Gee could the absence of observable global warming simply mean there never was any global warming?
“Gee could the absence of observable global warming simply mean there never was any global warming?”
No. There has been an overall long trend of global warming since the beginning of the current inter-glacial with shorter episodes of global cooling along the larger uptrend in global warming. Such a global warming has been a natural occurence beyond question in the absence of a human industrial age, and in those time periods in which there have been no humans in existence.
Although there has been a general trend of natural global warming during the current inter-glacial sincee about 10,000 to 12,000 years ago, this warming inter-glacial is occuring during a much longer ice age featuring some of the most dramatic global cooling the Earth has experienced in the last 2.2 billion years, when most of the Earth was covered by an ice sheet on land and sea. The current and ongoing ice age has been going on for about some 20 million years, and the Arctic ice cap has been in existence off and on again over a period of 6 million years or less. The presence of an ice cap in the Arctic is extremely unusual, even during the ice ages of Earth’s past. The current ice age and the Arctic ice cap are apparently due to the gradual thinning of the Earth’s atmosphere.
The Earth’s atmosphere has been underggoing radical changes in mass and composition for the past 4.6 billion years. The Earth’s first atmosphere some 4.6 billion years ago was far far more massive than now, and its was heavily dominated by hydrogen and helium and much lesser amounts of ammonia and meethane. The Earth’s gravity was insufficiently strong to prevent the hydrogen andd helium gases from reaching escape velocity and esacaping the Earth’s gravity into the inter-planeetary space when stripped by the Solar winds. This left behind the Earth’s second atmosphere, which was upwards of 100 times the current mass and atmospheric pressure and composed of nearly all carbon dioxide.
When aerobic lifforms developed about 2.2 billion years ago, the microscopic marine lifeforms began consuming the carbon dioxide out of the atmosphere and depositing it into the lithosphere as carbonate compounds and oxygented compounds such as rust or iron oxide. This process continued until the atmospheric mass and pressure was reduced from ~100 atmospheres to the current 1 atmosphere, and the dissociated oxygen built up in conceentration with the other formerly trace concentrations of gas like nitrogen to become the principal components of our present atmosphere.
When aerobic life changed the Earth’s atmosphere from being composed of nearly all carbon dioxidee to small fractions of dioxide and noow miniscule trace amounts of carbon dioxide, a catastrophic global cooling occurred which nearly turned the Earth into an iceball from polee to pole. Eventually, the Sun increased its luminosity, geological weathering changed the environment, and a variety of factors finally brought about a global warming that left the Earth far warmer than at present for thousands of millions of years. The very few ice ages never reached the intensity of the Cryogenian ice age/s, until the current ice age began to rival all but those most ancient ice ages. fr the first time since the Cryogenian, the ice sheets reacched out farther than the other ice ages since the great Cryogenian catastrophe. Why?
The answer to why the current ice age has been so severe is at best arguable, but it hs to be noticed that the Earth is continuing to see a thinning of its atmosphere. This thinning of the atmosphere inevitably results in a loss of heat over time. It remains to be seen how such very long term events as atmospheric loss versus Solar luminosity impacts global climates and variability in the human time frames of 6 million years and less.
Ultimately, the Earth is destined to have no weather and no climate apart from that of inter-planetary space. The Sun will increase its luminosity and size until the Earth’s atmosphere and hydrosphere are vaporized and stripped by Solar winds to be pushed into the outer Solar system and the gravitational attraction of the Jovian planets. Unless the decreasing mass of the Sun changes the orbit of the Earth enough to move outwards towards mars current orbit, the Earth will suffer the same fate as Mercury and Venus, which is their complete vaporization as the Sun grows in size to engulf them.
Now that is GLOBAL WARMING!!!