Climate changes

A.Paulita Roa

FIRST, it was Typhoon Sendong, then Typhoon Pablo and the super typhoon Yolanda and other natural disasters that is happening one after another around the world. All these are attributed to climate changes. However, many are not aware of the fact that the earth underwent several climate changes and global warming millions of years ago so it is best that we have a basic knowledge about this for after all, this is the planet that we all belong.

Brian Fagan, an archaeologist and an authority on world prehistory wrote in his book titled, World Prehistory: A Brief Introduction (2002) that:

“The story of humanity begins deep in geological time during the later part of the Cenozoic Era, the age of mammals. For most of geological time, the world’s climate was warmer than it is today. During the Oligocene epoch, some 35,000,000 years ago, the first signs of glacial cooling appeared with the formation of a belt pack of ice around Antarctica. This development was followed by a major drop in world temperatures between 14 and 11 million years ago.

“As temperatures fell, large ice sheets formed on high ground in high latitudes. About 3.2 million years ago, large ice sheets formed on the northern continents. Then some 2.5 million years ago, just as humans first appeared in tropical Africa, glaciation intensified even more, and the earth entered its present period of constantly fluctuating climate.

“The words ‘Ice Age’ conjure up a vision of ice-bound landscapes and frigid sub-zero temperatures that gripped the earth in a prolonged deep freeze. However, in the Pleistocene epoch, the most recent interval in earth history which began at least 1.8 million years ago, there were constant fluctuations between warm and intensely cold global climates.”

It was observed that these climate changes occurred in a span of every million years and later, every thousands of years.

Also, the presence of land bridges such as those that linked Palawan with the much of Southeast Asia and the subsequent disappearance of the land bridges were the result of the rise and fall of sea levels around the world thousands of years ago. Now, we are told that the sea levels are rising again as parts of the polar region are melting. One might ask how is it possible for scientists to be able to know and date all these climate changes that happened millions of years ago? The answer is found under our seas.

I am quoting excerpts taken from the chapter on  Environmental Archaeology from the book of Colin Renfrew and Paul Bahn  titled, Archaeology: Theories, Methods and Practice  (2012):

“Because three quarters of the earth is covered with water, it is possible to extract data from the seabed and reconstruct past environments, particularly for earlier periods.

“There are ‘sea cores’ – microscopic fossils that are extracted on the ocean floors and analyzed in laboratories. As in an archaeological stratigraphy, one can trace changes in environmental conditions by studying these sea cores. There was one case where a deep sea core taken off the coast of West Africa that led to estimates of wind strength over the last 700,000 years ago.

“What the scientists found alarming is that the ice cores taken from Greenland and Antarctica suggest that the next ice age should be about 15,000 years in the future; however, the stability of our climate has been overturned by the effects of human activity, and the ice shows that today’s greenhouse gas concentrations in the atmosphere are the highest for at least 440,000 years.

“The current rate of increase of greenhouse gases (high carbon and methane levels that indicate periods of global warming) is over 100 times faster than anything so far detected in ice cores dating back half a million years ago.”

Sad to say that we are all guilty of not taking good care of the environment. We have exploited and abused our natural resources, polluting the waters and even the air. The result is rapid climate changes and the possibility of more harm done to the very planet that we live in.