Atmospheric carbon dioxide concentrations
and global annual average temperatures
over the years 1880 to 2009 Global warming refers to the warming of the entire earth by the greenhouse effect. The greenhouse effect is the process in which the gases in the Earth's atmosphere catch infrared radiation from the Earth—the same a greenhouse does. Infrared radiation is what keeps the Earth warm at night when the sun is not warming it. If it doesn’t occur most life on earth would perish. But if occurs too much the Earth heats up to harmful levels.
When sunlight strikes the Earth's atmosphere, some sun rays bounces off into space but most penetrates the atmosphere and makes their way to earth's surface. Most of the heat is absorbed by bands of air a few kilometers from the ground. Some of this heat is radiated into space in the form on infrared radiation. Some escapes the atmosphere but most is redirected back towards the Earth like the glass of a greenhouse by greenhouse gases such as carbon dioxide, methane, nitrous oxide, and water vapor.
Global warming today often refers to the heating of the Earth through an increase in greenhouse gases caused by human activity. Consequences of global warming potentially include changing climatic patterns, turning productive agricultural land into desert, melting glaciers and ice caps, lowering freshwater supplies, raising the level of the oceans, and flooding coastal cities.
In July 2005, the head of the National Academy of Sciences, climatologist Ralph Cicerone appeared before the U.S. Congress and said: “Nearly all climate scientists today believe that much of the Earth’s current warming has been caused by increases in the amount of greenhouse gases in the atmosphere, mostly from burning fossil fuels.
Elizabeth Kolbert wrote in National Geographic, “Since the start of the industrial revolution, enough fossil fuels—coal, oil, and natural gas—have been burned and enough forests cut down to emit more than 500 billion tons of CO2. As is well known, the atmosphere has a higher concentration of CO2 today than at any point in the past 800,000 years and probably a lot longer. [Source: Elizabeth Kolbert, National Geographic, April 2011]
Global Temperatures in 2010 Second Highest Since 1891
GlobalTemperaturesSince1991 According to NASA, 2005 was the warmest year on record and 2009 was the second warmest year. The 2000s were the warmest decade in record. The hottest years have all occurred since 1998. Kyodo news agency reported: “Due to global warming, the worldwide temperature on land and the sea surface in 2010 rose 0.36 C from the 1971 to 2000 average, marking the second highest increase since comparable data became available in 1891, according to Japanese meteorologists. The existing record rise is 0.37 C marked in 1998. [Source: Kyodo December 22, 2010]
The global temperature only on land went up 0.68 C, hitting a new high, the Japan Meteorological Agency said. Japan's average temperature rose 0.85 C from the 30-year average, matching the fourth highest since 1898. The weather agency worked out the figures based on data from January through November, Kyodo reported. The Japanese meteorologists attributed the rise in the average temperature to global warming caused by emissions of greenhouse gases and a rise in the sea surface temperature caused by the El Nino climate pattern.
The Japan Meteorological Agency said the global temperature climbed by 0.68 C in the past 100 years and Japan's temperature by 1.15 C during the past century. The average temperature in some parts of Greenland and Canada in 2010 went up by 4 to 5 C, the report said. Japan's average temperature in the June to August summer season in 2010 was the highest ever, but the low temperature in the March to May spring season dragged down the yearly average.Meanwhile, the number of tropical depressions that developed into typhoons in 2010 is expected to stay at 14, the smallest figure since 1951 when comparable data was available, the agency said in a separate report. The existing low is 16 recorded in 1998. The average number in the 1971 to 2000 period is 26.7.
The year 2010 was among the top three warmest since records began in 1850, and the past decade was the warmest, the United Nations said. According to the U.S. government’s National Oceanic and Atmospheric Administration (NOAA) year 2010 was slightly warmer than both 1998 and 2005 going into to December but ended up tied with 2005 as the warmest year on record as December was a cool month.
The U.N.’s World Meteorological Organization (WMO) said in a report issued on the sidelines of U.N. climate talks in Cancun Mexico in December 2010: “The trend is of very significant warming.” When WMO head Michel Jarraud was asked if the data were new evidence that emissions of greenhouse gases were warming the climate, he said: “Short answer: yes...These are the facts. If nothing is done … (temperatures) will go up and up.”
The WMO said that land and sea surface temperatures in 2010 were 0.55 degree Celsius (1 F) above a 1961-1990 average of 14 degrees Celsius (57.2 degrees F). The years 2001-10 were the warmest decade, it said. The WMO said that warming has been especially strong in Africa, parts of Asia and parts of the Arctic. Pakistan recorded a record temperature of 53.5 degrees Celsius (128.30 F), the warmest in Asia since 1942.
