Monday, October 15, 2007

The ELE Series—Global Warming

On October 15th, bloggers around the web will unite to put a single important issue on everyone’s mind—the environment. Every blogger will post about the environment in their own way and relating to their own topic. Our aim is to get everyone talking towards a better future.

Future generations may well have occasion to ask themselves, "What were our parents thinking? Why didn't they wake up when they had a chance?" We have to hear that question from them, now. —Al Gore, An Inconvenient Truth

The latest report on climate change to the United Nations says global warming is happening and that humans are "very likely" responsible for it. CO2 levels, already the highest they've been in over 600,000 years, are still going up, too. Because temperature fluctuations appear to have some correlation with CO2 levels, the earth seems to be much more fragile than we were all taught in grade school and at this rate, if temperatures continue to increase, the Greenland and polar ice caps will almost certainly melt.

In fact, it looks like the ice is already melting at an alarming rate:

Sir Richard Attenborough believes humans are responsible:

And in An Inconvenient Truth, Al Gore presented a graph charting data taken from polar ice samples spanning 600,000 years:

The bottom line on the chart above is the earth's temperature over 600,000 years, and the line above represents CO2 emissions. While there is no scientific proof per se that CO2 emissions are the cause of global temperatures (CO2 emissions might be the effect of a cause which also affects global temperatures), this data is compelling. The vertical red line after the dot is where CO2 emissions are predicted on rising to in the coming years; the line is completely vertical because its rate of increase is so high relative to the chart's timeline that it cannot be seen. Thus, if you accept the assumption that CO2 emissions are the central cause of global warming, you can imagine what impact that level of CO2 emissions would have on global warmth.

For those who thinks global warming is still fiction, consider this news clipping from January 31, 2007 (and pay special heed to the boldface):
The UN Intergovernmental Panel on Climate Change is due to release a report in Paris on Friday entitled Climate Change 2007 in which 2,500 scientists from 130 countries unequivocally state that the current trend towards potentially catastrophic global warming has been induced by human activity, which began with the dramatic increase in fossil fuel use during the Industrial Revolution of the mid-19th century....

The report is not without its critics in the scientific community. One senior British climate expert quoted in The Observer warned that the report’s predictions are relatively rosy, given its painstaking consensus process: “The really chilling thing about the IPCC report is that it is the work of several thousand climate experts who have widely differing views about how greenhouse gases will have their effect. Each paragraph of this report was therefore argued over and scrutinized intensely. Only points that were considered indisputable survived this process. This is a very conservative document—that's what makes it so scary.” —Source

Forget for a moment that Al Gore recently won the Nobel Peace Price for his work on raising awareness about climate change. Instead, picture 2,500 scientists across 130 countries co-authoring a document they can all agree on. They may disagree about many things in this document, but "only points that were considered indisputable survived this process." What brand of skeptic can comfortably refute that?

Even more evidence for the naysayers—on December 29, 2006, a Canadian ice shelf the size of 11,000 football fields was reported to have broken away from the mainland:
Ancient ice shelf breaks free from Canadian Arctic
POSTED: 11:31 a.m. EST, December 29, 2006

• Scientist: "Disturbing event" shows "we are crossing climate thresholds"
• Researchers using satellite images discovered 2005 event
• Collapse picked up by earthquake monitors 155 miles away

TORONTO, Ontario (AP)—A giant ice shelf the size of 11,000 football fields has snapped free from Canada's Arctic, scientists said.

The mass of ice broke clear 16 months ago from the coast of Ellesmere Island, about 800 kilometers (497 miles) south of the North Pole, but no one was present to see it in Canada's remote north.

Scientists using satellite images later noticed that it became a newly formed ice island in just an hour and left a trail of icy boulders floating in its wake. (Watch the satellite images that clued in ice watchers)

Warwick Vincent of Laval University, who studies Arctic conditions, traveled to the newly formed ice island and could not believe what he saw.

"This is a dramatic and disturbing event. It shows that we are losing remarkable features of the Canadian North that have been in place for many thousands of years. We are crossing climate thresholds, and these may signal the onset of accelerated change ahead," Vincent said Thursday.

In 10 years of working in the region he has never seen such a dramatic loss of sea ice, he said.

The collapse was so powerful that earthquake monitors 250 kilometers (155 miles) away picked up tremors from it.

The Ayles Ice Shelf, roughly 66 square kilometers (41 square miles) in area, was one of six major ice shelves remaining in Canada's Arctic.

Scientists say it is the largest event of its kind in Canada in 30 years and point their fingers at climate change as a major contributing factor.

"It is consistent with climate change," Vincent said, adding that the remaining ice shelves are 90 percent smaller than when they were first discovered in 1906.

"We aren't able to connect all of the dots... but unusually warm temperatures definitely played a major role."

