Has Earth's atmosphere always had the same composition?

Answer 1

the % of gases present now and before are not the same there is a wide difference in them. the temp also varies along time amount of raw materials also had changed a lot from stone age to present age

Answer 2

The Earth's orbit is not a perfect circle but an ellipse with the Sun at one of the foci. The point at which Earth is nearest the Sun (periapsis) moves a little bit each year. This is called "apsidal precession", and for the Earth it takes about 112,000 years to make a complete cycle.

Even beyond that, though, it changes very slightly due to the gravitational influence of the other planets, Jupiter in particular. This effect isn't large, but it's there.

Answer 3

The composition of the atmosphere is changing today as it has been changing since the earth began to cool and atmosphere formed, just as the climate has gone through periods of heating and cooling. There have been multiple "ice ages", and multiple thawings. Ocean levels have gone up and down. Carbon dioxide has been absorbed by plants and buried for centuries, and carbon dioxide levels have gone back up following volcanic eruptions.

Lately, (in the last hundred years) the levels of carbon dioxide has gone up. Scientists believe that pollution from human activity is changing the atmosphere.

• Burning of fossil fuels (coal, oil and natural gas) in industry, transport and the generation of electricity, which releases carbon dioxide (CO2).
• Bad agricultural practices emit methane (CH4), a powerful greenhouse gas.
• Deforestation has removed the trees that used to take carbon dioxide from the atmosphere.

Answer 4

The earliest atmosphere was mostly hydrogen, with some oxygen and carbon dioxide.

It gradually changed from time to time, sometimes with mostly nitrogen, till it settled about 2 billion years ago with more oxygen, gradually moving to the present composition of 77% nitrogen, 20% oxygen, 1% argon, 1% water vapor and 0.039% carbon dioxide, and small amounts of other gases.

Answer 5

No. The earth's atmosphere has not always had the same composition. At one time it did not contain oxygen. The minerals that formed could not have formed in the presence of oxygen. As a result, scientists are certain that it did not contain oxygen.

Answer 6

No, the surface changes. Erosion from rain and wind will gradually make mountain ranges lower; continents move; this movement creates new mountains, as the continental plates push against each other. For example, several million years ago, most continents were together, in one supercontinent, "Pangaea". I suggest you read an encyclopedia (e.g., en.wikipedia.org) article about plate tectonics; also about Pangaea or Pangea.

Answer 7

Yes, the Earth's orbit is an ellipse. We are closest to the Sun on January 4th and farthest at July 4th. The difference in distance is negligible compared to the distance to the Sun and does not affect us significantly.

Answer 8

Yes. It does not change much with altitude. CO2 exchanges with the contents of the ocean, but not O2 (in general). Additionally, the atmosphere changes with locale, where contaminants are added / removed.

Answer 9

No, it has changed over time. The original atmosphere of the Earth was mostly carbon dioxide with some water vapour, ammonia and methane, and was probably formed by volcanic outgassing. Living things introduced oxygen, and were one of the causes of reduced carbon dioxide. The ammonia then reacted with the oxygen.

Answer 10

No, the surface changes. Erosion from rain and wind will gradually make mountain ranges lower; continents move; this movement creates new mountains, as the continental plates push against each other. For example, several million years ago, most continents were together, in one supercontinent, "Pangaea". I suggest you read an encyclopedia (e.g., en.wikipedia.org) article about plate tectonics; also about Pangaea or Pangea.

No, the surface changes. Erosion from rain and wind will gradually make mountain ranges lower; continents move; this movement creates new mountains, as the continental plates push against each other. For example, several million years ago, most continents were together, in one supercontinent, "Pangaea". I suggest you read an encyclopedia (e.g., en.wikipedia.org) article about plate tectonics; also about Pangaea or Pangea.

No, the surface changes. Erosion from rain and wind will gradually make mountain ranges lower; continents move; this movement creates new mountains, as the continental plates push against each other. For example, several million years ago, most continents were together, in one supercontinent, "Pangaea". I suggest you read an encyclopedia (e.g., en.wikipedia.org) article about plate tectonics; also about Pangaea or Pangea.

No, the surface changes. Erosion from rain and wind will gradually make mountain ranges lower; continents move; this movement creates new mountains, as the continental plates push against each other. For example, several million years ago, most continents were together, in one supercontinent, "Pangaea". I suggest you read an encyclopedia (e.g., en.wikipedia.org) article about plate tectonics; also about Pangaea or Pangea.