Global Warming? Compelling changes grip the Arctic

23 October 2007 | 04:57 Code : 15730 Geoscience events
Sharks are showing up in Alaskan waters, 124 glaciers have disappeared....

  Sharks are showing up in Alaskan waters, 124 glaciers have disappeared from the Montana landscape since 1850 and North Dakota has lost 10 percent of its annual precipitation in the past 100 years.Scientists are predicting that the entire Arctic Ocean could have an ice-free summer surface for the first time ever by 2050, which has touched off debate in Florida about a shrinking coastline should Arctic ice continue to melt.North Dakota’s average temperature has risen 2 degrees Fahrenheit in 100 years, while Fargo’s average is up almost 9 degrees. Snowfall in Montana has decreased nearly 22 percent since 1950 and for the first time in history, purple loosestrife, an invasive plant that grows naturally around potholes, has been discovered in Alaska’s interior wetlands.These are all red flags that global warming is taking place, according to Deborah Williams, a professor and founder of Alaska Conservation Solutions, an environmental agency in Anchorage aimed at bringing awareness to this phenomenon in Alaska and the rest of the nation.Eighty-one percent of Alaska residents are convinced global warming is happening and 71 percent believe it has become a serious problem, not only for their state, but for others including North Dakota and Montana. Williams is one of them. There’s a lower percentage of North Dakota residents who believe global warming is a problem. Nonetheless, it represents an issue that must be confronted, according to Williams.“I truly believe that global warming represents the single greatest threat to our two great, least populated and wonderful states,” Williams said. “North Dakota and Alaska have many commonalities, including huge costs associated with global warming and great renewable energy opportunities.”There’s been a lot of general information about global warming, so much so that many people are no longer taking a close enough look at it, according to Williams. Critics have suggested global warming is merely speculation by scientists who don’t have enough data to complete their theses, while others claim global warming is something former vice president Al Gore made up to bring attention to himself.The reality is, catastrophic events are telling a different story from the Arctic Ocean to the Gulf of Mexico. Violent storms have bashed parts of the United States in recent years, including Hurricane Katrina in August 2005. Severe flooding hampered America’s Heartland in the 1990s, including North Dakota, Iowa and Missouri, while the average temperature in Alaska has risen 4 degrees since it became a state in January 1959.Independently, David Sauchyn has been studying climate change at the University of Regina in Saskatchewan since October 2001. While numerous theories have surfaced about western Canada, the geography professor’s most compelling research indicates the three prairie provinces of Manitoba, Saskatchewan and Alberta are becoming slightly warmer and much drier. Alaska’s vulnerability is apparent, especially in interior villages, primarily because the atmosphere is thinner in the Arctic, according to Williams, and changes happen faster and are often times more dramatic than in the continental United States. She said communities above the Arctic Circle like Kotzebue, Barrow and Prudhoe Bay have seen melting sea ice and fewer snow days, down to as few as 50 in a year. Nome, just south of the Arctic Circle, has a similar fate with a rising and eroding coastline and warmer summer and autumn temperatures.Alaska is just the “tip of the iceberg” and is warming faster than most of us want to believe, according to Gerd Wendler, who is with the Geophysical Institute at the University of Fairbanks. One statistic that may come as a surprise to most people is that Fairbanks, located at 64 degrees north latitude, now has an average frost-free period of 115 days annually, according to Wendler. That’s up from an 80-day frost-free growing season when records were first kept in the early 1900s. North Dakota’s average frost-free period is arguably just 13 days longer.Alaska is at the forefront of global warming because many scientists believe what is happening in Alaska today will be happening in the Lower 48 tomorrow. “Coastal erosion has accelerated,” Wendler said. “This is a result of less sea ice, especially in the fall. And due to the absence of ice, increased wave activity accelerates erosion.”According to Wendler, melting permafrost also has to be considered as part of the problem. He said it’s of little importance to the North Slope because it is cold enough there to sustain permafrost. However, in interior Alaska, where the mean annual temperatures are closing in on the melting point, road and airport runway upkeep is becoming expensive.Like his Alaska counterparts, Will Gosnold is concerned about global warming and its implications on the Earth and future generations. Gosnold is the chair of the University of North Dakota’s department of geology and geological engineering in Grand Forks. He said there are actually two causes of global warming: One is natural and the other is related to human activity.For instance, throughout time there have been precipitation and temperature cycles, according to Gosnold. He said the precession, or wobble, of the Earth’s axis changes over a 23,000-year period. Earth’s tilt changes every 41,000 years, and every 100,000 years the eccentricity of the Earth’s orbit changes. Eccentricity is described as the varied distance Earth travels around the sun.“Together, these cycles cause slight changes in the amount of radiation falling on the planet,” Gosnold said. “These slight changes over time cause shifts in climate.”But more important are forced factors, according to Gosnold, which are those affecting atmospheric composition.“We humans have increased the atmospheric content of greenhouse gases, primarily carbon dioxide, or CO2, by burning fossil fuels to a point where the heat balance of the planet has changed,” Gosnold said. “The amount of CO2 in the atmosphere has increased by 27 percent since the Industrial Revolution and the increase is a consequence of burning fossil fuel.”Residually, water has a stronger effect than carbon dioxide and that leads to a serious feedback problem, according to Gosnold. He said global warming driven by all greenhouse gases has increased evaporation rates, and the amount of water in the atmosphere continues increasing.Internal combustion engines are major contributors of global warming and Americans are the world’s largest consumers of fossil fuels, Gosnold said. More than half of the 22 million barrels of oil consumed daily in the United States are used in personal transportation. Thus, U.S. carbon dioxide emissions dwarf those in China, the next nearest CO2 polluter. But that, too, has Gosnold concerned.“Now, the major contributor to global greenhouse gases turns out to be the Third World,” Gosnold said. “China and India are starting to make an impact with its huge populations and growing demand for oil.”On the other hand, he said, European nations have actually reduced its emissions since 1990 because its governments have taken a proactive role to reduce fossil fuel emissions, notably in England, Germany and Italy.Because of changes in climate and precipitation, Gosnold anticipates there will be stronger storms, such as Hurricane Katrina, which struck New Orleans and the Gulf Coast in August 2005. “Longer term predictions are that we’ll see a rise in the level of the oceans, maybe by as much as 23 feet,” Gosnold said. “It’s uncertain how long the rise will take, but if some predictions on the rapid decay of the polar ice caps are correct, it could occur by the end of this century.”Earth’s average temperature might actually be warmer than it is today, if not for a human convenience that has somewhat stymied the climb in temperature. Gosnold said aerosols are causing fewer sun rays to actually reach the Earth, a phenomenon he calls global dimming. Various types of particles are reflecting solar energy back into space, so the amount of sunlight reaching the ground is 30 percent less today than it was in 1950.“The culprit is atmospheric pollution due to human activity,” Gosnold said. “This may explain why climate researchers have had difficulty matching models of greenhouse warming with the actual rate of warming. The models did not include the reduction in solar radiation at ground level. Global dimming has retarded the rate of warming, and this tells us that without the aerosol pollution, Earth would have been warming at an even faster pace.”

tags: QAZVIN

Your Comment :