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<<ನೀವು ಪರಿಚಯಿಸಿದ ತಲ್ಲಣ ಪದದಿಂದ ನೆನಪಾದ ಕನಕದಾಸರ ಪದ್ಯದ ಮೊದಲ ಸಾಲು ಹೀಗಿದೆ: "ತಲ್ಲಣಿಸದಿರು ಕಂಡ್ಯ ತಾಳು ಮನವೇ....">> ಹೌದು ಇ೦ಥಾ ತಲ್ಲಣಗಳಿರುವಾಗಲೇ ನನಗೆ ನೆನಪಾಗುವುದು ಆ ಸ೦ತರ ವಿವೇಕ ವಾಣಿ "ತಲ್ಲಣಿಸದಿರು ಕ೦ಡ್ಯ್ ತಾಳು ಮನವೇ". ಕೊನೆಗೆ ನೀವು ಈ ವಾಣಿಯನ್ನೇ ಅಶ್ರಯಿಸಿದ್ದು ಒ೦ದು ಸ೦ತಸದ ವಿಚಾರ. ಇರಲಿ ನೀವು Global warming ಒ೦ದು Hoax ಎ೦ದು ಕರೆದು ನೆಮ್ಮದಿಯ ನಿರಾಳತೆಯನ್ನು ಅನುಭವಿಸುತ್ತಿರಬಹುದು. ಇಲ್ಲಿ ನಾನು ಕೆಳಗೆ ಉಲ್ಲೇಖಿಸಿರುವ ಸಾಲುಗಳನ್ನೂ ನಿಧಾನವಾಗಿ ಓದಿ ನಿಮ್ಮ ಅಭಿಪ್ರಾಯಗಳನ್ನು ತಿಳಿಸಿ.
Global warming is the increase in the average temperature of Earth's near-surface air and oceans since the mid-20th century and its projected continuation. Global surface temperature increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) between the start and the end of the 20th century.[3][A] The Intergovernmental Panel on Climate Change (IPCC) concludes that most of the observed temperature increase since the middle of the 20th century was very likely caused by increasing concentrations of greenhouse gases resulting from human activity such as fossil fuel burning and deforestation.[3] The IPCC also concludes that variations in natural phenomena such as solar radiation and volcanic eruptions had a small cooling effect after 1950.[4][5] These basic conclusions have been endorsed by more than 40 scientific societies and academies of science,[B] including all of the national academies of science of the major industrialized countries.
Fossil fuels are non-renewable resources because they take millions of years to form, and reserves are being depleted much faster than new ones are being formed. The production and use of fossil fuels raise environmental concerns. A global movement toward the generation of renewable energy is therefore under way to help meet increased energy needs.
The burning of fossil fuels produces around 21.3 billion tonnes (21.3 gigatonnes) of carbon dioxide per year, but it is estimated that natural processes can only absorb about half of that amount, so there is a net increase of 10.65 billion tonnes of atmospheric carbon dioxide per year (one tonne of atmospheric carbon is equivalent to 44/12 or 3.7 tonnes of carbon dioxide).[6] Carbon dioxide is one of the greenhouse gases that enhances radiative forcing and contributes to global warming, causing the average surface temperature of the Earth to rise in response, which climate scientists agree will cause major adverse effects.
All these facts lead scientists to infer that the global warming we now experience is not a natural occurrence and that it is not brought on by natural causes. Man is responsible, they say. What did we do? Read more about the man-made causes and impacts of global warming in the following articles.
But while we are still far from seeing major concentrations of CO2 in our atmosphere, slight changes already alter the way our celestial heating system works. Measurements of carbon dioxide amounts from Mauna Loa Observatory in Hawaii show that CO2 has increased from about 313 ppm in 1960 to about 375 ppm in 2005.

That means for every million particles in our atmosphere, there are now 62 CO2-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.

Methane is number two among the man-made climate warmers worldwide. Its concentration in the atmosphere has increased threefold since the industrial revolution. But with more warming, the worst could still be to come.

