Atmosphere
and Planets
What would it be like if IPCC is right and I believe they are and the temperature here on Earth rises from 3 to 6 degrees before the end of the century? That, by the way, is a conservative estimate. The IPCC always projects on the conservative side and with the additional rise due to feedback and other conditions which are as yet unknown actually means faster temperature rises and more intensive and qualitatively worse climate.
Professor James Lovelock, well-known for his Gaia hypothesis (collaborated with Lynn Margullis, who was the wife of Carl Sagan) - (Lovelock is also the inventor of the electron capture detector, a palm-size chamber that detects man-made chemicals in minute concentrations.) wrote:
"Three degrees does not sound like much but it represents a rise in temperature comparable with the global heating that occurred between the last ice age, some 15,000 years ago, and the warmth of the eighteenth century. When Earth was cold, giant glaciers sometimes extended from the polar regions as far south as St Louis in the US and the Alps in Europe. Later this century when it is three detrees hotter glaciers everywhere will be melting in a climate of often unbearable heat and drought, punchtuated with storms and floods. The consequences for humanity could be truly horrific; if we fail to act swiftly, the full impact of global heating could cull us along with the vast populations of the plants and animals with whom we share Earth. In a worst case scenario, there might -- in the 22nd century - be only a remnant of humanity eking out a diminished existence in the polar regions and the few remaining oases left on a hot and arid Earth." (from the Forward to Climate Change, Robert Henson) He goes on to write: "Earth is not the Goldilocks planet of the solar system sitting at the right place for life. It was in this favourable state some two billion years ago but now our planet has to work hard, against ever increasing heat from the Sun, to keep itself habitable." He suggest these are now the "worst of times".On Earth the atmosphere begins where the gases begin and the rocks end, but there are also gaseous planets where there are no rocks in which case there is some phase or density change which form the separation between the planet and the atmospheres.
On a planet like earth we have the core we believe is a solid and then it is molten and swiring around the core maintaining the electromagnetic shield which blocks radiation from solar flares. The atmosphere is a thin shell around rock or liquid water.
Is the Planet Really Warming Up?
"In a word, yes...In recent years global temperatures have spiked dramatically..." (Robert Henson, The Rough Guide to Climate Change - Royal Society Prize for Science Books in 2007
The gases we're breathing is oxygen and nitrogen and some argon. These various levels are the atmosphere. We live at the bottom of this gaseous ocean which is our multi-layered atmosphere.
"The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night (the diurnal temperature variation). Whatever the outer layer(s), it forms the atmosphere..." (Wikipedia)
Greenhouse Earth
Greenhouse gases in the Earth's atmosphere act as a partial blanket for the thermal radiation from the surface and thus enable the Earth to be substantially warmer than it would otherwise be, analogous to the effect of a glass greenhouse. This blanketing is known as the natural greenhouse effect.
"The atmosphere has a natural supply of "greenhouse gases." They capture heat and keep the surface of the Earth warm enough for us to live on. Without the greenhouse effect, the planet would be an uninhabitable, frozen wasteland." - Environmental Defense Fund
"Before the Industrial Revolution, the amount of carbon dioxide (CO2) and other greenhouse gases released into the atmosphere was in a rough balance with what was absorbed in natural sinks. For example, plants take in CO2 when they grow in spring and summer, and release it back to the atmosphere when they decay and die in fall and winter." (ibid)
Industrial Age Increases Greenhouse Effect
" Industry took off in the mid-1700s, and people started emitting large amounts of greenhouse gases. Fossil fuels were burned more and more to run our cars, trucks, factories, planes and power plants, adding to the natural supply of greenhouse gases. The gases which can stay in the atmosphere for centuries are building up in the Earth’s atmosphere and, in effect, creating an extra-thick heat blanket around the Earth."
