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Their data show that an increase of one degree Celsius makes the Earth armed now than it has been for at least a thousand years. Out of the 20 warmest years on record, 1 9 have occurred since 1980. The three hottest years ever observed have all occurred in the last ten years, even. Earth should be in cool-down-period But it is not only about how much the Earth is warming, it is also about how fast it is warming. There have always been natural climate changes – Ice Ages and the warm intermediate times between them – but those evolved over periods of 50,000 to 100. 00 years. Http://knowledge. Lillian. Com/en/ globalizes/climate_change/global_warming_basics/ What Is The Greenhouse Effect? Seen from space, our atmosphere is but a tiny layer of gas around a huge bulky planet. But it is this gaseous outer ring and its misleadingly called greenhouse effect that makes life on Earth possible – and that could destroy life as we know it. The sun is the Earth’s primary energy source, a burning star so hot that we can feel its heat from over 1 50 million kilometers away.
Its rays enter our atmosphere and shower upon on our planet. About one third of this solar energy is reflected back into the universe by shimmering glaciers, water and other bright surfaces. Two thirds, however, are absorbed by the Earth, thus warming land, oceans, and atmosphere. Much of this heat radiates back out into space, but some of it is stored in the atmosphere. This process is called the greenhouse effect. Without it, the Earth’s average temperature would be a chilling -18 degrees Celsius, even despite the sun’s constant energy supply.
In a world like this, life on Earth would probably have never emerged from the sea. Thanks to the greenhouse effect, however, heat emitted from the Earth is trapped in the atmosphere, providing us with a comfortable average temperature of 14 degrees. The switch from carbon dioxide to oxygen Nitrogen, oxygen, and argon make up 98 percent of the Earth’s atmosphere. But they do not absorb significant amounts of infrared radiation, and thus do not contribute to the greenhouse effect.
It is the more exotic components like water vapor, carbon dioxide, ozone, methane, nitrous oxide, and chlorofluorocarbons that absorb heat and thus increase atmospheric temperatures. Studies indicate that until some 2. 7 billion years ago, there was so much carbon dioxide (CO) and methane in our atmosphere that average temperatures on Earth were as high as 70 degrees. But bacteria and plants slowly turned CO into oxygen and the concentration of CO in our current atmosphere dropped to just about 0. 38 percent or 383 parts per million (pump), a unit of measurement used for very low concentrations of gases that has become a kind of currency in climate change debates. Minuscule changes -?? global impact But while we are still far from seeing major concentrations of CO in our atmosphere, slight changes already alter the way our celestial heating system works. Measurements Of carbon dioxide amounts from Manna Lola Observatory in Hawaii show that CO has increased from about 313 pump in 960 to about 375 pump in 2005.
That means for every million particles in our atmosphere, there are now 62 CO-particles more than in 1960. Even if this does not seem like much, scientists say this increase – most probably caused by human activities – is mainly responsible for rising global temperatures throughout the last decades. Related Articles * Carbon Dioxide – Endless Warming * India Climate Change Profile Part 6: Receding Glaciers Spell Disaster Even if the term “greenhouse effect’ is somewhat of a misnomer, it still might be a useful handle from which the public can grasp an otherwise intricate trial process.
Most people can relate to how hot and stuffy a greenhouse can get. Now that the Earth has started to heat up, we realize that our own global greenhouse has no window that we can open to catch some fresh air. Http://knowledge. Lillian. Com/en/globalizes/climate_change/ global_warming_basics/global_warming_greenhouse_effect. HTML What Will The Climate Be Like in 2100? Stanford University climatologist Stephen Schneider discusses what we know and don’t know about the future of the Earth’s climate, and whether it is worth spending trillions of dollars to fight climate change.
What will the Earth’s climate be like at the end of this century? What’s the old joke? Prediction is hard, especially about the future. What do you have to do to predict the climate of 21 00? Well, you have to know how much CO, methane, nitrous oxide, aerosols – that’s dust and smoke – are going to be there, because that changes what we call the forcing – the pressures on the climate system – to be warmer or colder. We know it’s going to be warmer. That’s virtually certain. But you don’t know what those are going to be on the basis of any history.
There’s never been a time before when there was six to ten billion people on he Earth, when they’re demanding dramatic increases in their standards of living, and when they’re using the cheapest available technology – usually coal and oil burning big cars – to get there. So, before you can forecast how warm it will be in 2100 – and whether it’s worth a trillion-dollar investment not to have that outcome -you’ve got to know a bunch of social factors. Http:// knowledge. Lillian. Mom/en/globalizes/climate_change/ global_warm Greenhouse Gases: Lifesavers and Lifesavers In what seems like nature’s brutal irony, the gases that make life on Earth possible now threaten our very existence. Read our greenhouse gas profiles ND find out why CO, methane, and nitrous oxide might become benevolent climate killers -?? and how we can react. Greenhouse gases heat up our planet. They are part of Earth ;s atmosphere and trap warmth emitted by the sun, thus heating Earth. It is this process – the greenhouse effect – that makes life on the planet possible.
