Interesting find Chaos. Yes, a potential significant reduction in energy output from the sun, which is my understanding of what that article is about, definitely would trigger global cooling if it does happen over an extended period. Regardless of greenhouse gasses or not, that would at least slow any GW trend if not reverse it if it's as bad as some such solar cycles have been in the past.
There are also 2 out of 3 Earth-based cycles that also favor a global cooldown, Earth's orbit, which is not a constant distance from the Sun year round, or a perfect circle but rather is somewhat elliptical, and right now we're in a stage where the north is further from the sun in the summer, which gives more distance for the sun's energy to diffuse as it travels here (less energy overall reaches Earth as a result) and the cycle of progression, which is the orientation of Earth's axis, which also causes the northern hemisphere to get less energy from the sun in its current stage in the cycle. The 3rd Earth based cycle, in the one that actually favors a natural global warming, and is the one that usually has the most effect too, that's the angle of Earth's axis, which cyclically varies from about 21 degrees to about 24 degrees, and it currently at about 23.5 degrees. This effects how hot the summers are, and the biggest contributor to global icing is cool summers, and not so much bitterly cold winters as most might expect. So the cycle of Earth's tilt that most favors ice build-up and thus global cooling as the ice makes Earth more reflective* is when it's at the 21 degree tilt.
The main idea behind GW is that certain substances, when suspended in the atmosphere act as a layer of insulation, trapping energy within Earth's atmosphere that would otherwise escape. Too little greenhouse gasses and Earth would become much like a cooler version of Mercury, Deadly hot in the day, deadly cold at night as the sun's energy would have few barriers to entering the Earth, and the Earth's energy would have few barriers to leaving. Too much greenhouse gasses and the Earth becomes like a slightly cooler version of Venus, energy can't easily enter the Earth, true, but it also can't easily escape, and since the sun outputs far more energy at the Earth's distance, that the Earth does, more energy will enter then leave, causing temperatures to nearly continuously trend upwards, until they approach the amount of energy that's being received from the sun. Of course these are the ultimate extremes, as Mercury has virtually no atmosphere and Venus has a thick atmosphere that's about 98% CO2, whereas Earth has the right atmospheric thickness for life and the CO2 levels are currently at 0.0360% or 394.45 ppm (Sources:
The Encyclopedia of Earth Scientific Psychic)About 500 million years ago CO2 levels were about 20 times today's levels, and I do remember from my Geology class last summer that global sea levels were far higher then they are today, in fact about 50% of North America's present day landmass was underwater. Then CO2 levels dropped off and sea levels also dropped off exposing the previously underwater parts of North America's land. Then CO2 levels rose again to about 4-5 times current levels about 200 million years ago, right in the middle of the age of dinosaurs, and again more then half of the present day North American landmass was underwater. Since then CO2 levels have been steadily falling off to around their present day levels, at least until the rise of the industrial age when they have begun to rise again. (Source:
Climate Change Past and Future)
During the periods of high CO2 levels, Earth's temperatures rose dramatically and the planet became largely tropical, with massive plant tropical style plant growth accompanying each such event from about 420 million years ago onwards. Before 420 million years ago there were no land plants yet.
The other thing to keep in mind, is that naturally occurring cyclic changes, barring a sudden catastrophic event, which is easily detectable, take place over a period of 1000s or more years, very slow by our standards. The currently observed changes in temperatures and CO2 levels are taking place over a period of decades or centuries, not millennia or aeons. Decades! That's shorter then a geological eyeblink!
Now, we are still far from CO2 levels being enough to do anything like those dramatic events of the past, but if we continue to do what we are doing, and not find better ways of doing things, we will reach critical levels quickly. With places like China, India and Africa modernizing at a phenomenal rate, the increase in pollutants and climate altering substances in the environment will increase exponentially. The time to change our ways to clean energy sources and clean building practices is now, not when we're in the middle of a major global crisis of climate change, sea level raise and massive storms that would make those typhoons that devastated the Philippines look like a light shower! To deny that we're having an effect on our environment when the evidence is all around us, and the start of unnaturally rapid trends like the CO2 raise, temperature changes and such, to me seems ridiculous. All it takes is looking. By looking you will see those factories pumping poisons into our breathing air, drinking water, and farmlands. you will see the car exhaust poisoning our air, don't believe me, just try locking yourself in your garage and running your car, I doubt you'd survive the experience for long.
The thing of it is, we have good, clean energies now, we just aren't using them, we're too busy ridiculing the developers because we just can't believe it's possible to make our energy without poisoning ourselves, or to manufacture products without poisoning ourselves. What we don't know how to do clean now, we
can learn how to do clean if we're willing to put in the effort needed to develop ways to do things clean. Poisoning ourselves is NOT an unavoidable part of progress, it's just that, poisoning ourselves. We are perfectly capable of clean progress if we want it and are willing to work for it, and support it.
I am not an engineer, chemist or physicist to do the research myself, and I wouldn't want to be one of those professions, they just aren't within my area of personal interest, aside from knowing generally how they affect me. That does not mean I can not and am not supporting clean energies by encouraging those who are interested in and good at the sciences needed to develop clean technologies. That does not mean I can't support those who are needed to do the direct research in other ways, by providing the services these people desperately need in areas they are not good at or interested in, but that I am.
I don't know who originally said this but
it takes a village to raise a child
and likewise, it takes a community to solve problems and survive.
Additional source: Levin, Harold.
The Earth Through Time. 9th Edition. Publisher: John Wiley & Sons.
* Note: ice and snow send about 90% of the energy that hits it back, so most of the sun's energy goes right back out into space when the Earth is heavily iced over as in an Ice Age, whereas rock and liquid water both absorb more of the sun's energy then reflect it, meaning more energy that reaches Earth's surface stays at Earth's surface, causing warmer temperatures.