Evidence of the melting of the Greenland ice sheet is not proof that man-made greenhouse gases are responsible. The Greenland ice sheet went through a melting stage 1000 years ago – followed by a Little Ice Age.
Humans now control Earth’s climate, James Hansen of NASA told CBS’ “60 Minutes” last week. His evidence: the edges of the Greenland ice sheet are melting rapidly. Hansen says the speed of this melting proves that man-made greenhouse gases are responsible.
Sorry, Dr. Hansen, but the melting edges of the Greenland ice sheet don’t prove your point. Melting around the edges is exactly what the Vikings saw on Greenland 1000 years ago when they named the island—for its green coastal meadows. They moved in with their cattle, and thrived for 300 years, during what we now call the Medieval Warming.
The Vikings’ mistake was thinking that Greenland would stay warm, that the Earth’s climate was stable. Greenland was then warmer than today, and the summers were longer. There was ample grass and hay for the Vikings’ dairy cows. The Norse settlement grew to 3000 people.
Then Greenland’s climate suddenly got colder. The Little Ice Age had begun. Sea ice moved south, and the Vikings’ sailing ships could no longer get through to trade wood for seal furs. Shorter summers produced less hay to feed the Viking cows through longer, colder winters. The last written record found in the abandoned Viking colonies was dated 1408.
Our panic-prone scientists seem to have forgotten their own ice cores, drilled deep into the Greenland ice sheet in the 1980s. These ice cores document a natural, sudden-but-moderate 1500-year global warming cycle. Oxygen isotopes in the ice layers show 300 worldwide warmings over the past 500,000 years.
The ice cores tell us that variations in the sun are constantly warming and cooling our planet. The big Ice Ages come about every 100,000 years. The warm interglacial periods like our own last about 10,000 to12,000 years.
Through it all, however, runs the moderate, natural 1500-year climate cycle that raises temperatures about 2 degrees C above the mean for 750 years or so—and then abruptly drops the temperatures 2 degrees C below the mean (at the latitude of northern Europe).
Man’s climate impacts are puny compared to the million-degree heat of the sun. There’s no evidence that human-emitted CO2 has added much to the current temperatures. Our moderate warming to date—0.8 degree C—virtually all occurred before 1940, and thus before much industrial development.
If you want to talk about sudden, ice cores from the Freemont Glacier in Wyoming show it went from Little Ice Age cold to Modern Warming warm in the ten years between 1845 and 1855. Naturally.
Greenland today has 20,000 people, 50,000 sheep and a sizeable fishing industry. But the climate cycle will turn in a few more centuries. Then Greenland’s sheep will be in serious trouble and its fishermen will need icebreakers to reach the fishing grounds. (There were no fish bones in the Norse colonies’ trash heaps).
As for melting ice from Greenland flooding London, remember that it didn’t happen during the Medieval Warming, so it’s unlikely to happen in the Modern Warming. The melting of 100 cubic kilometers of Greenland ice would raise sea levels by only 0.01 inch. Dr. Hansen should know that recent satellite research shows Greenland’s interior ice sheet has thickened 2 inches in the past 11 years, because warmer temperatures are evaporating more seawater to make more snow.
The Vikings can be forgiven for missing the 1500-year climate cycle. They didn’t have thermometers, written records or the ice core histories. NASA’s Dr. Hansen cannot be let off the hook so easily.
Do you believe in evolution? Perhaps conservatives like you are evolving right now into ostriches, since your so good at burying your heads in the sand.
Excellent. In times when disinformation and bad science rule the perceptions of majority, it is important to not forget about the facts that have ruled our planet for millions upon millions of years.
Mr. Avery,
Thank you for posting this article.
It is hard to reconcile the supposed human factors in global warming with the geologic evidence that our planet was some 7 degrees warmer (Celsius) in the Triassic and Jurassic periods.
Much before that, the planet was much hotter, as dusts become liquid, and gasses are gathered: silicon, iron, calcium, magnesium, oxygen, nitrogen, hydrogen, etc. under gravitational action, coalesce to form our planet.
Our planet is still in the act of cooling. Volcanic action is part of that. The fact that it has slowed in the last 5 billion years is that same fact that makes the place hospitable to us at all.
The atmosphere was once very different. The transformation of that atmosphere occurred in part, but not exclusively because of, the abiotic life present at the time. The layers of material in the Earth’s crust suggest it. Metal rich layers exist globally. Most are the result of natural geologic separation, but some are due to the precipitation of microbes sequestering various metals in their cell structure, dying, and collecting on the bottom of whatever sea existed. The examples I hold in evidence of this are the concentration of Uranium in Africa, which with ground water, self moderated a natural nuclear reactor for thousands of years before we came about, and the dolomite (Magnesium) and limestone (Calcium) layers we depend on for concrete and building supplies.
In relatively recent times, there have been many “Ice Ages”. I live in Ohio, and the geologic evidence abounds here. Ice has scoured the surface of almost half the state.
The evidence of large reptilian creatures in the West and South of our continent suggests that the warming of our planet is not a bad thing. In order to support such life, the vegetable material would have had to be more abundant than today. Sand cannot feed a Tyrannosaurus Rex.
Our planet is cooling, and there is nothing we can do about it. Any warming is a temporary gift. Our star, the Sun, has the greatest role to play in this aspect. Despite our planetary cooling, in about 5 billion years, it will run out of Hydrogen to fuse. As that happens the Sun will go through expanding and contracting cycles as gravity and atomic fusion combat. Any one of those cycles could cook the surface of the Earth. Certainly, as the transition approaches, the Earth will be dissolved in a small solar nova. If anything remains, it will resemble the planet Mercury.
I do believe that evolution occurs. In the long run we should evolve (technologically?) to get off this planet. It is dead meat. (But not in a tasty way.)
Earth is our crib, what lies beyond? So far we have only stuck our arms through the crib’s slats.
By abiotic, I meant anaerobic, sorry.
Duh, that was a pointless remark that totally fails in any way to refute the assertions of the article. The point is, if you so adamantly believe humans cause global warming, provide some sort of compelling evidence. As usual, the liberal have nothing substantial to say so they revert to their fall back mode of calling names, accusing people of ignorance, calling people bigots, accusing people of being in some hazy, poorly defined state of hypocrisy, etc. Calling people ostriches only re-enforces my beliefs.
Those who argue that climate change is an impending disaster (and they are on BOTH sides of the political spectrum) must answer three questions -
Firstly, is the planet really getting warmer? Many now claim that the planet is getting cooler.
Second, if the planet is warming (or cooling), is such a process being caused by mankind? We have abundant evidence to prove it happens quite regularly, irrespective of Earth’s living creatures. You’ll need a lot of science to back up a claim of human interference.
Third, if, after all this, humans ARE causing a change in the planet’s climate, will the damage be extensive, irreparable, or even harmful at all?
If, using verifibale science you can answer all these questions, THEN I’ll start subscribing to your ‘close the factories and unemploy millions of people’ newsletter. Until then…
The story of the Vikings in Greenland is very interesting. One point you missed is what happened about 1454 after the very large volcanic eruption in 1452-53, the largest seen in Antarctic ice cores for 3000 years. I doubt the Vikings would have survived the summer of 1816, either. and, please note that the 1500 year cycle you mention is still a hypothesis, not a scientific theory. I do hope you will learn a bit more about climate history in future.
Ah, I remember those days of yore! Life was slower then and we Vikings enjoyed our lives. Now there is a scouge of Crackberry addiction. We should all release ourselves from high tech and return to the simple ways of our people.