The Early Ultraviolet Problem
"The genetic materials of cells (DNA) is highly susceptible to damage by ultraviolet light at wavelengths near 0.25 µm. It is estimated that typical contemporary microorganisms would be killed in a matter of seconds if exposed to the full intensity of solar radiation at these wavelength. Today, of course, such organisms are protected by the atmospheric ozone layer that effectively absorbs light at these short wavelengths, but what happened in the early Earth prior to the significant production of atmospheric oxygen? There is no problem for the original non-photosynthetic microorganisms that could quite happily have lived in the deep ocean and in muds, well hidden from sunlight. But for the early photosynthetic prokaryotes, it must have been a matter of life and death." - Global Change - U of Michigan"It is a classical "chicken and egg" problem. In order to become photosynthetic, early microorganisms must have had access to sunlight, yet they must have also had protection against the UV radiation. The oceans only provide limited protection. Since water does not absorb very strongly in the ultraviolet a depth of several tens of meters is needed for full UV protection. Perhaps the organisms used a protective layer of the dead bodies of their brethren. Perhaps this is the origin of the stromatolites - algal mats that would have provided adequate protection for those organisms buried a few millimeters in. Perhaps the early organisms had a protective UV-absorbing case made up of disposable DNA - there is some intriguing evidence of unused modern elaborate repair mechanisms that allow certain cells to repair moderate UV damage to their DNA. However it was accomplished, we know that natural selection worked in favor of the photosynthetic microorganisms, leading to further diversification." (ibid)
We have had other atmospheres. In the beginning there was gas from chemical reactions as planet Earth cooled. There was sulfide gases from vulcanos and water vapor and bursts of radiation blasting away the early atmosphere by the solar wind. Oxygen came later; it evolved to where it is now, about 21% with most of the rest nitrogen (78%) and the rest at about 1% - some argon and some other chemicals. Bacteria is responsible for much of the gas. The atmosphere was methane rich and now it has evolved into an oxygen breathing life on this planet. We have our atmosphere the way it is now because of life; because we have life.
"Other planets and moons in our solar system have atmospheres, but none of them could support life as we know it. They are either too dense (as on Venus) or not dense enough (as on Mars), and none of them have much oxygen, the precious gas that we Earth animals need every minute." - SciJinks
We are actually into Earth's third atmosphere (or more, if there was a before we know nothing about). This atmosphere makes it possible to have life here.
"So plants and some bacteria use carbon dioxide and give off oxygen, and animals use oxygen and give off carbon-dioxide - how convenient! The atmosphere upon which life depends was created by life itself." (ibid)
Some Molecules Do a Better Job
Some molecules do a better job of reflecting certain colors of light and some molecules do a better job of absorbing some colors of light so it seems that many of the small amounts have more control over what is bounced back into space and what radiation is not reflected away. We like ozone which is not a huge amount compared to other elements but it does not like to let ultraviolet light through the atmosphere. It acts as a sun screen, without which there would be more cancer - more radiation causing an increase in mutations which would have an increased harmful affect on our human biomass. If you recall a few years ago this was a huge problem when we used Freon in our air conditioners and these CFCs.
"Ozone can be found throughout the earth's atmosphere. In the lower atmosphere (the troposphere), ozone contributes to smog formation and is considered an air pollutant. However, in a higher region of the atmosphere (the stratosphere), the ozone layer absorbs ultraviolet radiation, which is harmful to humans, animals, and plants. In humans, the effects of chronic exposure to excessive ultraviolet radiation include skin cancer and cataracts. Moreover, excessive ultraviolet radiation impairs photosynthesis and disrupts plant metabolism, inhibiting worldwide food production. Scientists have discovered thinning of the protective stratospheric ozone layer at many latitudes and a seasonal ozone "hole" over the Antarctic in spring. They have linked this ozone depletion with increased emissions of a group of chemicals called ODSs. This group contains compounds such as chlorofluorocarbons (CFCs); hydrochlorofluorocarbons (HCFCs); halons; methyl bromide; 1,1,1-trichloroethane (TCA) (also referred to as methyl chloroform); and carbon tetrachloride. In the troposphere, these compounds are stable and inert. In the stratosphere, however, ODSs catalyze ozone-degrading reactions in the presence of ultraviolet radiation, thus reducing the concentration of beneficial ozone." NOAA
"In response to the scientific evidence demonstrating "holes" in the stratospheric ozone layer and the link between ozone depletion and ODSs, 23 nations signed an agreement in 1987 to control the production and use of ODSs. The agreement, called the Montreal Protocol, included provisions for regular reviews of the adequacy of ODS control measures. The adequacy of control measures was to be based on assessments of the ozone layer and other scientific, environmental, and economic information. There have been 10 annual follow-up meetings to the Montreal Protocol, where numerous additional agreements addressing the production and use of ODSs have been reached. To date, more than 160 countries including the United States, have signed the Montreal Protocol." (ibid)
"The National Oceanic and Atmospheric Administration (NOAA) is committed to phasing out the use of ozone-depleting substances (ODSs) throughout its operations. As one of the world's leading research agencies regarding the ozone layer, NOAA has made significant contributions towards advancing the scientific understanding of ODSs and their effects on the atmosphere."