Laurie Weir, who monitors ice conditions for the Canadian Ice Service, was poring over satellite images in 2005 when she noticed that the shelf had split and separated.

Weir notified Luke Copland, head of the new global ice lab at the University of Ottawa, who initiated an effort to find out what happened.

Using U.S. and Canadian satellite images, as well as data from seismic monitors, Copland discovered that the ice shelf collapsed in the early afternoon of August 13, 2005.

"What surprised us was how quickly it happened," Copland said. "It's pretty alarming.

"Even 10 years ago scientists assumed that when global warming changes occur that it would happen gradually so that perhaps we expected these ice shelves just to melt away quite slowly, but the big surprise is that for one they are going, but secondly that when they do go, they just go suddenly, it's all at once, in a span of an hour."

Within days, the floating ice shelf had drifted a few miles (kilometers) offshore. It traveled west for 50 kilometers (31 miles) until it finally froze into the sea ice in the early winter.

The Canadian ice shelves are packed with ancient ice that dates back over 3,000 years. They float on the sea but are connected to land.

Derek Mueller, a polar researcher with Vincent's team, said the ice shelves get weaker and weaker as the temperature rises. He visited Ellesmere's Ward Hunt Ice Shelf in 2002 and noticed it had cracked in half.

"We're losing our ice shelves, and this a feature of the landscape that is in danger of disappearing altogether from Canada," Mueller said. "In the global perspective Antarctica has many ice shelves bigger than this one, but then there is the idea that these are indicators of climate change."

The spring thaw may bring another concern as the warming temperatures could release the ice shelf from its Arctic grip. Prevailing winds could then send the ice island southwards, deep into the Beaufort Sea.

"Over the next few years this ice island could drift into populated shipping routes," Weir said. "There's significant oil and gas development in this region as well, so we'll have to keep monitoring its location over the next few years."

Here's what How Stuff Works says about it:
The main ice covered landmass is Antarctica at the South Pole, with about 90 percent of the world's ice (and 70 percent of its fresh water). Antarctica is covered with ice an average of 2,133 meters (7,000 feet) thick. If all of the Antarctic ice melted, sea levels around the world would rise about 61 meters (200 feet). But the average temperature in Antarctica is -37°C, so the ice there is in no danger of melting. In fact in most parts of the continent it never gets above freezing.

There is a significant amount of ice covering Greenland, which would add another 7 meters (20 feet) to the oceans if it melted. Because Greenland is closer to the equator than Antarctica, the temperatures there are higher, so the ice is more likely to melt.

But there might be a less dramatic reason than polar ice melting for the higher ocean level—the higher temperature of the water. Water is most dense at 4 degrees Celsius. Above and below this temperature, the density of water decreases (the same weight of water occupies a bigger space). So as the overall temperature of the water increases it naturally expands a little bit making the oceans rise.

In 1995, the International Panel on Climate Change issued a report which contained various projections of the sea level change by the year 2100. They estimate that the sea will rise 50 centimeters (20 inches) with the lowest estimates at 15 centimeters (6 inches) and the highest at 95 centimeters (37 inches). The rise will come from thermal expansion of the ocean and from melting glaciers and ice sheets. Twenty inches is no small amount—it could have a big effect on coastal cities, especially during storms. — Source.

If global warming accelerates to the worst-case scenario, i.e., if all the world's ice totally melts into the oceans, ocean levels will rise a maximum of 68 meters (220 feet), far less than portrayed in the film Waterworld, but much closer to A.I.. If you assume about 12.5 feet per building story, 220 feet is a little over 17.5 stories, which means my old 17th floor residence in the 20 floor New York City apartment building where I grew up would be completely underwater.

Technically speaking, global warming isn't a definitive extinction level event for humans, but it comes very close. If ocean levels rise too quickly—say over a century, rather then two centuries—mass migrations could spark a crippling economic implosion. Humans adapt, and while they're on the cusp of great technological discoveries, adjusting to an aquatic world by genetically splicing gills into our DNA will likely be overkill: if everything melts, there will still be land to live on. Thus, humans will still be able to to mine the necessary resources to colonize other planets and escape any comets coming from the Oort cloud.

Even so, you have to appreciate the cosmic irony that the accidental warming of our own planet—which could potentially bring about our own destruction here on Earth—may also be the most useful tool we learn to warm up and colonize Mars.

Further reading: An overview of information related to global warming compiled by Texas A&M University's Laboratory for Applied Biotelemetry & Biotechnology.

This is Part 5 of The ELE Series, a list of articles exploring the nature of extinction level events, or E.L.E's. You can read previous articles in the series by clicking on these links:
The ELE Series—An Overview
The ELE Series—Measuring Our Future
The ELE Series—Comets & The Oort Cloud
The ELE Series—Outbreak

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