The greenhouse effect
Carbon Dioxide in the Atmosphere
Each year humans release about 7 billion metric tons of carbon dioxide into the Earth’s atmosphere: about 6.5 million tons is from fossil fuels, 1.5 billion from deforestation. Carbon dioxide emissions from automobiles, power plants and factories grew 1.1 percent in the 1990s and grew 3 percent from 2000 to 2004.
Carbon dioxide concentrations in the atmosphere were 180 parts per million (p.p.m.) during the last Ice Age. In the 18th century, before the onset of the Industrial Revolution and intensive burning of coal they stood at 280 p.p.m, then reached 315 p.p.m. in the 1950s and have since climbed to over 380 p.p.m. today.
Comparing current air to air bubbles trapped in Antarctic ice Edward Brook of Oregon State University reported in Science that there is more carbon dioxide in the air now than there has been at any time in the last 650,000 years. Others have put the figure at 800,000 years.
Carbon Dioxide Levels Jump to Record Levels in 2010
AP in November 2011: The global output of heat-trapping carbon dioxide jumped by the biggest amount on record, the U.S. Department of Energy calculated, a sign of how feeble the world's efforts are at slowing man-made global warming. The new figures for 2010 mean that levels of greenhouse gases are higher than the worst case scenario outlined by climate experts just four years ago. "The more we talk about the need to control emissions, the more they are growing," said John Reilly, co-director of MIT's Joint Program on the Science and Policy of Global Change. [Source: AP, November 3, 2011]
Global Surface Temperatures in 2005
The world pumped about 564 million more tons of carbon into the air in 2010 than it did in 2009. That's an increase of 6 percent. According to a BP report emissions grew 5.8 percent in 2010 to 33.16 billion tonnes, as countries rebounded from economic recession. China's emissions totaled 8.33 billion tonnes, the BP report said, up 10 percent from the year before.
That amount of extra pollution eclipses the individual emissions of all but three countries - China, the United States and India, the world's top producers of greenhouse gases. It is a "monster" increase that is unheard of, said Gregg Marland, a professor of geology at Appalachian State University, who has helped calculate Department of Energy figures in the past. Extra pollution in China and the U.S. account for more than half the increase in emissions last year, Marland said.
"It's a big jump," said Tom Boden, director of the Energy Department's Carbon Dioxide Information Analysis Center at Oak Ridge National Lab. "From an emissions standpoint, the global financial crisis seems to be over." Boden said that in 2010 people were traveling, and manufacturing was back up worldwide, spurring the use of fossil fuels, the chief contributor of man-made climate change.
India and China are huge users of coal. Burning coal is the biggest carbon source worldwide and emissions from that jumped nearly 8 percent in 2010. The world is slowly using more coal and less natural gas when it should be doing just the opposite because of climate change, Marland said.
In 2007 when the Intergovernmental Panel on Climate Change issued its last large report on global warming, it used different scenarios for carbon dioxide pollution and said the rate of warming would be based on the rate of pollution. Boden said the latest figures put global emissions higher than the worst case projections from the climate panel. Those forecast global temperatures rising between 4 and 11 degrees Fahrenheit by the end of the century with the best estimate at 7.5 degrees. "Really dismaying," said Granger Morgan, head of the engineering and public policy department at Carnegie Mellon University. "We are building up a horrible legacy for our children and grandchildren."
Kyodo reported in November 2010: The world's carbon dioxide emissions from fossil fuels fell only moderately in 2009 despite the global economic downturn as those in China and other emerging economies remained robust, a report by an international research team. The report in the online edition of the British science magazine Nature Geoscience said global CO2 emissions fell by a smaller-than-expected 1.3 percent even after the financial crisis triggered by the collapse of major U.S. investment bank Lehman Brothers Holdings Inc. In the fall of 2008. [Source: Kyodo, November 21, 2010]
Emissions in 2009 fell 11.8 percent in Japan, 6.9 percent in the United States and 8.6 percent in Britain, but increased 8.0 percent in China, 6.2 percent in India and 1.4 percent in South Korea.''Regardless of the speed of economic growth, the overall trend of emissions increase is unlikely to change,'' said Yoshiki Yamagata, a researcher at the National Institute for Environmental Studies in Tsukuba, Ibaraki Prefecture, which was involved in the study.
carbon cycle on a larger scale
Carbon is the chemical backbone of life on Earth, a key element in many important processes. Carbon compounds help to regulate the Earth’s temperature, make up the food that sustains us, and provide a major source of the energy to fuel our global economy. Most of Earth’s carbon is stored in rocks and sediments, while the rest is located in the ocean, atmosphere, and in living organisms - these are the reservoirs through which carbon cycles. Carbon Storage and Exchange
Carbon moves from one storage reservoir to another through a variety of mechanisms. One example is the movement of carbon through the food chain. Plants move carbon from the atmosphere into the biosphere through photosynthesis: they take in carbon dioxide and use energy from the sun to chemically combine it with hydrogen and oxygen to create sugar molecules. Animals that eat the plant can digest the sugar molecules to get energy for their bodies. Respiration, excretion, and decomposition release the carbon back into the atmosphere or soil continuing the cycle.
