Uni High Gargoyle Staff Blog

In light of the near-record low temperatures and heavy blizzards lately, many people are wondering, “What happened to global warming?” Aren’t we supposed to be having milder winters instead of blizzards and negative temperatures in mid-February? After all, excessive greenhouse gases emitted by cars and other man-made products prevent the sun’s heat from escaping the lower atmosphere, resulting in an increase in global temperature. It all makes sense, right?

Not necessarily. In fact, some suggest that global warming may just lead us into the next “Ice Age.” Yes, it sounds contradictory: warming, Ice Age. But for those of you who have seen the movie “The Day After Tomorrow” (as mentioned by Carl), you would know that global warming causes a shutdown of the Great Ocean Conveyor, unleashing furies of nature that completely bury New York under snow in just a few days. But just how much of a science fiction movie can become reality?

First of all, global warming can in fact slow down or put a stop to what is known as the Great Ocean Conveyor. This ocean current circulation is what accounts for the warm weathers of Western Europe and parts of North America.

Warm waters from the tropics are carried north by the Gulf Stream, cooling as it goes. By the time it reaches areas near Iceland and Labrador, it has turned cold and increased in salinity (due to evaporation). Since colder saltwater is denser than warmer freshwater, the water sinks to the bottom of the North Atlantic. More warm water from the equator replaces the sunken water and this circulation pattern, known as the Great Ocean Conveyor, is what brings warmth from the tropics to heat North America and Europe.

However, according to a report by NASA, the melting ice caps in the North Atlantic region are dumping excessive freshwater into the North Atlantic Ocean, interfering with this cycle. Since denser saltwater needs to sink to the bottom of the ocean in order to continue this circulation, the addition of freshwater may slow down or even stop the Great Ocean Conveyor.

The Ocean and Climate Change Institute reported that a disruption of the Great Ocean Conveyor is predicted to cool oceanic and atmospheric temperatures in the Northern Hemisphere by 3 to 5 degrees Celsius (37 to 41 degrees Fahrenheit). Although this is only about a third of the temperature decrease experienced during major ice ages, it is comparable to the climate change the occurred during the “Little Ice Age” in Europe from the 16th to 18th century, which significantly impacted the European economy.

Fortunately, abrupt climate changes that happen over the course of a few days — like the one in “The Day After Tomorrow” — are not likely to occur. According to the Woods Hole Oceanographic Institution, climate changes caused by a disruption in ocean circulation will probably happen over decades at the very fastest. Also, a shutdown of the Great Ocean Conveyor will not lead to a global “Ice Age” but rather regional cooling in areas of Eastern America, North Atlantic, and Western Europe.

Still, many scientists completely reject the theory that global warming will lead to cooling temperatures. Instead, they project that even if the Great Ocean Conveyor were to completely shut down, the temperatures of the affected regions would still increase, just at a slower rate than other areas.

Since the climate is dependent upon many factors, it is hard to predict what will be the exact effect of global warming. However, one thing that scientists do agree on is that global warming is definitely having an impact. So even though we might not all be completely buried under snow “the day after tomorrow,” we should still recognize that global warming is changing the Earth’s natural environment, and it’s a change for the worse — whether it’s going to get hotter or colder.

— Elaine Gu