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  • The only constant... is change.

  • That's true about life. And it's true about the climate. The climate has been constantly

  • changing since the earth was formed 4.6 billion years ago.

  • For example, in just the past 2000 years, we have seen the Roman Warm Period,

  • when it was warmer than today...Then came the cooler Dark Ages... Followed by the Medieval Warm period,

  • when it was at least as warm as today... Then we had the Little Ice Age -- that drove

  • the Vikings out of Greenland. And, most recently, a gradual 300-year warming to the present day.

  • That's a lot of changes. And, of course, not one of them was caused by humans.

  • During the past 400,000 years, there have been four major periods of glaciation

  • -- meaning that vast sheets of ice covered a good part of the globe -- interrupted by brief interglacial periods.

  • We are in one of those periods right now. This is all part of the Pleistocene Ice Age

  • which began in earnest two and a half million years ago. It's still going on,

  • which means that we are still living in an ice age. That's the reason there's so much ice at the poles.

  • Thirty million years ago the earth had no ice on it at all.

  • So, then, what about carbon dioxide, the great villain of the Global Warming alarmists?

  • Where does that fit in to this picture? Not as neatly as you might think.

  • Temperatures and carbon dioxide levels do not show a strong correlation. In fact,

  • over very long time spans -- periods of hundreds of millions of years --

  • they are often completely out of sync with each other.

  • Over and over again, within virtually any time frame, we find the climate changing

  • -- for reasons we do not fully understand. But we do know there are many more factors in play

  • than simply the concentration of CO2 in the atmosphere -- factors such as the shape and

  • size of the earth's elliptical orbit around the sun, activity from the sun, and the amount

  • of wobble or tilt in the earth's axis, among many others. Even the relatively short 300-year

  • period from the peak of the Little Ice Age to the present has not been steady.

  • The latest trend has been a warming one, but it began nearly a century before there were significant

  • carbon dioxide emissions from burning fossil fuels. And, there has been no significant

  • warming trend in the 21st century. Contrary to media headlines,

  • the trend over the past couple of decades has been essentially flat.

  • Meanwhile human-caused CO2 emissions are higher than ever. About 25 percent of all the CO2

  • emissions from human sources have occurred during this period of no net warming.

  • So, what are we in for next? Will the temperature resume an upward trend?

  • Will it remain flat for a lengthy period? Or, will it begin to drop? No one knows.

  • Not even the biggest, fastest computers.

  • All the information I've presented -- the increases, decreases and plateaus in temperature

  • over the ages and into the last centuries -- is available to anyone who wants to seek it out.

  • Yet to state these simple facts is to risk being called a "climate change denier."

  • Not only is that absurd, it's mean-spirited. It's absurd because no one, not even the most

  • fervent skeptic, denies that the climate is changing. And it's mean-spirited because to

  • call someone a climate change denier is to intentionally link them to people who deny the Holocaust.

  • So, maybe it's time to stop the name-calling.

  • Predicting the climate, one of the most complex systems on earth with thousands of inputs,

  • many of which we don't understand, isn't an exact science, or anything close to it.

  • Maybe it's just a tad arrogant to suggest that we can predict the weather or the climate

  • or just about anything 60 years from now.

  • The science is not "settled." The debate is not over. The climate is always changing.

  • It always has. And it always will.

  • I'm Patrick Moore, Co-Founder of Greenpeace, for Prager University.

The only constant... is change.

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關於氣候變化,他們沒有告訴你的是什麼? (What They Haven't Told You about Climate Change)

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    gotony5614.me97 發佈於 2021 年 01 月 14 日
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