The ocean plays a critical role in the storage of carbon, as it holds about 50 times more carbon than the atmosphere. Two-way carbon exchange can occur quickly between the ocean’s surface waters and the atmosphere, but carbon may also be stored for centuries at the deepest ocean depths.
Rocks such as limestone and fossil fuels such as coal and oil are storage reservoirs that contain carbon from plants and animals that lived millions of years ago. When these organisms died, slow geologic processes trapped their carbon and transformed it into these natural resources. Processes such as erosion release this carbon back into the atmosphere very slowly while volcanic activity can release it very quickly. Burning of fossil fuels in cars or power plants is another way this carbon can be released into the atmospheric reservoir quickly.
The increasing human population and their activities have a tremendous impact on the carbon cycle. Burning of fossil fuels, changes in land use, and the use of limestone to make concrete all transfer significant quantities of carbon into the atmosphere. As a result the amount of carbon dioxide (CO2) in the atmosphere is rapidly rising and is already significantly greater than at any time in the last 800,000 years. This increase of CO2 is affecting our ocean as it absorbs much of the CO2 that is released from burning fossil fuels. This extra CO2 is lowering the ocean’s pH, this process is called ocean acidification and interferes with the ability of marine organisms (such as corals) to build their shells and skeletons.
Evidence of Global Warming
Changes in climate indicators
that show global warming In the 20th century global temperatures rose by 1° Fahrenheit (or 0.6° Centigrade) with two distinct period of warming: one between 1910 and 1945 and the other between 1976 and 2000. The 1990s were the hottest decade on record. Since the Industrial Revolution global carbon dioxide levels have increased by 30 percent. Some say temperatures now may be the highest they have been in the last 20 million years.
The amount of greenhouse gases in the atmosphere rose from 280 parts per million (ppm) in the 19th century to around 480 ppm today and is expected to reach 550 ppm between 2035 and 2050. Data released in March 2006, indicated that carbon dioxide levels were increasing at a rate double that of the mid 1970s. The amount greenhouse gases released into the atmosphere increased 70 percent between 1970 and 2004 and is expected to rise another 25 percent to 90 percent by 2030.
The Earth currently seems to be heating up at an alarming rate, faster than researchers predicted or anticipated. As of 2007 the 10 warmest years had all occurred since 1994. A study released in 2006 showed that 2005 was the hottest year on record, followed y 1998, 2002, 2003, and 2004, and that temperatures rose one degree F between 1975 and 2005, higher than the rate between 1900 and 1975. Global temperatures in 1998 were high in part because of an El Niño phenomena. What was alarming about 2005 was that year there was no El Niño and the year was also unusually stormy and dry. By 2026 it is estimated the global temperature will be 2°C above what it was in 1750.
Not all the evidence is conclusive. There is evidence that temperatures in Northern Hemisphere have increased by 2°F since the Industrial Revolution while temperatures in the rest or the world have cooled. Some studies said temperature in the Antarctic have risen 3.6°C since the 1970s while other data suggests temperatures are dropping at the South Pole. Global temperatures have fluctuated throughout history. The so-called Little Ice Age that began in the 14th century; and some say it continued until the 1860s. This followed a warm period in the 8th through 10th centuries.
The jury is still out on how quickly temperatures will rise in the future and the consequences these rises will have. Estimates of global warming temperature changes in the 21st century range from 1.1 degrees C to 6.4 degrees C. The “best estimates” by the Intergovernmental Panel of Climate Change (IPCC) put the figure at 3.2 to 4 degrees C (from pre-industrial times by 2100). Some scientists predict that temperatures will rise 5.8°C by 2100 and say a temperature rise of over 4 degrees F would “imply changes that constitute practically a different planet.” Other say if stringent measures are taken the figure could be reduced to 2 to 2.4 degrees.
