Global Warming

Global Warming

Global warming is primarily a problem of too much carbon dioxide (CO2) in the atmosphere—which acts as a blanket, trapping heat and warming the planet. As we burn fossil fuels like coal, oil and natural gas for energy or cut down and burn forests to create pastures and plantations, carbon accumulates and overloads our atmosphere. Certain waste management and agricultural practices aggravate the problem by releasing other potent global warming gases, such as methane and nitrous oxide. See the pie chart for a breakdown of heat-trapping global warming emissions by economic sector.

"Climate change" means a change in climate that persists over a sustained period of time. The World Meteorological Organization defines this time period as 30 years. Examples of climate change include increases in global surface temperature (global warming), changes in rainfall patterns, and changes in the frequency of extreme weather events. Changes in climate may be due to natural causes, e.g., changes in the sun's output, or due to human activities, e.g., changing the composition of the atmosphere. Any human-induced changes in climate will occur against the "background" of natural climatic variations.

Although local temperatures fluctuate naturally, over the past 50 years the average global temperature has increased at the fastest rate in recorded history. And experts think the trend is accelerating: the 10 hottest years on record have all occurred since 1990. Scientists say that unless we curb global warming emissions, average U.S. temperatures could be 3 to 9 degrees higher by the end of the century.

Causes

Global Warming is caused by many things. The causes are split up into two groups, man-made or anthropogenic causes, and natural causes.

Natural Causes

Natural causes are causes created by nature. One natural cause is a release of methane gas from arctic tundra and wetlands. Methane is a greenhouse gas. A greenhouse gas is a gas that traps heat in the earth's atmosphere. Another natural cause is that the earth goes through a cycle of climate change. This climate change usually lasts about 40,000 years.

Man-made Causes

Man-made causes probably do the most damage. There are many man-made causes. Pollution is one of the biggest man-made problems. Pollution comes in many shapes and sizes. Burning fossil fuels is one thing that causes pollution. Fossil fuels are fuels made of organic matter such as coal, or oil. When fossil fuels are burned they give off a green house gas called CO2. Also mining coal and oil allows methane to escape. How does it escape? Methane is naturally in the ground. When coal or oil is mined you have to dig up the earth a little. When you dig up the fossil fuels you dig up the methane as well.

Another major man-made cause of Global Warming is population. More people means more food, and more methods of transportation, right? That means more methane because there will be more burning of fossil fuels, and more agriculture. Now your probably thinking, "Wait a minute, you said agriculture is going to be damaged by Global Warming, but now you're saying agriculture is going to help cause Global Warming?" Well, have you ever been in a barn filled with animals and you smell something terrible? You're smelling methane. Another source of methane is manure. Because more food is needed we have to raise food. Animals like cows are a source of food which means more manure and methane. Another problem with the increasing population is transportation. More people means more cars, and more cars means more pollution. Also, many people have more than one car.

Since CO2 contributes to global warming, the increase in population makes the problem worse because we breathe out CO2. Also, the trees that convert our CO2 to oxygen are being demolished because we're using the land that we cut the trees down from as property for our homes and buildings. We are not replacing the trees (an important part of our eco system), so we are constantly taking advantage of our natural resources and giving nothing back in return.

Effects

Global warming is already causing damage in many parts of the United States. In 2002, Colorado, Arizona and Oregon endured their worst wildfire seasons ever. The same year, drought created severe dust storms in Montana, Colorado and Kansas, and floods caused hundreds of millions of dollars in damage in Texas, Montana and North Dakota. Since the early 1950s, snow accumulation has declined 60 percent and winter seasons have shortened in some areas of the Cascade Range in Oregon and Washington.

Of course, the impacts of global warming are not limited to the United States. In 2003, extreme heat waves caused more than 20,000 deaths in Europe and more than 1,500 deaths in India. And in what scientists regard as an alarming sign of events to come, the area of the Arctic's perennial polar ice cap is declining at the rate of 9 percent per decade.

Global warming doesn't create hurricanes, but it does make them stronger and more dangerous. Because the ocean is getting warmer, tropical storms can pick up more energy and become more powerful. So global warming could turn, say, a category 3 storm into a much more dangerous category 4 storm. In fact, scientists have found that the destructive potential of hurricanes has greatly increased along with ocean temperature over the past 35 years.

Global warming is a complex phenomenon, and its full-scale impacts are hard to predict far in advance. But each year scientists learn more about how global warming is affecting the planet, and many agree that certain consequences are likely to occur if current trends continue. Among these:

·         Melting glaciers, early snowmelt and severe droughts will cause more dramatic water shortages in the American West.