Dr.Steven Hawking asks: "How can the human race survive the next 100 years?"
He answers, he does not know. He says it is important to ask the question in order to get people to think about it and beware of the dangers we now face. He says, and I will cite some of his remarks as follows. (and as usual, include some of my own comments)
"Before the 1940 the main threat to our survival came from collisions with asteroids." Such collisions with asteroids caused mass extinctions in the past but the last one was 70 million years ago. So the likelihood that we will need the services of Bruce Willis in the next 100 years is very small. The much more immediate danger is nuclear war (That threat is everywhere, i.e. North Korea, India versus Pakistan, Iran and the rest of the world, etc, or even Russia and the U.S.) The U.S. and Russia have more than enough war heads to kill everyone on earth."
Some of us have been saying this since the 50s. We had 30,000 aimed at Russian cities and while that figure is down to about 20,000 now the Russians are still armed to the teeth with worn out, obsolete nukes where only 10 would do and in fact we don't need them at all,but everyone wants their nuclear bombs and it is unlikely they will disappear. If some rogue terrorist organization gets their hands on one, that fear which has lingered and now rarely thought about becomes too real to ignore. Of course we can always "duck and cover".
I remember when I and my wife and kids had our own fall out shelter. That seemed like a good idea at the time. And our home was 2/3rds underground. It was very secure, if not also a bit paranoid (grin). It served more as a root cellar than a bomb shelter, but the reason we built it was for protection from a nuclear attack. And, now China sits on the same stage with Russia and the U.S., not to mention the the terribly dangerous events in Syria, North Korea and Iran - and once again the world is perilously close to having very troubling conditions for a potential extinction level event (ELE).
We have been close before to nuclear annihilation in the last 50-60 years. Because we are here at all is just plain dumb luck. Some would say, as Dr. Hawking has said,
"with the ending of the Cold War the threat has become less acute but it has not gone away."
There are easily enough nuclear weapons prepped and ready to use to ignite a conflagration. There is a huge new and growing danger from small unstable countries to acquire nuclear weapons which could cause millions of deaths and unimaginable carnage. Nuclear war is not the only danger. Climate change is happening at an ever increasing rate says Dr.Hawking and tens of thousands of scientists, including practically all of the climate scientists doing research in this area. Just the other day we also heard of new bio-weapons which have been developed so we know how to deal with them. These are very controversial experiments.. If bio-weapons are lost or stolen the consequences would be devastating.
Global Warming is Also a Game Changer
The IPCC has warned us, the science is very convincing and the concensus supports the facts that human activity is causing Global Warming and positive feedback is making it worse and the results will occur sooner. Credible climate Scientists are no longer debating the basic facts of climate change. The denialists who say otherwise are ignorant of the facts and perveyors of lies which will push us over the tipping point. Many believe it is possible that has already happened.
Our awareness of these potential dangers may give us a very small opportunity to do something about it. Some things can be fixed if we start now - but without the will to do all it takes the game is over and if we have already reached the tipping points and it is too late.
The loss of Arctic and Antarctic ice reduces the amount of radiation reflected back into space and increases the risks even further. The rising temperatures may release even more greenhouse gases from the ice and further increase the greenhouse effect.
Let's hope we don't end up like our sister planet, Venus with a surface temperature of about 250 degrees centigrade and raining sulfuric acid. Or, the release, accidentally of course, of a virus (we have the technology and government laboratories are constructing dangerous viruses) which will wipe out the entire human species and most of the other prokaryotes which are like us, carbon based organisms, which can't adapt to these extreme conditions. Dr. Hawking says each time we had more technological power we add more ways things could go vastly and uncontrollably wrong and trigger an ELE. As he rightly warns, species face more ways things could go disastrously wrong. He says it is not unimaginable even if it was possible for an alien civilization not to want to reach us because we are not willing to deal with these problems enough to make cooperation with other life worth while for them. If we care that little of ourselves why would any alien culture want to meet and cooperate with us?
He says we humans would be safe only if we spread out among the stars and try to make living together an advantage, not a threat to us, to other animals, and to any aliens who might be watching us evolve. Who knows? In thousands of years it might be different. I personally do not believe we can last that long. More likely our extinction will occur within centuries not millennia. .
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Today is Friday May 18, 2012
Hank Roth (on the Internet since 1982)