Further evidence of global warming includes: increases in the temperature of the world's oceans over the last four decades and melting and retreating ice caps and glaciers. The 2000s was the hottest decade on record. Still global temperatures were largely stable during the 2000s The plateau occurred after a sharp rise in the 1990s. Some predict global temperatures may even drop in upcoming years. This evidence is embraced by global warming skeptics who say day that the doom and gloom scenarios painted by many scientists is greatly exaggerated.
Major Studies on Global Warming
CO2 Mauna Loa The Keeling Curve is a graph which plots the ongoing change in concentration of carbon dioxide in Earth's atmosphere since 1958. It is based on continuous measurements taken at the Mauna Loa Observatory in Hawaii under the supervision of Charles David Keeling of the Scripps Institution of Oceanography at UC San Diego. Keeling's measurements showed the first significant evidence of rapidly increasing carbon dioxide levels in the atmosphere. Many scientists credit Keeling's graph with first bringing the world's attention to the issue of in the issue of global warming and climate change.
Keeling was the first person to make frequent regular measurements of the atmospheric carbon dioxide (CO2) concentration, taking readings in Hawaii from 1958 onwards. The measurements collected at Mauna Loa show a steady increase in mean atmospheric CO2 concentration from about 315 parts per million by volume (ppmv) in 1958 to 392 ppmv as of July 2011. This increase in atmospheric CO2 is considered to be largely due to the combustion of fossil fuels, and has been accelerating in recent years.
In 1998, Michael Mann of the University of Massachusetts in Amherst, published the so called “hockey stick” graph that showed a sharp hockey-stick-like upturn in carbon dioxide level beginning at the time of the industrial revolution. The data for older dates came from judging historical temperatures and carbon dioxide levels based on tree rings, ice core samples and coral reef data. Critics of this study didn’t like the reliance on tree rings for historical temperatures.
A study released in 2005 based in satellite measurements and date collected from the sea buoys indicated the Earth is absorbing more energy from the sun than it is emitting back into space as heat. This is in line with what is expected from global warming.
Instrumental Temperature Record In June-August 2009 the world’s ocean surface temperature, according to NOAA, was the warmest it has ever been since 1880 when such measurements began. The high temperature were attributed to El Nino weather patterns and the affects of global warming. Temperatures in the North Atlantic have increased as much as 2 degrees C since the 1990s. Fish such as blue sharks and flounder have been seen in waters off of Iceland further north than they have ever been seen before.
Data from satellites and weather balloons indicates that the troposphere, the part of the atmosphere near the Earth’s surface, is warming up, while the stratosphere, the atmospheric layer, above the troposphere, is cooling. This contradicts the idea that warming is being caused by a hotter sun.
IPCC Reports on Global Warming
According to a report by the Intergovernmental Panel of Climate Change (IPCC)—the United-Nations-sponsored research body made up of nearly 2,500 scientist from 130 countries, whose results are accepted by more than 100 countries— “Warming of the climate system is unequivocal.” In a series of reports released in 2007 the IPCC warned of devastating floods, hurricanes, and typhoons associated with global warming and said 30 percent of the world’s animal and plant species could become extinct and hunger and famine could affect 500 million people and water shortages could affect billions if something isn’t done soon and said with 90 percent certainty that global warming is man-made.
An updating of the 2007 report in 2009 insisted global warming was worse than originally predicted: “The worst-case IPCC scenario trajectories are being realized....There is a significant risk that many of the trends will accelerate, leading to an increasing risk of abrupt or irreversible climate shifts.”
The 3000-page Third Assessment Report —an IPCC document released in 2001 containing peer-reviewed studies by thousands of oceanographers, climatologists, geographers and other scientists—predicted the Earth will warm between 2.5 and 10.4 degrees in terms of the global mean by 2100 unless greenhouse gas emission are cut below current levels. Third Assessment Report —an IPCC
The IPCC issued its first report in 1990 and issued others in 1995 and 2001. In 2007, it and Al Gore were awarded the Nobel Peace Prize for their efforts to spread awareness about climate change. The Pew Center on Global Climate Change is another influential group involved in climate change issues. There are any others organizations also involved with the issue.
Measuring Global Warming
Carbon History Keeling (of the Keeling Curve mentioned above) had perfected the measurement techniques and observed "strong diurnal behaviour with steady values of about 310 ppm in the afternoon" at three locations: Big Sur near Monterey, the rain forests of Olympic Peninsula and high mountain forests in Arizona. By measuring the ratio of two isotopes of carbon, Keeling attributed the diurnal change to respiration from local plants and soils, with afternoon values representative of the "free atmosphere". By 1960, Keeling and his group established the measurement record that was long enough to see not just the diurnal and seasonal variations, but also a year-on-year increase that roughly matched the amount of fossil fuels burned per year. In the article that made him famous, Keeling observed, "at the South Pole the observed rate of increase is nearly that to be expected from the combustion of fossil fuel".
