Death of a Great Planet
By: Hilary Battey
For centuries, scientists have pondered the fate of our planet. Catastrophic events have occurred in the past and will very likely happen again. How and when will “the end” for the earth occur? We explore the issue from the perspectives of our own backyard, our planet, and our place in the universe.
Nation: Camping or Catastrophe
Let’s say you’re with camping with the family in Yellowstone National Park. You could be perched uncomfortably near the source of destruction for our country.
The park is home to the Yellowstone Caldera—a potential supervolcano. Calderas form when the land surrounding a volcano collapses after an eruption. The earth’s magma continues to percolate, however. When magma rises to the crust from hotspots below but is unable to break through fissures on the surface, a supervolcano can occur. Mounting pressure can result in a massive eruption, spewing magma and other ejected debris more than 60 miles from the point of origin.
“Such an eruption would devastate a large part of the continental U.S,” says Peter Hudleston, professor of structural geology at the University of Minnesota.
Enormous ash clouds produced by supervolcanoes pose an even bigger threat. The ash can block the sun, causing frigid temperatures and wiping out millions of species. “A Yellowstone eruption would affect the climate, probably producing global cooling by putting large amounts of radiation-reflecting ash in the upper atmosphere,” Hudleston says. “It’s possible that humans might not survive a really huge event,” but Hudleston thinks the odds of life continuing on are good. “It’s unlikely that any foreseeable volcanic event would completely wipe out life on Earth, as the past events we know about did not do that.”
World: Running a Fever
Global warming has long been considered a potential cause of death for our planet. “Our best understanding is that we have already locked in major consequences for the way life is currently organized on the earth,” says professor Lawrence Rudnick, an observational astrophysicist at the U of M. For the last 12 years, Rudnick has taught a “Cosmic Catastrophes” course, which explores threats to our planet and its inhabitants.
“My own fascination is with the key role played by catastrophic events for the evolution of life on earth,” he says. Each major incident—from the formation of the moon to the extinction of dinosaurs to man-made catastrophes—has had bearing on how we live. Those life-altering events continue. For example, he cites today’s global warming and habitat destruction as key contributors to species extinction. Global warming changes precipitation patterns, which can cause devastating storms and hurricanes as the oceans rise in temperature, as well as the loss of crops and livestock from widespread drought. In fact, New York City Mayor Michael Bloomberg recently went on record blaming global warming for Hurricane Sandy.
Though still controversial, a growing body of scientific research seems to indicate real and substantive changes to the climate.
The American Geophysical Union claims the average surface temperatures have increased by about 0.6°C from 1956 to 2006. And during a 12-year period from 1994 to 2006, 11 of those years were warmer than any others on record since 1850.
The United States Environmental Protection Agency has published similar data. Since 1901, surface temperatures in the United States have risen at an average rate of 0.13°F per decade across the lower 48 states. The globe’s average surface temperature has increased almost 1.5°F during the 20th century. Two-thirds of this warming has occurred since 1975.
On the ground evidence of global climate change comes in the form of diminished glaciers. Montana’s Glacier National Park is currently home to 25 glaciers, down from 27 in 2010 and 150 in 1910. This current trend is not looking promising for the remaining glaciers.
Cosmos: Crash, Bang, Boom?
The year 2036 could be a devastating one, according to a National Aeronautics and Space Administration study. An asteroid named Apophis is predicted to pass near earth on April 13, 2029 (yes, this is a Friday). The earth will essentially deflect the asteroid, but not without effects: the near miss could change our orbit. Seven years later, when Apophis next heads toward our planet, it could collide with cataclysmic results.
According to Rudnick, an asteroid must measure 50 to 100 km in size in order to wreak catastrophic destruction. NASA indicates that Apophis is only 240 m, or .270 km in size. Rudnick says at its current size, Apophis could inflict regional damage but probably would not produce global implications.
Some scientists deem the probability of such a collision to be unlikely, while others scientists are seeking governmental assistance to prepare for this scenario. In 2006, experts on near-earth objects met in London to discuss the required technology necessary to deflect Apophis. Ideas ranged from rockets to satellites designed to nudge away any asteroid on a crash course with our little piece of the universe.
Whether earth’s end comes from within, by human interference or from outer space, one thing is certain—the planet’s health and well-being is inexorably tied to our own. There is no real way of knowing how our blue-and-green home may die, but like so many things, living with this uncertainty is simply part of life.