·         Rising sea levels will lead to coastal flooding on the Eastern seaboard, in Florida, and in other areas, such as the Gulf of Mexico.

·         Warmer sea surface temperatures will fuel more intense hurricanes in the southeastern Atlantic and Gulf coasts.

·         Forests, farms and cities will face troublesome new pests and more mosquito-borne diseases.

·         Disruption of habitats such as coral reefs and alpine meadows could drive many plant and animal species to extinction.

The United States. Though Americans make up just 4 percent of the world's population, we produce 25 percent of the carbon dioxide pollution from fossil-fuel burning -- by far the largest share of any country. In fact, the United States emits more carbon dioxide than China, India and Japan, combined. Clearly America ought to take a leadership role in solving the problem. And as the world's top developer of new technologies, we are well positioned to do so -- we already have the know-how.

Solution

We should put existing technologies for building cleaner cars and more modern electricity generators into widespread use. We can increase our reliance on renewable energy sources such as wind, sun and geothermal. And we can manufacture more efficient appliances and conserve energy.

Voluntary reduction programs have failed to stop the growth of emissions. Even leaders of major corporations, including companies such as DuPont, Alcoa and General Electric, agree that it's time for the federal government to create strong laws to cut global warming pollution. Public and political support for solutions has never been stronger. Congress is now considering fresh proposals to cap emissions of carbon dioxide and other heat-trapping pollutants from America's largest sources -- power plants, industrial facilities and transportation fuels.
Stricter efficiency requirements for electric appliances will also help reduce pollution. One example is the 30 percent tighter standard now in place for home central air conditioners and heat pumps, a Clinton-era achievement that will prevent the emission of 51 million metric tons of carbon -- the equivalent of taking 34 million cars off the road for one year. The new rule survived a Bush administration effort to weaken it when, in January 2004, a federal court sided with an NRDC-led coalition and reversed the administration's rollback.
Cost-effective technologies to reduce global warming pollution from cars and light trucks of all sizes are available now. There is no reason to wait and hope that hydrogen fuel cell vehicles will solve the problem in the future. Hybrid gas-electric engines can cut global warming pollution by one-third or more today; hybrid sedans, SUVs and trucks from several automakers are already on the market.
But automakers should be doing a lot more: They've used a legal loophole to make SUVs far less fuel efficient than they could be; the popularity of these vehicles has generated a 20 percent increase in transportation-related carbon dioxide pollution since the early 1990s. Closing this loophole and requiring SUVs, minivans and pick-up trucks to be as efficient as cars would cut 120 million tons of carbon dioxide pollution a year by 2010. If automakers used the technology they have right now to raise fuel economy standards for new cars and light trucks to a combined 40 m.p.g., carbon dioxide pollution would eventually drop by more than 650 million tons per year as these vehicles replaced older models.

GLOBAL WARMING MYTHS

   

Myth 1# Average global temperature (AGT) has increased over the last few years.

 

Fact 1# within error bounds, AGT has not increased since 1995 and has declined since 2002, despite an increase in atmospheric CO2 of 8% since 1995. 

 

Myth 2 # During the late 20th Century, AGT increased at a dangerously fast rate and reached an unprecedented magnitude.

 

Facts 2#  The late 20th Century AGT rise was at a rate of 1-20 C/century, which lies well within natural rates of climate change for the last 10,000 yr. AGT has been several degrees warmer than today many times in the recent geological past. 

 

Myth 3 # AGT was relatively unchanging in pre-industrial times, has sky-rocketed since 1900, and will increase by several degrees more over the next 100 years (the Mann, Bradley & Hughes "hockey stick" curve and its computer extrapolation).

 

Facts 3#  The Mann et al. curve has been exposed as a statistical contrivance. There is no convincing evidence that past climate was unchanging, nor that 20th century changes in AGT were unusual, nor that dangerous human warming is underway.

 

Myth 4 # Computer models predict that AGT will increase by up to 60 C over the next 100 years.

 

Facts 4# Deterministic computer models do. Other equally valid (empirical) computer models predict cooling. 

 

Myth 5 # Warming of more than 20 C will have catastrophic effects on ecosystems and mankind alike.

 

Facts 5#  A 20 C change would be well within previous natural bounds. Ecosystems have been adapting to such changes since time immemorial. The result is the process that we call evolution. Mankind can and does adapt to all climate extremes.

 

Myth 6 # Further human addition of CO2 to the atmosphere will cause dangerous warming, and is generally harmful.