Today measurements of carbon dioxide and other gases and materials are taken in 15-foot-long tubes in places like Iceland and Algeria and are sent to Boulder, Colorado where they are analyzed in a high-tech laboratory.
Temperatures in the past can be determined from tree rings (wider rings mean warmer years), corals (which produce layers whose density varies according to the sea temperatures at the times they were deposited), fossil shells (shells of some macroscopic organisms provide clues on sea temperatures in ancient times), and ice cores (chemical compositions of trapped air samples are different in warm years than in cold ones).
Scientists also examine glacier moraines, sand dunes, microscopic shells and organisms buried in deep sea sediments. Cores taken from lakes show pollen levels from ancient times. Isotopes of uranium in stalactites and deposits of mud provide clues about flooding, and rainfall levels. Seeds, leaves, twigs collected by pack rats and preserved in their crystalized urine and feces gives scientists an idea of what plants were living as far back as 30,000 years ago.
Sources of Carbon Dioxide and Greenhouse Gases
Carbon sources Greenhouse gas sources linked to global warming: carbon dioxide (72 percent ), methane (18 percent), nitrous oxide (9 percent), other gases (1 percent)
About half the carbon dioxide released into the atmosphere comes from natural sources and half from human causes. The main man-made contributor to the greenhouse affect in the world today is the burning of fossil fuels such as coal and oil by vehicles and factories. About 80 percent of the increase in man-made carbon dioxide is attributed to the burning of fossil fuels, with 60 percent of that coming from industrialized nations. The United States produced 5.8 billion metric tons of carbon dioxide in 2003 alone, most of it from cars and coal-fired power plants. Large amounts are also spewed out of factories and oil and gas rigs.
Agriculture and forestry account for 30 percent of greenhouse gases. Plowing releases carbon dioxide. Rice fields are another major source. Cattle, sheep and pigs belching and excreting methane are another major source of greenhouse gases.
The remaining 20 percent comes mainly from deforestation. The burning of forests adds carbon dioxide to the atmosphere. The absence of trees prevents them from soaking up carbo dioxide and producing oxygen. Grassland soil and plants store large amounts of carbon dioxide. When they are burned they release large amounts of carbon dioxide into the atmosphere and contribute to global warming.
Other contributors include leaky pipelines, which release natural gas, and depletion of sea life, which can absorbs carbon dioxide. Carbon dioxide can remain in the ocean for 100 years or more before it is recycled or it can be recycled right away. Jet travel is the fastest-growing source of greenhouse gases. Aircraft release more than 6000 million tons of carbon dioxide into the atmosphere every year, accounting for 3.5 percent of global warming. Compared to driving the same distance, a short haul flight generates 21 percent more carbon dioxide per passenger.
Glaciers, Climate and Volcanoes
Among the more prominent theories of events that have triggered major global climatic changes in the distant past and lead to repeated glaciation are: 1) known astronomical variations in the orbital elements of the Earth (the so-called Milankovitch theory); 2) changes in energy output from the Sun; and 3) increases in volcanism that could have thrown more airborne volcanic material into the stratosphere, thereby creating a dust veil and lowered temperatures.
The years 1980, 1981, and 1982, for example, saw several major volcanic eruptions adding large quantities of particulate volcanic material and volatiles to the stratosphere, including the catastrophic eruption of Mount St. Helens, Washington, on May 18, 1980: a large eruption of Mount Hekla, Iceland, on August 17, 1980; and the 1982 series of eruptions from El Chichón volcano in Mexico. These eruptions ejected enormous amounts of volcanic material into the stratosphere, which blocked the sun and caused cooling that lingered for several years. About 17 million tons of sulfur dioxide was released by the Pinatubo eruption in the Philippines in 1991. The sulfur dioxide and ash from that eruption produced a cooling effect that lasted several years.
The potential climatic effect of the Laki volcanic eruption in Iceland in 1783, the largest effusive (lava) volcanic eruption in historic time, was noted by the diplomat-scientist Benjamin Franklin in 1784, during one of his many sojourns in Paris. Franklin concluded that the introduction of large quantities of volcanic particles into the Earth's upper atmosphere could cause a reduction in surface temperature, because the particles would lessen the amount of solar energy reaching the Earth's surface. The catastrophic eruption of the Tambora volcano, Indonesia, in 1815 was followed by a so-called "year-without-a-summer." In New England, for example, frost occurred during each of the summer months in 1816.
