This is a contentious topic. No doubt. Here’s the truth all scientists agree on: Earth gets warmer and colder, goes in and out of Ice Ages. Even Ice Ages have warming trends. We are in a warming trend in the most recent Ice Age. Eventually (not in our life time), Earth will pass out of the warming trend, back to the coolness of a frigid Ice Age.
Posts Tagged ‘ice age
In the late 1800′s, scientists were convinced we were in global cooling. The Times reported on Feb. 24, 1895, that geologists predicted the world would soon be frozen again.
Then they switched to global warming…
Remember the 1970′s (if you’re in your fifties, you do) when scientists believed we’d returned to Global Cooling. Here’s a poem descrying the impending ice age: The ice age is coming, the sun’s zooming in. Engines stop running, the wheat is growing thin. A nuclear era, but I have no fear ’cause London is drowning and I live by the river. –London Calling, released 1979
Then, thirty years later, they declared global warming–that Arctic ice was melting at record levels (according to scientists–some scientists). This could increase the rise of the sea level and block the Gulf Stream, and trigger a new ice age.
In all, the print news media have warned of four separate climate changes in the past 100 years. If you’re like me, you’re sick of the hype and looking for facts. Here are a few:
it’s been getting colder for 10 years
accuweather
Don’t believe me? And you no longer believe the major news outlets (I hope). Try the primary source:
Data from UAlabama and NOAA
There are reasons for global cooling, the biggest being that Earth has been in an Ice Age for the past 18,000 years. This is a slight break in the cold before our planet returns to its normal cold state which will last until the end of this current Ice Age.
What can we conclude from 100 years of conflicting media coverage?
- Their record speaks for itself. Four separate and distinct climate theories targeted at a public taught to believe the news. Only all four versions of the truth can’t possibly by accurate.
- For ordinary Americans to judge the media’s version of current events about global warming, it is necessary to admit that journalists have misrepresented the story three other times.
- Yet no one in the media is owning up to that fact. Newspapers that pride themselves on correction policies for the smallest errors now find themselves facing a historical record that is enormous and unforgiving.
- It is time for the news media to admit a consistent failure to report this issue fairly or accurately, with due skepticism of scientific claims
Is global warming the result of man’s activities, or natural occurrences? It’s possible, that powerful force that’s melting the glaciers and driving polar bears to extinction is simply an example of ‘what goes around, comes around’. The average life span of a mammalian species is two million years. Maybe, like the dinosaur (who lasted longer than 150 million years), polar bears are just running out of time.
Scientists have hypothesized since the early 1900′s that one of the causes of the ice ages is the changing tilt of the Earth and its elliptical path around the Sun. This was originally called Croll’s theory, fine-tuned by Milankovich, and can be summarized as:
Disturbances of the Earth as a planet by the Moon and the Sun cause a periodic shift in the position of perihelion. The shift has a precessional period of about 21,000 years. The shift affects the distribution of solar heat received by the Earth. The result will be that any given point at a high latitude in the northern hemisphere will be affected accordingly.
When the Earth’s orbit and tilt change, Ice Ages happen. Milankovich drew an involved relationship that is accepted (with some discussion) even today:
The following article suggests it might be a chicken-or-egg problem: Are the Ice Ages caused by changes in the elliptical orbit, or does the orbit change because the Earth is cooling? Ice melts, fills the oceans (the article suggests that Earth’s increasing temperature results in warmer oceans, despite the cooling effect of ice cubes in the ocean… A discussion for another day), earth tilts.
See what you think.
Warming Oceans May Cause the Earth to Tilt
Global warming and expanding oceans may even cause the earth’s axis to shift
Human activity has widely affected our planet, reshaping surfaces, moving or extinguishing species, and warming the air and water. Now scientists say our reach has been extended even further — warming oceans may even start to shift the Earth’s axis of rotation.
Previously, the effect of warmer water temperatures was thought to be negligible and not strong enough to tilt the earth. But in a new study in Geophysical Research Letters, researchers have found that global warming and the resultant expansion of the oceans could actually shift our rotational axis significantly.
Warming causes our axis to shift because warmer water takes up more space than cooler water, and actually expanding upward and outward as it warms. Increased water volume pushes up onto shallow continental shelves, redistributing weight on the planet and causing the Earth to tilt. According to the report, the north pole of our rotational axis will travel around 1.5 centimeters a year in the direction of Alaska.
That’s not much, in the context of other forces and movement. (The earth wobbles around as much if not more under other influences, including seasonal changes, melting glaciers, and retreating ice sheets.) But it is significant enough that the effect of warming should be taken into account when monitoring the way our axis moves in the future, the researchers report. Moreover, it represents just how strong the effects of human caused global warming can be — even moving the planet itself.
[via New Scientist and Discovery News]