 

Facts 6 # No human-caused warming can yet be detected that is distinct from natural system variation and noise. Any additional human-caused warming which occurs will probably amount to less than 10 C. Atmospheric CO2 is a beneficial fertilizer for plants, including especially cereal crops, and also aids efficient evapo-transpiration. 

 

Myth 7 # Changes in solar activity cannot explain recent changes in AGT.

 

Facts 7# The sun's output varies in several ways on many time scales (including the 11-, 22 and 80-year solar cycles), with concomitant effects on Earth's climate. While changes in visible radiation are small, changes in particle flux and magnetic field are known to exercise a strong climatic effect. More than 50% of the 0.80 C rise in AGT observed during the 20th century can be attributed to solar change. 

 

Myth 8 #  Unprecedented melting of ice is taking place in both the north and south polar regions.

 

Facts 8 # Both the Greenland and Antarctic ice sheets are growing in thickness and cooling at their summit. Sea ice around Antarctica attained a record area in 2007. Temperatures in the Arctic region are just now achieving the levels of natural warmth experienced during the early 1940s, and the region was warmer still (sea-ice free) during earlier times.

 

Myth 9 #  Human-caused global warming is causing dangerous global sea-level (SL) rise.

 

Facts 9#  SL change differs from time to time and place to place; between 1955 and 1996, for example, SL at Tuvalu fell by 105 mm (2.5 mm/yr). Global average SL is a statistical measure of no value for environmental planning purposes. A global average SL rise of 1-2 mm/yr occurred naturally over the last 150 years, and shows no sign of human-influenced increase. 

 

Myth 10 # The late 20th Century increase in AGT caused an increase in the number of severe storms (cyclones), or in storm intensity.

 

Facts 10# Meteorological experts are agreed that no increase in storms has occurred beyond that associated with natural variation of the climate system.

MYTH 11# Scientists can’t agree. The jury is still out.

Fact:  An overwhelming majority of scientists agree that human activity is largely responsible for recent warming. There is consensus among scientists that the climate is being changed by human activity, in the same way as there is consensus on the existence of gravity or that the Earth is round.
 MYTH 12#. It’s just part of natural change.
Fact:  The climate has changed throughout the Earth’s history but this isn’t the same as saying that global warming in today’s era is natural. In fact, past changes help scientists to understand the sensitivity of the global climate to forces such as the Sun, volcanoes and greenhouse gases.
 MYTH 13#. The globe has stopped warming.
Fact:  Temperature records clearly show the world has continued to warm over the past century.
 MYTH  14#. It’s the sun.
Fact:  The Sun obviously has a big influence on the Earth but changes in the Sun’s activity cannot explain the rise in global temperatures in recent decades. If anything, the Sun’s output has diminished in recent decades yet the world is still warming.
 MYTH  15#. Scientists have exaggerated claims that the world’s glaciers are disappearing.
Fact:  The IPCC’s 2007 assessment report holds up extremely well under the most rigorous, independent scrutiny. It’s important to keep things in perspective: Among hundreds of pages of projected regional impacts, only three “significant errors” have been confirmed, all of which were honest mistakes and none of which affect the IPCC’s overarching advice.
 MYTH  16#. Volcanoes emit more carbon dioxide than humans possibly could.
Fact:  Volcanoes emit less than 1% of the CO₂ humans put into the atmosphere in a year. This percentage is growing smaller as emissions from human activities continue to rise.
 MYTH  17#. Carbon dioxide is not a pollutant; it’s natural and essential for life.
Fact:  ‘Natural’ does not always equal ‘safe’. Rapidly increasing high concentrations of CO₂ and other greenhouse gases generated by human activity are jeopardising human health and wellbeing, as are most pollutants.
 MYTH  18#. Far back in time, global warming episodes had nothing to do with carbon dioxide levels.
Fact:  Carbon role of CO₂ in the planet’s history is reasonably well understood. While changes in CO₂ levels are certainly not the only force at work on the climate, past climate change cannot be explained without an understanding of the greenhouse properties of CO₂.
 MYTH 19#. Australia has always had droughts, heat waves and extreme bushfire weather. There is no link to climate change.
Fact:  Droughts, heat waves and bushfires are far from unusual in Australia but many scientists say there is a human signature in recent extreme events, making Australia’s already highly variable climate even more hostile.
 MYTH 20#. Global Warming is good for us!
Fact:  While we can all hope for the best, left unchecked, climate change will undoubtedly make life a lot harder for a great many people, especially the world’s poor who can least afford to adapt.