Methane, Nitrous Oxide and Volcanic Particles
Methane makes up about a fifth of greenhouses gases. It is 23 times more powerful in terms of trapping heat in the atmosphere than carbon dioxide and lasts 12 years in the atmosphere before it oxidizes and converts to carbon dioxide and water. Levels of methane have increased over 150 percent since the pre-industrial age. Sources include flooded rice paddies, peat bogs, coal mining, rubbish heaps and melted permafrost. According to one estimate a third of the world’s methane may come from termite farts. Other animals also produce large amounts of methane (See Below).
Methane sources: agriculture (40 percent), fossil fuel (30 percent), water disposal (18 percent), land use and biomass burning (7 percent) and residential and commercial (5 percent). A recent study by German scientists a the Max Planck Institute in Heidelberg found 10 percent to 30 percent of new methane emissions come from plants. Concentrations of methane have tripled in the past 150 years.
About 14 percent of the global methane emissions come from farm animal flatulence and belches, mostly from cattle, dairy cows and sheep. Scientists at the Rowett Research Institure in Aberdeen, Scotland have come up with sweet-smelling food additives made with fumaric acids that reduce methane emissions by 70 percent. Japanese scientists at Obihiro University have made similar progress against belches using cysteine (a type of amino acid) and nitrates in cattle feed to suppress methane production during digestion so that the belches contain no methane.
Much of the methane produced by agriculture comes from paddy fields, so much so that rice emits more greenhouse gases than other crop. The source of the methane is bacteria that thrives in flooded paddies.
Nitrous oxide has been called the worst greenhouse gas. On top of that it slowly depletes the ozone layer. Better known as laughing gas, nitrous oxide is 296 times more powerful from a global warming perspective than carbon dioxide and has recently replaced chlorofluorocarbons (CFCs) as the primary cause of ozone depletion. About a third of the world’s nitrous oxide emission are caused by human activities, including the use of fertilizer, fossil fuels, livestock manure and industry. One of the primary methane sources is manure from dairy cows, cattle and other animals. The other two thirds come from nature, mostly releases from soil bacteria. A study by the U.S. National Oceanic and Atmospheric Administration published in Science in September 2009, called nitrous oxide emission “the single most important ozone-depleting substance emission and is expect to remain the largest throughout the century.”
HFC23, a hydroflurocarbon, is greenhouse gas whose impact on global warming is 11,700 times greater than that of carbon dioxide.
Global Warming, Coal and Fossil Fuels
fuels and energy Coal is one of the largest sources of global-warming-producing, greenhouse gases. Coal produces more carbon dioxide per unit than any other fossil fuel. Carbon dioxide emitted per kilowatt hour: 1) coal, 2.1; 2) petroleum, 1.4; 3) natural gas, 0.8. About a quarter of the world’s carbon dioxide emissions come from coal-burning power plants. All the use of coal together account for about 40 percent of carbon dioxide emissions. If new power plants are built the situation will get worse.
The new modern plants also still release millions of tons of carbon dioxide, as much as 11 million tons a year, only slightly less than similar sized plant built 30 years ago. Almost all the carbon dioxide is released in the atmosphere. There is no easy method to capture carbon dioxide and dispose of it.
The World Bank has issued warning abut the consequences of global warming and said the world must wean itself off fossil fuel but at the same time is funding new coal-fired plans in the developing countries such as India, South Africa and Botswana. Marianne Fay, the bank’s chief economist told the Times of London, “There are a lot poor countries which have coal reserves, and for them it’s the only option. Our policy is to continue finding coal to the extent that there no alternative and to push for the most efficient coal plants possible Frankly, ut would be immoral at this stage to say, ‘We want to have clean hands, therefore we are not going to touch coal.’”
Carbon Dioxide Absorption and Seasonal Changes
Some scientists have suggest that global warming would be even worse than it now were it not particle pollution and volcanic eruptions shadowing the Earth and producing a cooling effects. Global warming would also be a lot worse than it is if all of remained in the atmosphere. About 40 percent of the carbon dioxide produced by fossil fuels is soaked up. Where the it goes no one is completely sure.
Carbon dioxide levels change on a seasonal basis with decreases in the spring and summer when plant life is absorbing carbon dioxide through photosynthesis and increases in the fall and winter when less photosynthesis takes place.
Much of the missing carbon is believed to be soaked up by the ocean, which has the capacity to ingest huge amounts of carbon dioxide.
In the laboratory, plants that are given more carbon dioxide grow faster and soak up more carbon dioxide. If this phenomena were true in the real world excess carbon dioxide could cause plants to grow faster and soak up carbon dioxide but unfortunately that is not the case. Studies have shown that plants undergo an initial burst of growing when given more carbon dioxide but that tapers of off later.
