2. What is Global Warming?

Archives of Past Articles for Chapter 2

2009 October 16. Arctic To Be Ice-Free In Summer In 20 Years. By Peter Griffiths, Planet Ark. Excerpt: LONDON - Global warming will leave the Arctic Ocean ice-free during the summer within 20 years, raising sea levels and harming wildlife such as seals and polar bears, a leading British polar scientist said on Thursday.
Peter Wadhams, professor of ocean physics at the University of Cambridge, said much of the melting will take place within a decade, although the winter ice will stay for hundreds of years.
The changes will mean the top of the Earth will appear blue rather than white when photographed from space and ships will have a new sea route north of Russia.
Scientists say evidence of melting Arctic ice is one of the clearest signs of global warming and it should send a warning to world leaders meeting in Copenhagen in December for U.N. talks on a new climate treaty....
Dr Martin Sommerkorn, from the environmental charity WWF's Arctic program, which worked on the survey, said the predicted loss of ice could have wide-reaching affects around the world.
"The Arctic Sea ice holds a central position in our Earth's climate system. Take it out of the equation and we are left with a dramatically warmer world," he said.
"This could lead to flooding affecting one-quarter of the world's population, substantial increases in greenhouse gas emissions .... and extreme global weather changes."...

2009 May 4. Climate Change: Halving Carbon Dioxide Emissions By 2050 Could Stabilize Global Warming. ScienceDaily. Excerpt: If CO2 emissions are halved by 2050 compared to 1990, global warming can be stabilised below two degrees. This is shown by two studies by a co-operation of German, Swiss and British researchers in the journal Nature.
To contain global warming, and its risks and consequences, warming compared to pre-industrial times (pre 1900) should not exceed two degrees Celsius. Although, according to the reports of the Intergovernmental Panel on Climate Change (IPCC), there is no specific temperature threshold for dangerous climate changes, and the negative effects are gradually increasing, over one hundred countries have adopted this “2°C target”. Scientists have used a new probability model to calculate how much CO2 our atmosphere tolerates under these target specifications. ...From 2000 to 2050, a maximum of 1000 billion tonnes of CO2 may be emitted into the atmosphere. Roughly speaking, today, around one third of this wad has already been shot.
“The behaviour of CO2 in the atmosphere is best described as a full bathtub,” says Reo Knutti, professor at the Institute for Atmosphere and Climate at ETH Zurich, and co-author of one of the two studies. The inflow of the bathtub is large, but the drainage is small. The CO2 emissions are increasing every year, but the CO2 is only removed from the atmosphere very slowly. To not let the bathtub overflow, the inflow must thus be stopped early enough. “It is wrong to believe that the temperature will remain constant with constant emissions,” says Knutti....

2008 May 1. In a New Climate Model, Short-Term Cooling in a Warmer World. By ANDREW C. REVKIN, NY Times. Excerpt: After decades of research that sought, and found, evidence of a human influence on the earth's climate, climatologists are beginning to shift to a new and similarly daunting enterprise: creating decade-long forecasts for climate, just as meteorologists routinely generate weeklong forecasts for weather.
One of the first attempts to look ahead a decade, using computer simulations and measurements of ocean temperatures, predicts a slight cooling of Europe and North America, probably related to shifting currents and patterns in the oceans.
The team ... from two German ocean and climate research centers, acknowledged that it was a preliminary effort. But in a short paper ... in the May 1 issue of ... Nature, they said their modeling method was able to reasonably replicate climate patterns in those regions in recent decades, providing some confidence in their prediction for the next one.
The authors stressed that the pause in warming represented only a temporary blunting of the centuries of rising temperatures that scientists have projected if carbon dioxide and other heat-trapping gases continue accumulating in the atmosphere.
"We're learning that internal climate variability is important and can mask the effects of human-induced global change," said the paper's lead author, Noel Keenlyside of the Leibniz Institute of Marine Sciences in Kiel, Germany. "In the end this gives more confidence in the long-term projections."
...Other researchers, including NASA scientists at the Jet Propulsion Laboratory in Pasadena, Calif., reported ... that a slowly fluctuating oscillation in Pacific Ocean temperatures had shifted into its cool phase, a condition that is also thought to exert an overall temporary cooling of the climate.
These natural variations can also amplify warming, and that is likely to happen in future decades on and off as well, experts say. ...It should also help the public and policy makers understand that a cool phase does not mean the overall theory of human-driven warming is flawed, Dr. Trenberth said.
"Too many think global warming means monotonic relentless warming everywhere year after year," Dr. Trenberth said. "It does not happen that way."

