No Need for Tears for Cryosphere

No Need for Tears for Cryosphere
November 23, 2013

Isaac Orr


The first time I heard about the potential consequences of manmade global warming, my mind immediately raced to one terrible conclusion: This could make it much harder to build snow forts.

I was in fourth-grade science class at the time.

As a kid, I was convinced carbon dioxide (CO2) emissions were going to send the planet into a tailspin. I remember sometimes holding my breath until I could run outside and exhale directly on a plant (because I learned they convert CO2 directly into oxygen) so the polar bears would be OK.

I didn’t know it at the time, but I was worried about the cryosphere. For those who are wondering, the cryosphere is those parts of the world where it is cold enough that water is present in solid form as snow or ice in glaciers, icecaps, and sea ice.

Frozen water accounts for only 3 percent of the global water supply, but it comprises nearly 75 percent of the fresh water on Earth, with more than 99 percent of this frozen water located in the Greenland and Antarctic ice sheets.

If all of that snow and ice were to melt, it would raise the sea level by approximately 220 feet, which would be bad news considering 39 percent of the U.S. population lives in counties directly located on the shoreline and coastal populations have grown by 45 percent since 1970.

Fortunately, that’s not likely to happen any time soon. A new report by the Nongovernmental International Panel on Climate Change (NIPCC) suggests the situation is not quite as dire as I had imagined in the fourth grade.

According to Climate Change Reconsidered-II: Physical Science, Chapter Five: The Cryosphere, although the West Antarctic Ice Sheet (WAIS), which represents 10 percent of Antarctic ice, has shown some indications of melting, the East Antarctic Ice Sheet (EAIS), which comprises the remaining 90 percent of Antarctic continental ice, has been growing at a rate that negates the melting of the WAIS.

Between 1979 and 2008, East Antarctic sea ice increased in area by about half a million square kilometers, increasing 2–3 percent during the spring and winter seasons and 5–7 percent during summer. This growth has served to “counterbalance”  the recent trend toward decreasing Arctic sea ice that has occurred since 1979.

These trends, coupled with the fact that the climate has not warmed significantly since 1998, are part of the reason sea levels have not risen as fast as predicted by the Intergovernmental Panel on Climate Change (IPCC).

In addition to warehousing approximately two-thirds of the fresh water on Earth, the Greenland and Antarctic ice sheets provide something else: a remarkable layered ice record of past climactic change back to 120,000 and almost 1 million years ago, respectively.

Changing oxygen isotope ratios in the ice act as a proxy for ancient air temperature change, enabling scientists to estimate the amount of atmospheric CO2 (carbon dioxide) and CH4 (methane) in the past.

Scientists have long understood there is a relationship between rising global temperatures and elevated levels of atmospheric CO2, but what has been less clear is which of these phenomena drives the other.

The new NIPCC report, citing evidence gathered by examining Antarctic and Greenland ice cores, challenges the notion that climate change is driven primarily by human greenhouse gas emissions. It cites peer-reviewed research showing changes in ancient CO2 lag equivalent changes in temperature by up to a thousand years. That means increases in CO2 cannot be the cause of the warming documented in these ice cores because the changes in temperature happen before the changes in CO2 levels.

For those who seriously believe in considering all sides of an issue before making a decision, these findings are bound to serve as a valuable (and controversial) resource. They certainly merit further investigation.

We will have a lot of time to wade through the research and come to our own conclusions, because the debate on climate change is unlikely to end soon.

Luckily, neither is the cryosphere.


Isaac Orr