Models of Global Warming
Scientists have devoted a lot of time and money to creating very complex supercomputer models that attempt to predict global warming and its consequences. The jury is still out on how well these models predict the future. Also whether climatic and weather variations are caused by global warming or natural weather changes is difficult to say.
Scientifically connecting a weather disaster with global warming is a complicated and time-consuming task that can take more than a year and involve lots of computer calculations. One of the big question marks in fully grasping the impact of global warming is the influence of clouds. For example if the atmosphere warms this causes more evaporation and cloud production. The clouds and water vapor can act like greenhouses gases to trap heat. They can also reflect and absorb heat coming in from the sun. The affects on these phenomena are on global warming are not really known and are very difficult to predict or model.
Other important variables include: 1) the amount of sea ice, which promotes cooling by reflecting sunlight into space; 2) the amount of plants of trees which absorb carbon dioxide; and 3) melting of permafrost, which releases carbon dioxide and methane.
One study by Gerald Roe and Marcia Bka the University of Washington in Seattle published in Science in 2007 found that even though scientists now possess mountains of data about global warming they are no better predicting its effects than 20 years earlier. One of the main findings was that as temperatures rise the outcomes of those rises become more uncertain and thus it becomes more difficult to predict their consequences
Sometimes it is difficult to understand what is really going when one is bombarded with often contradictory data. W. Tad Pfeffer, an expert on Greenland’s ice sheets at the University of Colorado, told New York Times, “One of the things that troubles me most is that the rapid-fire publication of unsettled results in highly visible venues creates the impression that the scientific community has no idea what’s going on...each new paper negate or repudiates something emphatically asserted in a previous paper. The public is obviously picking up on this not as an evolution of objective scientific understanding but as a proliferation of contradictory opinions.”
Global Warming in the Past
The Swedish scientist Svante Arrhenius (1859-1927), using a slide and pencil to make months of tedious calculations, was the first to make note that carbon dioxide would warm the planet. But he calculated it wouldn’t happen for 3,000 another years.
Research by Michael Story of the Roskilde University in Denmark indicates a period of global warming that occurred 55 million years ago that caused the Arctic to become tropical. The warming appears to have been was caused by a series of volcanic eruptions in what is now Greenland that caused the European and North American continents to split apart and generated large amount of magma that cooked peat and coal— and oil-forming organic material— and released large amounts of carbon dioxide. Perhaps most worrisome is that Story estimated that the amount of carbon released was on par with that produced by mankind over a longer period of time and the fact it took 100,000 years for the Earth to recover after European magama shock.
Ice Age temperatures A study by Peter Mayhew of the University of York, England, published in the Proceedings of the Royal Society, found that the five periods in earth is history with the highest levels of extinctions were all associated with climate change. Higher temperatures were linked to four of the mass extinctions in the last 525 million to 65 million years ago.
William Ruddiman, a professor emeritus at the University of Virginia, has suggested that human influence on climate goes way back before the Industrial Revolution to the dawn of history when man began clearing forests for agriculture and accelerated when rice agriculture became widespread. Ruddiman and Erle Ellis, a professor at the University of Maryland, wrote in the journal Quaternary Science Review that carbon dioxide levels began increasing about 8,000 years, around the time when early Europeans began burning and clearing forests, and methane levels began rising around 5,000 years ago when the Chinese began flooding lowlands to raise rice. Today the burning and clearing of tropical rainforests is a major cause of carbon dioxide emissions and rice agriculture is a major producer of methane. The presence of carbon dioxide and methane in the atmosphere thousands of years ago was determined by examining bubbles of air trapped for thousands of years in polar ice. Many scientists have trouble with the findings and don’t like what it implies: that global warming has been occurring for some time and we are no more worse off as a result.
Scientists are examining the logbooks of Captain James Cook and other explorers to gain insights into climate change in the past. Cook meticulously recorded detailed weather reports on each day of his voyages in a wide range of locations around the globe. His logs and those of William Bligh’s Bounty , the Beagle , the ship that carried Charles Darwin and 300 other 18th and 19th century explorers and ships are being transcribed and digitized so climatologists can examine weather patterns as they have occurred and changed over decades and centuries. The information is vital in that there are plenty of land-based reports but few reports from locations at sea and in remote places. Many of the reports have precise latitude and longitude locations as well as accurate data on temperature, ice formation, air pressure and wind speed. Among the findings so far have been a better understanding of the impact of the Mount Tambora eruption in Indonesia in 1815 that ejected so much sun-reflecting sulfur dioxide it caused temperatures to drop around the globe.
