How the climate has changed over time

AccuWeather

AccuWeather Founder and Executive Chairman Dr. Joel N. Myers discusses how the Earth's climate has changed over time and how that has affected the weather.

Transcript

00:00Well it's always good to be with Dr. Joel Myers, AccuWeather's founder and

00:04executive chairman, today to talk about climate change. Dr. Myers, how has the

00:09climate changed over time? It's changed dramatically, obviously over most of the

00:15history of the world there's been little or no ice. It's been warmer than it's

00:19been and more recently, but over the last two million years there's been two great

00:25advances and retreats of the ice and it's hard to believe but just 12,000

00:31years ago we were in the heart of an ice age, 12,000 years ago, and at that time

00:37the ice was more than two miles thick over Montreal, Canada. So the northern

00:43continents, the northern hemisphere, covered by ice down to New York City.

00:48There was a southern boundary that's across the United States, Canada all under ice for

00:52the most part, so much of the United States was unlivable. It was just so

00:57cold and then the ice started melting and at that time the water levels in the

01:03ocean, because there was so much ice on the continents, was 450 feet lower than

01:08it is today. So there was much more land accessible. That was just 12,000 years

01:16ago and at that time there was between 1 and 10 million humans on the entire

01:22planet. So it was a whole different world and so then gradually was warmed

01:29as the ice melted and but when we fell into the Little Ice Age from 1300 to

01:351850, which was quite cold, a lot of crop failures and so on, and then we started

01:41coming out of it and warming naturally and then of course over the last 70

01:47years humans have contributed significantly to further warming and

01:51we've seen the effect of that particularly over the last couple of

01:54decades. And in what ways has the warming atmosphere affected extreme and

02:00severe weather in terms of impact and frequency? Greater water vapor in the air

02:04as the temperature warms, so you have more fuel for heavier rains. Hotter

02:10temperatures mean stronger updrafts which condense more water vapor out of

02:15the atmosphere, leads to bigger hailstorms, can lead to more violent

02:20tornadoes, and of course hurricanes. If everything is right, a hurricane can be

02:28more intense than it might have been with cooler ocean temperatures and so

02:35more rain, even more wind potentially, some more category 4 and 5 storms in

02:40certain situations. Well Dr. Joel Myers, great to be with you to talk about

02:44climate change. My pleasure as always.

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