Is the Earth Really Getting Warmer?

Curious whether the Earth is warming or cooling? Then study the planet’s history.

Since the birth of Earth as a planet and the emergence of life, the Earth’s temperature has repeatedly risen and fallen many times. There were extremely cold periods, such as the Ice Age when giant mammoths roamed, while there were also times when temperatures were much higher because the atmosphere contained more greenhouse gases.

The era when the dinosaurs we all know lived was the Mesozoic. At that time, there were more greenhouse gases in the atmosphere than today, and temperatures were also far higher than they are now. In fact, the dinosaurs’ enormous size was, in a sense, a product of that warm climate.

The Earth’s average temperature gradually rose from around the Archean, when life first appeared on the planet. Then, after repeatedly reaching peaks across the Paleozoic and Mesozoic, it entered the Cenozoic—the age we live in—and has shown a marked downward trend.

In other words, contrary to the common perception that worries about “global warming,” the Cenozoic era in which humanity lives is clearly colder than the earlier Paleozoic or Mesozoic eras.

Then why, exactly, did the Earth become especially cold during the Cenozoic? The answer is Antarctica. It was during the Cenozoic that the current distribution of the continents was established. A massive landmass happened to drift down into the frigid polar region, leading to the formation of a vast glacial continent on Earth.

A continental-scale ice sheet of that magnitude dragged down the Earth’s overall average temperature. That is why many climatologists refer to Antarctica as “Earth’s air conditioner.” In fact, 90 percent of the world’s ice is in Antarctica, so that description is hardly an exaggeration.

The Earth in the 21st century can be described as being in a period between ice ages. More specifically, it may be classified as the fourth interglacial following the fourth ice age. The three previous interglacial periods all had higher average global temperatures than today.

Although scholars differ somewhat in their views, some now argue that the fourth interglacial is gradually coming to an end and that the Earth is moving back into a fifth ice age. Looking at the temperature trend over the Cenozoic, they say that temperatures are more likely to fall in the future than to rise.

The core argument behind claims of global warming is this: so-called “greenhouse gases,” centered on carbon dioxide, continue to increase in the atmosphere. The amount of carbon dioxide in the atmosphere has steadily risen due to human industrial activity, and this, it is said, will alter the Earth’s environment in the future.

But much of the carbon dioxide humanity has emitted was originally already on Earth. The coal and oil that humans have burned and released into the atmosphere consist mainly of carbon that was once contained in the bodies of plants and animals that lived on Earth. And the carbon those plants and animals carried was matter that had already existed on Earth since ancient primordial times.

Human beings are often called “the lords of creation.” But the Earth is not so easily affected that human activity alone could shake the atmospheric environment to that extent. The claim that industrial development is heating the planet can only invite a wasteful debate that undermines the economy.

Sung-no Choi, President of the Center for Free Enterprise (CFE)

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Original title: 지구는 정말 따뜻해지고 있나

Author: Sung-no Choi

Date: 2017-06-14

Source: https://www.cfe.org/bbs/bbsDetail.php?cid=press&pn=27&idx=11091