1 October 2007. NASA EXAMINES ARCTIC SEA ICE CHANGES LEADING TO RECORD LOW IN 2007. Excerpt: A new NASA-led study found a 23-percent loss in the extent of the Arctic's thick, year-round sea ice cover during the past two winters. ...A team led by Son Nghiem of NASA's Jet Propulsion Laboratory, Pasadena, Calif., studied trends in Arctic perennial ice cover by combining data from NASA's Quick Scatterometer (QuikScat) satellite with a computing model based on observations of sea ice drift from the International Arctic Buoy Programme. QuikScat can identify and map different classes of sea ice, including older, thicker perennial ice and younger, thinner seasonal ice. Between winter 2005 and winter 2007, the perennial ice shrunk by an area the size of Texas and California combined.
...Nghiem said the rapid decline in winter perennial ice the past two years was caused by unusual winds. "Unusual atmospheric conditions set up wind patterns that compressed the sea ice, loaded it into the Transpolar Drift Stream and then sped its flow out of the Arctic," he said. When that sea ice reached lower latitudes, it rapidly melted in the warmer waters.
"The winds causing this trend in ice reduction were set up by an unusual pattern of atmospheric pressure that began at the beginning of this century," Nghiem said.
...For more information, visit:
http://winds.jpl.nasa.gov/missions/quikscat/index.cfm

17 May 2007. Polar ocean 'soaking up less CO2'. By Paul Rincon Science reporter, BBC News. Excerpt: The Southern Ocean is an important natural carbon sink.... One of Earth's most important absorbers of carbon dioxide (CO2) is failing to soak up as much of the greenhouse gas as it was expected to, scientists say. The decline of Antarctica's Southern Ocean carbon "sink" - or reservoir - means that atmospheric CO2 levels may be higher in future than predicted....There are two major natural carbon sinks: the oceans and the land "biosphere". They are equivalent in size, each absorbing a quarter of all CO2 emissions. The Southern Ocean is thought to account for about 15% of all carbon sinks....Lead researcher Corinne Le Quere [University of East Anglia] and colleagues collected atmospheric CO2 data from 11 stations in the Southern Ocean and 40 stations across the globe. ..."Ever since observations started in 1981, we see that the sinks have not increased [in their absorption of CO2]," Corinne LeQuere told the BBC's Science in Action programme. "They have remained the same as they were 24 years ago even though the emissions have risen by 40%." The cause of the decline in the Southern Ocean sink, the researchers explain, is a rise in windiness since 1958. ...Oceans store much of their CO2 in deep waters. But, explained Dr Le Quere, "as the winds increase, the water in the ocean mixes more". The British Antarctic Survey (BAS) scientist added: "The CO2 that would normally be in the deep ocean and would just stay there instead gets brought up to the surface and outgasses to the atmosphere." The ocean surface becomes saturated with CO2 and cannot take up any more from the atmosphere.....

9 April 2007. Foundation to Offer $100 Million to Deal With Global Warming. By STEVE LOHR. NY Times. Excerpt: The Doris Duke Charitable Foundation is creating a $100 million program to support research intended to encourage policies aimed at reducing the threat of global warming. The foundation's climate change project, which is being announced today, comes amid an increasing political push for legislation to curb emissions of carbon dioxide from burning fossil fuels like coal, natural gas and gasoline. Several bills that would set mandatory restrictions on emissions of carbon dioxide, the main greenhouse gas, have been introduced in Congress. Other clean-energy bills under consideration are intended to increase the use of renewable energy and promote energy efficiency. Most of the presidential hopefuls for 2008 have proposals to deal with climate change. ...Homes, offices and power plants, Mr. Bowman noted, often last for 50 or 60 years. "We have to do everything we can to make sure we deploy the most efficient technologies that we can over the next five and ten years to prevent having an economy that is locked in to a really inefficient infrastructure," he said....

