Explain how rising atmospheric concentrations of oxygen affected life on Earth?
609697
Here's one theory:\n\nClimate Model Links Warm Temperatures to Greatest Extinction\nWork supports theory that rise in levels of carbon dioxide triggered die-off\n\n\n\nScientists at the National Center for Atmospheric Research in Colorado have created a computer simulation showing Earth's climate in unprecedented detail at the time of the greatest mass extinction in history.\n\nAccording to an August 24 press release from the U.S. National Science Foundation (NSF), the work supports a theory that an abrupt and dramatic rise in atmospheric levels of carbon dioxide triggered the massive die-off at the end of the Permian Era, 251 million years ago.\n\nDuring that time, an estimated 90 percent to 95 percent of marine species and 70 percent of land species became extinct -- an extinction even greater than that of the dinosaurs, 65 million years ago.\n\nMany scientists equate high concentrations of carbon dioxide with warmer temperatures, and a close correspondence has been found between carbon dioxide and temperature for the past 570 million years.\n\nAt the end of the Permian, Earth had a single landmass (a supercontinent) called Pangea. Higher-latitude temperatures were 10-30 degrees Celsius warmer than today, and volcanic activity had released large amounts of carbon dioxide and sulfur dioxide into the atmosphere over a period of 700,000 years.\n\n"The implication of our study is that elevated [carbon dioxide] is sufficient to lead to inhospitable conditions for marine life and excessively high temperatures over land would contribute to the demise of terrestrial life," the authors concluded.\n\nTo understand how such conditions might have affected climate and life around the globe, the researchers used the Community Climate System Model (CCSM), which can integrate changes in atmospheric temperatures with ocean temperatures and currents.\n\nThe CCSM indicated that ocean temperatures warmed significantly at higher latitudes because of rising atmospheric levels of carbon dioxide, a greenhouse gas.\n\nIn the ocean, warmer temperatures reached a depth of about 4,000 meters, interfering with the normal circulation process in which colder surface water descends, taking oxygen and nutrients deep into the ocean.\n\nAs a result, ocean waters had little oxygen, proving deadly to marine life. Because marine organisms no longer removed carbon dioxide from the atmosphere, the rate of warming accelerated.
787129
the ozone deplation allows more rays to enter the earth's atmosphere.  Which then heats the atmosphere and raises the temps at the polar ice caps which melt.  The melted polarcaps will spill into the oceans that will spill over land.  Do you see where this is going.
1094442
Oxygen is the gas on which human respiration is dependant. There is a relative abundance of this gas in our atmosphere. Plants (which arrived on Earth before animals) were responsible for "polluting" the primeval atmosphere with this highly reactive gas (incidentally the same gas which forms ozone and screens us from deadly high energy radiation from the sun).\n\nI'll quickly run through the rest of the planets: -\n\n1. Mercury.\nHelium atmosphere which is almost nonexistent. Surface  temperatures vary between 350C (day) and minus 170C (night).\nVerdict: - instant death.\n\n2. Venus.\nAtmosphere has large quantities of sulphur dioxide (which smells like rotten eggs or a really bad fart!) and a constant rain of sulphuric acid. Pressure 90 times greater than the Earth's. Temperature of about 500C. Suspected that this is the effect of runaway global warming (heat trapped by carbon dioxide).\nVerdict: - Instant nasty death. The closest physical approximation to Hell.\n\n3. Earth.\nMmmmm. Nice.\n\n4. Mars.\nAtmosphere of mainly carbon dioxide. Atmospheric density fluctuates, but is never enough for liquid water to form in appreciable amounts. Mean surface temperature about minus 27C.\nVerdict: - Temperature and gravity are within tolerances for human life, but needs an oxygen and water transplant. No go (for the present).\n\n5., 6., 7., and 8. Jupiter, Saturn, Uranus and Neptune.\nThese are all termed "gas giants". They all have cores, but at depths within their atmospheres such that surface pressure is enormous. Temperatures of between minus 150C (Jupiter) and minus 220C (Neptune).\nVerdict: - All non-starters.\nAs a piece of trivia, Saturn is the only planet which is less dense than water, which means that if you could find a big enough basin of water, it would float!\n\nAnd finally (phew!) 9. Pluto.\nSmaller than the moon. No atmosphere. Surface temperature minus 230C.\nVerdict: - Waste of time and space. Not even worth the term "planet". There are bigger moons than this! Ours for a start!\n\nThe combination of a planet's density and size affect its gravitational attraction. If Earth were denser or larger, its gravitational attraction would increase (ie// you'd weigh more).\nMercury is about the size and density of the moon, so you could probably jump about 10-20 feet in the air quite easily. Mars is less dense but larger than Mercury, and has comparable gravity. Venus is about the same as Earth. Jupiter isn't dense, but could hold about 1,000 Earths, so its gravity is too high for us. The other gas giants, for all their size, are appreciably less dense than Earth, and have gravities not much greater than Earth. And Pluto's so small and insignificant that I reckon if you jumped you could possibly end up in orbit around it.\n\nEarth is the ONLY place in the entire Universe that we know of which has conditions which can sustain life of any sort. If we play a part in altering the atmosphere on this planet the Earth will still exist.It just might not be suitable for life.\n\nFurther answer to your additional response bit: -\n\nIf an astronaut removed his helmet on any planet except Earth he would die almost instantly.