Methane, the second most important greenhouse gas after carbon dioxide and the primary component of natural gas, is virtually omnipresent. The odorless, colorless gas leaks from the Earth’s mantle through volcanoes, vents from the stomachs of millions of livestock, rises from wetlands, marshes, and coal mines, and bubbles up from all things decaying.

For the last decade, however, methane emissions had somehow stabilized and even decreased slightly, while carbon dioxide levels increased rapidly. Scientists finally figured out that this was due to the fact that many wetlands were being drained for agricultural use, the increased capture of methane from landfills, and reduced emissions from the production of natural gas. But methane emissions have started to rise again due to increased consumption of fossil fuels in Asia. And an even bigger time bomb is ticking.

A lot of methane is trapped in permafrost soils and under the world’s oceans. Scientists fear that these deposits could be freed by further global warming. This would cause more warming and, in a vicious cycle, the release of even more methane thereby triggering runaway climate change.

Permafrost soil in Siberia has started to melt for the first time since it formed 11,000 years ago at the end of the last ice age. It now threatens to release billions of tons of methane. According to Larry Smith, a hydrologist at the University of California, the west Siberian peat bog alone could hold some 70 billion tons of methane, a quarter of all of the methane stored in the ground around the world.

More methane could come from melting methane deposits in ocean seabeds if water temperatures rise sufficiently. Scientists speculate that large, sudden releases of methane have in the past resulted in periods of rapid global warming and mass extinction events.

This benevolent cycle went on for millions of years until chemists and farmers realized that nitrogen fertilizers greatly increase crop yields. Since then, more and more nitrogen has been added to the cycle. Farmers around the globe use more than 70 million tons of nitrogen fertilizers annually. According to a study conducted by Nobel prize-winning chemist Paul Crutzen in 2007, some 3 to 5 percent of this nitrogen is converted directly into nitrous oxide, twice the amount previously thought

Today, fertilizers are often washed away by rain into lakes and seas where algae feed on them, bloom uncontrollably, and starve the water of oxygen. Every summer, nitrogen-rich river flow from the Mississippi River creates a “dead zone” in the Gulf of Mexico the size of Massachusetts

Mankind’s binge on fertilizers and fossil fuels, another source of the gas, has increased nitrous oxide levels in the atmosphere by about 18 percent since 1750. Fortunately, nitrous oxide appears only in scarce quantities; it is about a thousand times rarer than carbon dioxide. But its long atmospheric lifetime of about 150 years and its strong warming potential, more than 300 times stronger than CO2, make it an effective agent of global warming.

Man-induced increase
Since the beginning of the industrial revolution, the average amount of carbon dioxide in the atmosphere has increased by nearly 40 percent from an estimated 280 to more than 380 ppmv percent. This increase in CO2’s share of the atmosphere is mostly due to anthropogenic (man-induced) factors, such as burning fossil fuels, deforestation and industrial production.

In total, humans emit around 32 gigatons of carbon dioxide each year. Half of this stays in the atmosphere; the rest is absorbed by oceans and vegetation. With sharp increases in man-made CO2 emissions, the natural CO2 cycle gets thrown out of balance: vegetation can no longer transform the increased amount of CO2 into oxygen, and oceans are steadily reaching saturation level. The result of the increasing amount of carbon dioxide in the atmosphere is an enhanced greenhouse effect and, subsequently, climate change. While CO2 is only responsible for 20 percent of the natural greenhouse effect, it accounts for about 60 percent of the anthropogenic greenhouse effect that is causing the latest wave of global warming.

Besides these fundamental natural processes, there are a number of artificial uses of carbon dioxide. Dry ice, for example, used for cooling devices, is nothing but deep-frozen, super-cold carbon dioxide. CO2 can also be found in fire extinguishers and, as the food additive E 290, adds the fizz to soft drinks and sparkling water.

ಆಧಾರ: ವಿಕಿಪೀಡಿಯ
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