Inevitability of Global Warming in the Future
It is going to be hard to stop global warming. Even if emissions are reduced to zero today temperatures will likely continue to rise as a result of the time it takes for heating to reach its maximum effect on the atmosphere. There are still a lot of uncertainties though. The goal by global warming policy makers at this juncture is to contain the damage even though objectives and goals may be uncertain because it is not clear what the thresholds are.
In many ways the argument is beginning to shift from if to when with a certain degree of resignation that the consequence of global warming are inevitable and too much irreversible damage has already been done. In line with this thinking is the belief that one is better to make preparations and be ready for the inevitable changes by planting weather-resistant crops and developing shoreline taking into account future seas level rises.
Mass balance atmospheric circulation
Many think it is already too late to halt the onset of global warming. It has already happened and makes more sense to learn to live its consequences. John Holdren, a climate expert at Harvard, told the New York Times, “We basically have three choices—mitigation, adaption and suffering. We’re going to do some of each. The question is what the mix is going to be. The more mitigation we do, the less adaption will be required and the less suffering there will be.”
Some scientists predict major shortages of food and water and dislocations of large number of people occurring because of global warming in relatively short periods of time. Generals and admirals in war colleges are already preparing for such events and hostilities. Conflicts, even wars, could occur as a result from such events. Syria-Turkey, India-Pakistan and Greece-Macedonia are seen as potential trouble spots.
If the burning of fossil fuels was stopped today, by some estimates, it would take about 100,000 years for the all the carbon dioxide created already by man to vanish from the atmosphere—with much of it ending up on the bottom of the sea in deposits that will eventually become limestone.
Fractional Risk Attribution
Climatologists for the most part have been reluctant to attribute single events of extreme weather to climate change. Usually what they say is that extreme events are getting more likely as the amount of greenhouse gases in the atmosphere rises but tactfully hold back from casting any blame. Sharon Begley wrote in Newsweek, “Finally, climate scientists see a way to stop being so wishy-washy and start assigning blame, through a technique called “fractional risk attribution.” This technique uses mathematical models of how the atmosphere would work if we had not goosed carbon dioxide to 389 ppm (from 278 before the Industrial Revolution), plus data about ancient (“paleo”) climates and historical (more recent) weather. The idea is to calculate how many times an extreme event should have occurred absent human interference, explains climate scientist Ben Santer of Lawrence Livermore National Lab, and the probability of the same extreme event in today’s greenhouse-forced atmosphere. Result: putting numbers on extreme weather. [Source: Sharon Begley, Newsweek, November 27, 2010]
In their biggest success, climate scientists led by Peter Stott of the British Met Office analyzed the 2003 European heat wave, when the mercury rose higher than at any time since the introduction of weather instruments (1851), and probably since at least 1500. After plugging in historical and paleo data, and working out climate patterns in a hypothetical world without a human-caused greenhouse effect, they conclude that our meddling was 75 percent to blame for the heat wave. Put another way, we more than doubled the chance that it would happen, and it’s twice as likely to be human-caused than natural. That’s one beat shy of “Yes, we did it,” but better than “There’s no way to tell.”
Scientists are now applying the technique to other extreme weather, especially deluges and droughts. They have reason to be optimistic. One of the signal successes of climate science has been identifying the “fingerprints” of the culprits behind rising temperatures, fierce storms, and other signs that a 10,000-year-old climate regime has been knocked for a loop. Fingerprinting has shown that the rise in global temps follows the pattern you’d expect from the greenhouse effect and not an increase in the sun’s output, for instance. A hotter sun would heat the upper atmosphere more than the lower, but in fact the upper layers have cooled while the lower have warmed, Santer explains. Fingerprinting has also nailed the greenhouse effect for warming the oceans. Natural forces such as El Niño warm some seas and cool others, but every major ocean is hotter than in the 1950s. Similar analyses have been done for today’s extreme rainfall patterns (drought followed by deluge, not precipitation spread out evenly) and the retreat of arctic sea ice. “Natural causes alone can’t explain any of these,” Santer says. “You need a large human contribution.”
Image Sources: World Meteorological Organization; National Oceanic and Atmospheric Administration (NOAA), Wikimedia Commons
World Meteorological Organization; National Oceanic and Atmospheric Administration (NOAA), Text Sources: New York Times, Washington Post, Los Angeles Times, Times of London, Yomiuri Shimbun, The Guardian, National Geographic, The New Yorker, Time, Newsweek, Reuters, AP, Lonely Planet Guides, Compton’s Encyclopedia and various books and other publications.
© 2008 Jeffrey Hays
Last updated January 2012