206878
It is possible for the earth to hold an atmosphere due to its gravitational field.  All objects (of any size) are attracted to other objects (of any size) this is called gravity.  The earth's gravitational field therefore holds the oxygen, nitrogen, etc. inside its gravitational field because due to its size its gravity pulls the oxygen molecules to it.  This is also reason why there is more oxygen air etc.  at sea level than in the mountains.  As you ascend higher the gravity is less than at sea level so less air is held by gravity.
63093
Global warming is an effect in the earth's lower atmosphere that is claimed to exist by many scientists today.  Essentially, the theory claims that carbon monoxide, fluorocarbons and other gases have damaged the ozone layer, the protective layer in the earth's upper atmosphere that protects the planet from the Sun's ultraviolet (UV) radiation.  Some man-made causes of these gases are automobile emissions and bovine flattulance.  The supposed increased levels of UV radition are striking the earth in greater incidence, especially in the equatorial oceans. Hence, according to the theory, the warming oceans are changing weather patterns and melting the polar ice caps.   More severe storms and raising of the ocean levels are possible.  Detractors of the theory contend, however, that evidence for diminishment of the ozone layer, warming of the oceans and melting of the polar ice caps is scant due to the lack of longitudinal (long-term) climatological data for the earth.  In sum, it is unclear whether the changing weather patterns that appear to be happening are caused by man-made activities or part of some cycle governed by normal processes.
1123212
Not a very well phrased question.  But dissolved CO2 and O2 in water are primarily from the lifeforms inhabiting the water, such as plants, bacteria, and others.  Inorganic chemical reactions (such as volcanic activities) would also contribute to the changes in O2/CO2 balance.
569397
Environment pollution is pollution of water, air, soil, noise, light , visual and radio active .\n\n Pollution is the release of chemical, physical, biological or radioactive contaminants to the environment. Principal forms of pollution include: air , water....\nAir pollution is a broad term applied to any chemical, physical (e.g. particulate matter), or biological agent that modifies the natural characteristics of the atmosphere. The atmosphere is a complex, dynamic natural system that is essential to support life on planet earth. Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the earth's ecosystems.\n\nWorldwide air pollution is responsible for large numbers of deaths and cases of respiratory disease. Setting of air quality standards, such as the U.S. Clean Air Act, has begun to improve air quality for some pollutants. While major stationary sources are often identified with air pollution, the greatest source of emissions are actually mobile sources, principally the automobile. There are many available air pollution control technologies and urban planning strategies available to reduce air pollution; however, worldwide costs of addressing this issue are high. The most immediately available method of improving air quality is adoption of greater use of ethanol fuel (and other bio fuels) and increased reliance upon hybrid vehicle technology.\n\nYou can check out more your self.\nAir pollution :
626734
The greenhouse effect refers to the fact that Earth is surrounded by an atmosphere which acts like the transparent cover of a greenhouse, allowing sunlight to filter through while trapping heat.\n\nGreenhouse gases are trace gases of mainly water vapor, carbon dioxide, methane, ozone, and nitrous oxide. The Earth's atmosphere largely consists of nitrogen and oxygen, but these gases do not hold heat so they are not greenhouse gases nor contribute to the greenhouse effect.\n\nDuring the day the Earth absorbs heat from the Sun and re-radiates it back out to space. Normally this heat would escape each night and the temperature would fall rapidly. Instead, gaseous molecules absorb the heat given off by the planet, and re-radiate it out in all directions, reabsorbing it, and redistributing it again and again. This keeps the Earth's surface relatively warm and the average temperature comfortable. The greenhouse effect is key in Earth's ability to stay warm and sustain life.\n\nA look to our neighboring planets of Venus and Mars shows what happens when the greenhouse effect - which is akin to a blanket covering the planet - becomes too thick or too thin. Temperatures on Venus soar because of its very thick blanket or atmosphere. The runaway greenhouse effect here is staggering. Mars on the other hand has such a thin blanket (atmosphere) and a weak greenhouse effect, that the planet is very cold. Nearly all of the heat that reaches Mars escapes. Relative distance from the Sun plays a part in the global temperatures of the inner planets, but a greenhouse effect, or lack thereof, is largely responsible for the climates on all these planets.\n\nScientists started using the term "greenhouse effect" in the 1800's. At that time it had no negative connotation. In the mid 1950's the term "greenhouse effect" began to be associated with global warming and also with the negative effects of our industrial age. This enhanced greenhouse effect, as it's sometimes referred to, is the result of burning fossil fuels. This releases additional carbon dioxide into the atmosphere at the rate of about 3 gigatons (3 billion metric tons) per year. Since carbon dioxide (CO2) absorbs heat, we can expect that significant increases in CO2 will tend to raise the global temperature, possibly contributing to global warming. Simply put, if greenhouse gases act like a blanket to keep our planet warm, we are thickening that blanket.\n\nThe natural greenhouse effect on Earth is responsible for life as we know it. We may, however, need to become better stewards of our greenhouse gases in order to preserve life.