19 March 2007. NASA FINDS SUN-CLIMATE CONNECTION IN OLD NILE RECORDS. Earth Observatory. Long-term climate records are a key to understanding how Earth's climate changed in the past and how it may change in the future. Direct measurements of light energy emitted by the sun, taken by satellites and other modern scientific techniques, suggest variations in the sun's activity influence Earth's long-term climate. However, there were no measured climate records of this type until the relatively recent scientific past. ...a group of NASA and university scientists has found a convincing link between long-term solar and climate variability in a unique and unexpected source: directly measured ancient water level records of the Nile, Earth's longest river. Alexander Ruzmaikin and Joan Feynman of NASA's Jet Propulsion Laboratory, ... together with Dr. Yuk Yung of the California Institute of Technology, ... have analyzed Egyptian records of annual Nile water levels collected between 622 and 1470 A.D. at Rawdah Island in Cairo. These records were then compared to another well-documented human record from the same time period: observations of the number of auroras reported per decade in the Northern Hemisphere. ...They are an excellent means of tracking variations in the sun's activity. Feynman said ... "Since the time of the pharaohs, the water levels of the Nile were accurately measured, since they were critically important for agriculture and the preservation of temples in Egypt," ...The researchers found some clear links between the sun's activity and climate variations. The Nile water levels and aurora records had two somewhat regularly occurring variations in common - one with a period of about 88 years and the second with a period of about 200 years. ... what causes these cyclical links between solar variability and the Nile? The authors suggest that variations in the sun's ultraviolet energy cause adjustments in a climate pattern called the Northern Annular Mode, which affects climate in the atmosphere of the Northern Hemisphere during the winter. At sea level, this mode becomes the North Atlantic Oscillation, a large-scale seesaw in atmospheric mass that affects how air circulates over the Atlantic Ocean.

March 2007. The Discovery of Global Warming. By Spencer Weart. Extensive web pages on history of the discovery of global warming based on book published in June 2006. Hosted at American Institute of Physics website: http://www.aip.org/.

September 2006. Global Warming - Vanishing Glaciers. AAA Via Magazine. Climate change is starting to make its mark on some popular travel spots. The ice fields of the West are especially feeling the heat. By Deborah Franklin. ... visitors to Alaska have begun to notice ... An estimated 95 percent of the state's glaciers, like most around the world, are receding. Where a few decades ago there were blankets of ice, now hundreds of feet or even miles of bare rock are exposed. ...For nonscientists, the most compelling part of Dan Fagre's research in Glacier National Park may be his album of photographs taken by tourists, a graphic record of glaciers melting across a century. Even before famed conservationist and ornithologist George Bird Grinnell proclaimed the northern Rockies the "crown of the continent" and urged Congress to establish the park in the early 1900s, the Great Northern Railway was delivering awestruck Easterners to the region's doorstep. ...By comparing the photographs those early hikers took with recent pictures taken at the same spots today, Fagre and his colleagues now have an amazingly rich record of climate change throughout the park. The transformation the images reveal is astounding: Sperry, Grinnell, Jackson, and other glaciers, now well on their way to becoming slushy snowfields and lakes, were once powerful symbols of might, as stirring as any Alaskan wall of ice today.

September 2006. Global Warming - Rising Tides. AAA Via Magazine, By Thomas Swick. ... Donald Flinn... was vice president of operations for Klondike Star Mineral Corporation in Whitehorse, Yukon Territory. "In winter it always used to go below minus 40. Now it rarely does. The glaciers are melting. There's the loss of the permafrost." ...Rarotonga is the largest of the 15 tiny land masses known as the Cook Islands, a self-governing nation in free association with New Zealand. ...Coral bleaching has been extensive, the result of stress caused by several factors: pollution (sewage and sediment run into the lagoons), natural predators (such as the crown- of-thorns starfish), cyclones (which damage the ocean side of the reefs), and rising sea temperatures. These warmer temperatures also cause water to expand, which inevitably leads to rising sea levels. This, coupled with additional runoff from the melting ice caps, is a volatile one-two punch for coastal areas. Some uninhabited islands in the nations of Tuvalu and Kiribati have already vanished. Even people on islands safe from submersion may find it difficult to live on them. In some places, salt water has intruded into groundwater supplies and residents have fled to higher ground....

17 July 2006. The Messenger. Technology Review. Excerpt: ...Jim Hansen may be the most respected climate scientist in the world. He's been director of NASA's premier climate research center, the Goddard Institute for Space Studies (GISS), for 25 years and a member of the National Academy of Sciences (NAS) for 10. And he more or less single-handedly turned global warming into an international issue one sweltering June day in 1988, when he told a group of reporters in a hearing room, just after testifying to a Senate committee, "It's time to stop waffling so much and say that the greenhouse effect is here and is affecting our climate now."

