metabolic process of respiration. Respiration means literally “to breathe back, to blow back;” it is a form of combustion, a very slow burn which consumes oxygen and produces carbon dioxide.
Photosynthesis and respiration are two of the most fundamental processes of life on Earth, and they run in opposite directions. Photosynthesis takes in carbon dioxide and releases oxygen; respiration takes in oxygen and releases carbon di- oxide. The two processes also run on different timetables: photosynthesis works a day shift, because the process requires sunlight and most plants take in carbon dioxide only when the sun shines. The gas enters the plant through a myriad of microscopic pores, stomata, on the underside of each green leaf. These little doors open at sunrise and close at sundown on every plant on the planet.
Respiration, on the other hand, works both a day shift and a night shift. At four o’clock in the morning – while the stomata are closed and green leaves are taking in virtually no carbon dioxide – the leaves are still respiring, blowing back carbon dioxide to the air. At the close of most twenty-four hour periods, most plants have “borrowed from and returned to” the atmosphere about the same amount of carbon dioxide.
This “breathing cycle” is apparent throughout the plant life on the planet: plants and trees breathe once a day. (Animals, including people, aren’t a natural part of this cycle. They have no cholorplasts, so they get their energy and their raw materials by eating plants, and by eating the animals that have eaten plants, and by inhaling the oxygen released by plants.)
So?
So this natural breathing cycle of the earth’s plant life is a major factor in one of the major ecological problems facing the planet: the greenhouse effect.
It is the atmosphere that keeps us warm; outer space is a very cold place, and it is the layers of gases that wrap the planet that protect us from freezing. In this sense, the Earth’s gases are like the glass walls of a greenhouse.
The gases which have the highest volume in the atmosphere are not the gases that are having the most powerful greenhouse effect. Nitrogen and oxygen – which constitute 99% of the atmosphere – have almost no greenhouse effect at all. The three gases that DO have a major effect are water vapor, carbon dioxide, and ozone.
Like nitrogen and oxygen, these three gases are almost perfectly transparent to the sunlight that streams to the Earth from the Sun. However, water vapor, carbon dioxide, and ozone are partially opaque to the infrared heat radiation that rises from the sun-baked ground.
When this infrared radiation strikes the water vapor, carbon dioxide or ozone molecules, the molecules give off energy in the form of more infrared rays. In a sense, every carbon dioxide molecule in the atmosphere is like a dark star shining in all directions – up, down, and sideways. In this way, invisible rays of energy get passed back and forth many times between the atmosphere and the layers of the planet before the energy finally migrates to the top of the atmosphere and escapes into the vacuum of outer space.
That is the greenhouse effect in a nutshell: the dark rays bounce around inside the atmosphere many times before they finally manage to leak out into space. Water vapor, carbon dioxide, and ozone – rare though they are – turn the world’s air into a giant heat trap. And for billions of years, life on Earth has been dependent on this peculiar property of these three gases (and a few others that are even rarer) to keep the planet livable.
The carbon dioxide level in the atmosphere is a vital ingredient in the natural life cycle of the planet and the life forms it contains; if the amount of carbon dioxide varies by too much, the results on the planet could be disastrous. A minute drop, the scientists discovered, could chill the entire planet, and may have been the force behind the last Ice Age.
But what are the effects of a rise in the carbon dioxide count? As early as the 1890s, scientists predicted that this change could very well heat the planet to heights outside all human experience. It became increasing clear that the problem lay not in a possible drop in the carbon dioxide levels, but in a rise – based on new technology that introduced tons of carbon dioxide into the atmosphere – that would change the atmosphere itself. Any change in the atmosphere would, of necessity, change the life cycles themselves.
Beyond the daily photosynthesis/respiration cycle is a larger cycle. To understand it, we need to enlarge our vision to include the whole pageantry of the seasons, the annual passage of foliage from green to red and yellow to brown and black, in terms of invisible effects. Plants take up carbon dioxide mainly in the spring and summer, their green and busy season. They drop their leaves in the fall. The leaves wither and decay, and the carbon that the plants had borrowed from the air that summer returns to the air.
Here again, photosynthesis and respiration march to different drummers. Photosynthesis is mostly a thing of summer. It begins in April, peaks in June, and drops near zero in October, when there is too little sunlight. In other words, it runs hard during the light part of the year and all but quits during the dark part of the year.
Respiration peaks in June, too, but unlike photosynthesis it never stops (except where the ground is frozen) – it keeps on going, throughout the winter and all year round. The life forms that decompose the fallen leaves include fungi, bacteria, worms, termites, slugs, and leaf molds. They compete to eat the dead leaves, to rot the fallen branches, and together they return most of life’s borrowed carbon to the air.
Every year, when green things inhale carbon to put out buds, shoots, leaves and stems, the biosphere inhales. When the leaves fall and molder on the ground, the biosphere exhales. In the most beautiful, regular and global cycles in nature, the planet itself takes one breath a year. It is that breathing pattern that has been put at risk by the rise in carbon dioxide levels.
The atmospheric counts for the years since the 1950s show a definitive pattern: each fall, there is a rise in the record. Each summer, there is a dip in the record. Each winter, the high is higher than it was the winter before. The impact is clear.
The Transition Companies Breath of Life
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March 05 2009 | The Transition Companies Breath of Life | Comments Off
The Greenhouse Effect – What Is It?
By: Kenneth Scott
There has been much discussion, both among experts and lay people, about the greenhouse effect. The greenhouse effect is a term that refers to changes in the Earths atmospheric composition, which have been related to the warming of our planet. There is a growing amount of evidence that human activities, particularly those relating to the burning of fossil fuels like oil and coal, are major contributors to the greenhouse effect. The predicted consequences for the planet as a result of the greenhouse effect are extremely serious. They include major changes in the climate that will have an impact on food production and rising sea levels, which will put many coastal and other low-lying communities under water.
Additional information that we have learned about the planet Venus provide a frightening example of the greenhouse effect. Venus has a very dense atmosphere made up of gases. The planet has what has been described as a runaway greenhouse effect. It has surface temperature of about 800 degrees Fahrenheit.
Experts generally point to gases like carbon dioxide as the main contributors to the greenhouse effect. Carbon dioxide, which is a gas that is exhaled by everyone, can absorb infrared radiation. This type of radiation is heat that is radiating away from a warm object. During the day, the Earth is warmed by sunlight, and at night, the Earth cools off by radiating the heat back into space in the form of infrared radiation. Carbon dioxide, and other gases to some extent, absorb this radiation and limit its exit into space. Therefore, the natural cooling mechanism is thwarted.
While it may seem that eliminating the greenhouse effect would be the best strategy, this is not what we want to do. Water vapor represents another element in the heat-absorbing process. There is a great amount of water vapor in the atmosphere at all times. This is why we experience rain. We need the water vapor in the atmosphere to keep the Earth at its normal, comfortable temperature.
The Transition Companies and What Is It?
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January 14 2009 | The Transition Companies and What Is It? | Comments Off