What is Global Warming?
"Global Warming is defined as the increase of the average temperature on Earth. As the Earth is getting hotter, disasters like hurricanes, droughts and floods are getting more frequent."
Over the last 100 years, the average air temperature near the Earth’s surface has risen by a little less than 1 degree Celsius or 1.3 degrees Fahrenheit. Doesn't seem that much, does it? Yet it is responsible for the conspicuous increase in storms, floods and raging forest fires we have seen in recent years, say scientists.
Their data show that an increase of one degree Celsius makes the Earth warmer now than it has been for at least a thousand years.The top 11 warmest years on record have all been in the last 13 years, said NASA in 2007, and the first half of 2010 has already gone down in history as the hottest ever recorded.
• Industrialization, deforestation, and pollution have greatly increased atmospheric concentrations of water vapor, carbon dioxide, methane, and nitrous oxide, all greenhouse gases that help trap heat near Earth's surface.(See an interactive feature on how global warming works.)
• Humans are pouring carbon dioxide into the atmosphere much faster than plants and oceans can absorb it.
• These gases persist in the atmosphere for years, meaning that even if such emissions were eliminated today, it would not immediately stop global warming.
Are climate change and global warming one and the same?
In a nutshell: global warming is the cause, climate change is the effect.
Projections from the UN climate change body the Intergovernmental Panel on Climate Change (IPCC) say that global surface temperature will probably rise a further 1.1 to 6.4 degrees Celsius (2.0 to 11.5 degrees Fahrenheit) during the 21st century. The huge range of estimates is due to the amazing complexity of our Earth’s climate system and the uncertainty about whether mankind will fight this warming or continue with business-as-usual.
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. Humanity’s industrial emissions are responsible, they say.
Exactly how these changes will influence the warming trend is unclear. All we know for certain is that it’s going to be warmer and that human greenhouse gas emissions are an important reason for this.
Greenhouse Gases
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 and find out why CO2, methane, and nitrous oxide might become benevolent climate killers — and how we can react. The Greenhouse effect.
Carbon Dioxide
The #1 greenhouse gas.
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.
Carbon dioxide has always been with us. Scientists say Earth’s earliest atmosphere was made up mostly of steam, carbon dioxide, and ammonia from volcanic eruptions. Today, carbon dioxide is mostly produced by the combustion of organic matter like coal, oil, and wood, the fermentation, and the respiration processes of living organisms.
So can we reduce this? Of course we can. We are the producers. BUT does the WORLD want to?
Methane
The #2 greenhouse gas.
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.
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.
One of the most convenient strategies to reduce methane emissions is burning the excess gas that rises from landfills, natural gas production sites, or other natural sources. However, this releases CO2 into the atmosphere, also a greenhouse gas but with a lower global warming potential.
Even better is using the methane to power gas turbines or fuel cars. A number of farmers now use their animals’ manure to produce methane for heating or electricity, while landfills and gas producers switch from simply flaring the gas to actually using it as a source of energy
So can we reduce this? Of course we can. We have the means. BUT does the WORLD want to?
Nitreous Oxide
The #3 greenhouse gas.
Nitrogen is the chemical basis for proteins and DNA; plants need it for photosynthesis and growth. While the gas is the most abundant element of our atmosphere, it cannot be used. Higher organisms have to rely on tiny bacteria to turn it into ammonia or nitrates. Once a plant dies, other bacteria feed on the leftovers and turn nitrates back into gases like nitrous oxide or nitrogen.
This 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.
Fertilizer application will increase with a growing world population. Over the next three decades food production will need to increase by about 60 percent, estimates the UN’s Food and Agricultural Organization. In the same period, nitrous oxide emissions could double, especially in developing countries. 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.
So can we reduce this? Of course we can. We are the producers. BUT does the WORLD want to?
What Could Happen If Not Addressed Seriously?
A follow-up report by the IPCC released in April 2007 warned that global warming could lead to large-scale food and water shortages and have catastrophic effects on wildlife.
• Sea level could rise between 7 and 23 inches (18 to 59 centimeters) by century's end, the IPCC's February 2007 report projects. Rises of just 4 inches (10 centimeters) could flood many South Seas islands and swamp large parts of Southeast Asia.
• Some hundred million people live within 3 feet (1 meter) of mean sea level, and much of the world's population is concentrated in vulnerable coastal cities.
• Glaciers around the world could melt, causing sea levels to rise while creating water shortages in regions dependent on runoff for fresh water.
• Strong hurricanes, droughts, heat waves, wildfires, and other natural disasters may become commonplace in many parts of the world. The growth of deserts may also cause food shortages in many places.
• More than a million species face extinction from disappearing habitat, changing ecosystems, and acidifying oceans.
• The ocean's circulation system, known as the ocean conveyor belt, could be permanently altered, causing a mini-ice age in Western Europe and other rapid changes.
• At some point in the future, warming could become uncontrollable by creating a so-called positive feedback effect. Rising temperatures could release additional greenhouse gases by unlocking methane in permafrost and undersea deposits, freeing carbon trapped in sea ice, and causing increased evaporation of water.
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