...An attempt by the Bush administration to silence him early this year also helped turn global warming into one of the biggest news stories of 2006. It began on December 6, 2005, when Hansen declared in a talk at the American Geophysical Union in San Francisco that if our rate of fossil fuel burning continues to grow, we will eventually transform Earth into "a different planet." He presented an analysis showing that existing technologies can significantly cut greenhouse emissions, and suggested that a global solution requires leadership by the United States.n On December 15, he and three colleagues posted a routine monthly analysis on the GISS website, summarizing data from thousands of weather stations around the globe. It showed that 2005 was coming in as the warmest year since the mid-1800s. He was interviewed about this by ABC News. ...He says he's been muzzled before -- during the Reagan and first Bush administrations -- but that in more than three decades as a government employee, he has seen nothing to equal the recent clampdown. He is angry, but he expresses his anger calmly.

...More than 20 years ago, Hansen also explained why global warming has lagged the greenhouse buildup. In 1985, he suggested that it should take between 50 and 100 years for the excess energy reaching the planetary surface to have its full effect on temperature, because the energy will first go to heating the oceans; only when they begin to warm will the atmosphere follow suit. Just last year, when studies demonstrating a global rise in ocean temperatures confirmed his thinking, Hansen began referring to the heating of the oceans as the "smoking gun" of global warming.

... In 1990, Hansen and Lacis showed that traditional air pollution has produced a mighty parasol effect. We send dust and aerosols into the air from tailpipes and smokestacks, by burning the wood and dung that provide heat and light to hundreds of millions of the world's very poor, and through slash-and-burn agriculture and other land use practices that have exposed vast tracts of dried-out, eroded soil to the blowing wind. The dimming of incident sunlight caused by reflection from these airborne particles now offsets about half the warming of the industrial age. To continue offsetting our growing greenhouse emissions, we would have to maintain the rapid growth of traditional, noxious air pollution. But the United States and Europe have begun controlling it, and the dismal air quality in Beijing and Mumbai is convincing the Chinese and Indians that they must, too.

...Hansen continues to believe we can forestall disaster. ...Though he warned that carbon dioxide emissions must be stabilized over the next few decades, he also suggested that significant progress could be made by reducing the emissions of other greenhouse gases, particularly methane and ozone.... ...growing emissions from coal-burning power plants and transportation posed the greatest threats. ... Hansen says that if we continue to increase greenhouse-gas emissions, temperatures will rise between 2 and 3 ¼C this century, making Earth as warm as it was three million years ago, when seas were between 15 and 35 meters higher than they are today....

23 June 2006. The World Is Hot. By THOMAS L. FRIEDMAN The New York Times. Excerpt: In a developing country like Peru, where many people live on the land and close to the edge, climate change is neither a hobby nor a question for debate. ...It's a daily reality, particularly for the residents in the spectacular Urubamba River Valley, the birthplace of Incan civilization. Watching the sun rise from atop the Incan ruins at Machu Picchu, you can look around 360 degrees and see Andean mountains everywhere. The highest of them were always described in the guidebooks as "snow capped." Today, they're more "snow frosted." They still have snow, but there is a lot of rock now showing through on many of them. If these trends continue, in a few years they'll just be described as "steely gray." The great Andean glaciers are melting, receding at about 100 meters a decade. ...Nearby, in the Sacred Valley of the Incas, Jose Ignacio Lambarri, who owns a 60-acre farm, is also feeling the heat. He grows giant white corn, with kernels that used to be as big as a quarter. This corn, which is exported to Spain and Japan, grows in this valley because of a unique combination of water, temperature, soil and sun. But four years ago, Mr. Lambarri told me, he started to notice something: "The water level is going down, and the temperature is going up." As a result, the giant corn kernels are not growing quite as large as they used to, new pests have started appearing, and there is no longer enough water to plant the terraces in the valley that date from Incan times. He also noticed that the snow line he had grown up looking at for 44 years was starting to recede, which was making relations with his fellow farmers more difficult. Every year they decide by committee how to divide up the water. Now, "every year the meetings get more heated, because there is less water to distribute and the same amount of land that needs it," he said. "I tell my wife the day that mountain loses its snow, we will have to move out of the valley."....

March 2006. Understanding and Responding to Climate Change - Highlights of National Academies Reports

24 January 2006. 2005 Was the Warmest Year in a Century. The year 2005 may have been the warmest year in a century, according to NASA scientists studying temperature data from around the world.

Archives of Past Articles for Chapter 2

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