310306
Climate is affected by a number of sources such as where your location is to the equator, the earths rotation, etc. Long term changes are taking place very slowly due to human activities (gases, deforestation, soil erosion etc) and need to be addressed on a global level to prevent further changes. Increased gases in the atmosphere cause heating...and deforestation and decrease of plant life means that many of the carbons are not being used - so they continue to increase in the atmosphere causing changes. \nThere is no way to "stop" it, just slow it by us being more energy efficient, stop creating so much pollution...\nYou can somewhat effect microclimates - a local area that is changed because of large cities, large mountains etc - but not really hard to do intentionally - it's done over time as something builds up and disturbs the existing temp.\n\nWhew...that was a long one.
781652
[edit] Atmospheric convection\nIn the case of Earth's atmosphere, solar radiation heats the Earth's surface, and this heat is then transferred to the air by convection. When a layer of air receives enough heat from the Earth's surface, it expands, becomes less dense and is pushed upward by buoyancy. Colder, heavier air sinks under it and is then warmed, expands, and rises. The warm rising air cools as it reaches the higher, cooler regions of the atmosphere and becomes denser. Since it cannot sink through the rising air beneath it, it moves laterally and then begins to sink. When it reaches the surface again it is heated, and is drawn back into the original rising column.\nSo the answer is D
853505
life needs not only oxygen but othere conditions as well. Life needs essentailly he fore of gravity for the proceses of life to be active .It is graiy tha keeps the sir balanket over the surfaxce oif he earth . But for that , the air would vanish into thin air ! - would anish into space . Water would not flow and our food would not go doen  our throat and would not even be able to defecate . aain the climate is also imporant . We hae go to be at a distncefrom the dun hat would be expose us to a ligh and heat that is cinsucive to the development of live and tolerable to life .ALL  he planets around the sun are not locaed at a sistance very conducive to the deelopmemt of life like us .and all of hem dfo not hav a gaviy  tha is suitable for the fuctioning of our system . We are not independent of our great mother earth. We will not survive in any planet which dose not hae an amospher  and gavity like the earth. Oxygen alone won't  help us live .Since the building blocks of all elemens ar the same - electron and proton - we would be able create oxyen in any planet by a suiable process that man would be able to create by manipulaing the numbver of electrons in the aoms of any subasance aailable in any pkanet . We do not hae to transfer oxygen anywhere . we can create oxygen from   whatever is available anywhere.
149703
first of all, u should know that the quality f air is fast deterioting. with the increase in human populatin and the decrease in tree population, the % of CO2 will increase also. since we still using hidrocarbon for cars, power plant to generate electricity, etc the air is filled with CO2. with the increase in CO2, ur earth get warmer and ice is south n North pole will melt (green house effect). remember that the ice reflect sunlight to space, meaning our earth will even get warmer. other pollutants will not affect too much to our earth.
218542
You have to remember plants did not cause the atmosphere to become oxygenic in the primordial days, cyanobacteria did. I'm guessing there are probably trillions of trees in the world.
389547
do u mean the substances in the atmosphere?\n\nif so than the signgle most important part that keeps us from the bad influence of UV and Infra red radiance is the Ozone, which comprises the ozone layer.\nCertainly the other gasses that form the atmosphere on the earth are important because they form the atmosphere without which we would freeze during nights and melt during days.\nthose are the gases like N2 and O2
1087334
I assume you mean for humans.\n\nAir (particularly Earths air mixture of oxygen, carbon and nitrogen), Water, and plants. We couldn't survive long if any of the three did not exist.
396636
water, the oxygen and the abundant food. these are basic things that human being need on the earth.so all these can be found on the earth..water from rivers.oxygen from the air and food from fruit/trees, animals etc etc.
1157986
Naturally.  As long as pollution continues, the world logically will be more polluted every day.  The population grows exponentially, most of that population acquires a car, resulting in air and noise pollution.  The many natural disasters to recently grip the world (the Indian Ocean tsunami, Hurricane Katrina, etc.) massively increase pollution by rupturing and spreading sewage pipes.  As more fuels are burned, acid rain is made, heavily polluting the water, along with runoff from more construction sites and pollutants from factories.  This in turn affects groundwater, polluting the soil.  As all of these causes increase with the population, so will pollution.