Natural greenhouse gases like carbon dioxide, methane, and nitrous oxide have always been in the atmosphere. Without them, the world’s average surface temperature would be a chilly -18 degrees Celsius. Thanks to the greenhouse effect, however, we enjoy an average temperature of 14 degrees. Throughout Earth’s history, temperatures have varied greatly, mostly depending on the concentration of greenhouses gases in the atmosphere. All signs now suggest that a major temperature change is happening again, but this time humanity is the cause.
Read our gas profiles and learn more about the causes of climate change and how we can reduce them. Http:// global_warming_basics/greenhouse_gas_profiles_all. HTML What Human Activities Contribute to Climate Change? The burning of coal, Oil, and natural gas, as well as deforestation and various agricultural and industrial practices, are altering the composition of the atmosphere and contributing to climate change. These human activities have led to increased atmospheric concentrations of a number of greenhouse gases, including carbon dioxide, methane, nitrous oxide, chlorofluorocarbons, and ozone in the lower part of the atmosphere.
The relative importance of these gases is shown in Figure 4. 1. Figure 4. 1 Relative importance of the various greenhouse gases and small particles currently in the atmosphere. Bars extending above the horizontal line indicate a warming effect. Bars extending below the horizontal line indicate a cooling effect. The impacts of troposphere ozone, stratospheric zone, and particles are quite uncertain. The range of possible effects for these gases is indicated by the red bar; I. E. , the effect is in the range of one end of the red bar to the other.
Carbon dioxide is produced when coal, oil, and natural gas (fossil fuels) are burned to produce energy used for transportation, manufacturing, heating, cooling, electricity generation, and other applications. The use of fossil fuel currently accounts for 80 to 85% of the carbon dioxide being added to the atmosphere. Land use changes, e. G. , clearing land for logging, ranching and agriculture, also lead to carbon oxide emissions. Vegetation contains carbon that is released as carbon dioxide when the vegetation decays or burns.
Normally, lost vegetation would be replaced by Rexroth with little or no net emission of carbon dioxide. However, over the past several hundred years, deforestation and other land use changes in many countries have contributed substantially to atmospheric carbon dioxide increases. Although deforestation is still occurring in some parts of the northern hemisphere, on the whole, re-growth of vegetation in the north appears to be taking some carbon dioxide out of the atmosphere. Most of the net carbon dioxide emissions from deforestation are currently occurring in tropical regions.
Land use changes are responsible for 15 to 20% of current carbon dioxide emissions. I Figure 4. 2 Carbon dioxide emissions from the burning of coal, oil, and natural gas are shown for the period 1860 to 1992 for three groups of countries. Methane (natural gas) is the second most important of the greenhouse gases resulting from human activities. It is produced by rice cultivation, cattle and sheep ranching, and by decaying material in landfills. Methane is also emitted during coal mining and oil drilling, and by leaky gas pipelines.
Human activities have increased the concentration of methane in the atmosphere by about 145% above what would be present naturally. Nitrous oxide is produced by various agricultural and industrial practices. Human activities have increased the concentration of nitrous oxide in the atmosphere by about 15% above what would be present naturally. Chlorofluorocarbons (CIFS) have been used in refrigeration, air conditioning, and as solvents. However, the production of these gases is being eliminated under existing international agreements because they deplete the stratospheric ozone layer.
Other fluorocarbons that are also greenhouse gases are being used as substitutes for CIFS in some applications, for example in refrigeration and air conditioning. Although currently very small, their contributions to climate change are expected to rise. Ozone in the troposphere, that is, in the lower part of the atmosphere, is another important greenhouse gas resulting from industrial activities. It is created naturally and also by reactions in the atmosphere involving gases resulting from human activities, including nitrogen oxides from motor vehicles and power plants.
Based on current tat, troposphere ozone is an important contributor to the enhanced greenhouse effect. However, in part because ozone is also produced naturally, and because of its relatively short atmospheric lifetime, the magnitude of this contribution is uncertain. Contrary to popular perception, the Antarctic ozone hole does not cause global warming. Instead, the global depletion of stratospheric ozone caused by CIFS and other gases has resulted in a small cooling effect as shown in Figure 4. 1. Human activities, such as the burning of fossil fuels and changes in land use, have increased he abundance of small particles in the atmosphere.