How are carbon dioxide levels affecting the atmosphere?

Answer 1

The amount of CO2 in the atmosphere is increasing each year. We have stations carefully tracking CO2 concentration changes. The value swings up and down seasonally, as northern hemisphere plant foliage dies in the fall and begins growing in the spring and summer. But the overall trend is upward, as humans pump more CO2 into the air each year from fossil sources than the earth can absorb.

CO2 naturally rises and falls, and over the past 800,000 years the levels have varied from 250 to 290 ppm, generally swinging up or down about 5 ppm per thousand years. 7000 years ago CO2 was at 260 ppm. By only 5000 years ago it had risen to 270 and it was at 280 ppm 3000 years ago.

In 1700 it was again at 280 ppm, but by 1900, in just two short centuries, it rose to 290 ppm. That was 10 times faster than the natural historic change. Still, not a huge concern. At that rate of growth we would not have exceeded 350 ppm (what many scientists consider a maximum sustainable level) for centuries to come.

But we began increasing our consumption of fossil fuel, so that from 1900 to 1950 CO2 rose another 10 ppm, to 300. By 1958 it had risen to 315 ppm--15 ppm in under a decade, and it has continued accelerating in the intervening decades. We are now pushing 400 ppm, and will exceed 500 ppm before 2050.

Answer 2

Carbon dioxide (CO2) is one of the gases which keep the atmosphere (and the world) warm through the greenhouse effect. Since the Industrial Revolution carbon dioxide levels have been increasing in the atmosphere from 270 ppm (parts per million) to the present 393 ppm levels. This more than 40% increase is largely due to the burning of fossil fuel (coal, oil and natural gas) and deforestation (cutting down trees which previously removed CO2 from the atmosphere).

These levels of carbon dioxide and other greenhouse gases are causing the atmosphere to warm. This warming makes the earth and the oceans warmer as well, and is called global warming.

A:Carbon dioxide (CO2) levels are believed to be increasing in the atmosphere. The change claimed is about 0.01% worst case. The rest of the atmosphere remains unaffected. It is believed that this type of increase could be responsible for a portion of the 0.78 degrees of warming the planet has experienced since 1850. The exact proportions is in debate and is unknown.

Answer 3

Concentrations of carbon dioxide in the atmosphere have been rising since the Industrial Revolution, 200 years ago. This year (2013) carbon dioxide levels in the atmosphere reached 400 ppm. At the beginning of the Industrial Revolution they had been 280 ppm for thousands of years.

Answer 4

The % of CO2 in the atmosphere is increasing.

Answer 5

Carbon dioxide levels are rising in the atmosphere. Two hundred years ago CO2 measured 280 ppm (parts per million). Now they have reached 400 ppm.