Historical Ice Ages Address 'Natural' Climate Change

Ice ages have come and gone many times in Earth's history. But do these natural occurrences hint any of the things that are devastating the situation of our environment?

By the initiative of CNN's John D. Sutter, "Two Degrees" encourages people to ask questions on climate issues that could shape the network's coverage on tackling global warming and large-scale climate shifts. Recently, the initiative focused on a not-so-unfamiliar question which "travels a long way back in time."

Jonas Martin of Seattle asked via CNN: "There have been hundreds, if not thousands of ice ages in the past, before humans walked the Earth. How was this extreme climate change possible without humans, and isn't climate change natural?"

"The quick answer to the first part of the question, which is likely already known by most who pose the question in the first place, is yes. The Earth's climate has changed, many times, going back millions of years." CNN meteorologist Brandon Miller wrote in the article.

But how did these climate changes happen sans human intervention?

According to Miller, there are natural processes that lead to ice ages. These warm and cold periods, occuring in regular patterns, are called Milankovitch cycles. Such take place due to the earth's changing orbit around the sun.

The planet experienced these repeated cycles of glacial (cold) and interglacial (warm) periods for about 80,000 years on average, Woods Hole Oceanographic Institution (WHOI) noted. WHOI is the world's largest private, non-profit oceanographic research institution, a global leader in the study and exploration of the ocean.

But Miller points in a perspective that is not commonly addressed regarding the issue of global warming. He stated that these cycles happen very, very slowly nowadays, that they "take place on 100,000 year time frames, and the amount of warming we have seen, even though it is 'only' about 1.5°F (0.85° C) since 1880, would take many thousands of years to occur if the process were occurring purely naturally."

As much as people could not be blamed solely for melting ice sheets and higher sea levels, Miller suggested that what gradually increases the primary concern towards the Earth's atmosphere is the continuing rise of greenhouse gases, a side effect of human activity geared to improving infrastracture and economy.

On the conclusion of Miller's discussion with the question earlier, he placed us on the edge of choosing between the Earth's sudden shift of climate and our ways of bringing back the natural order. For when these rapid changes continue to affect the Earth's atmosphere, the world might face mass extinctions in the future.