Carbon Dioxide

The effects of Climate Change in Space


The Effects of Climate Change

The effects of rising levels of carbon dioxide due to human activity leading to global warming are well documented. The impact includes increased extreme weather, melting polar ice caps and changes in weather patterns among others.  Less people realize some of the effects of climate change are not only being observed on the earth surface but in space as well.

Space – The Final Frontier

Space begins above an altitude greater than 6000 miles above the surface of the earth where there is no air. The lower at a distance in excess of 400 miles from the earth surface.

The problem is the Earth’s orbit is littered defunct satellites, spent rocket boosters, and other random debris. There are over 11,500 objects larger than 4 inches across.  The concern is one of these pieces of space junk could smash into a working satellite.

Atmospheric Layers

The atmosphere is known for having significant variations in temperature and pressure with altitude, which create layers. These include the troposphere (0 to 10 miles), stratosphere (10 to 30 miles), mesosphere (30 to 50 miles) and thermosphere (50 to 400 miles). The troposphere contains the air we breathe, all the planets moisture and water vapor, and is where the weather occurs.

Satellites orbit in the thermosphere where the air incredibly thin, yet still causes resistance in the orbit (or drag) on satellites. NASA routinely boosts the orbit of the space station as it is constantly degrading. Other satellites experience limited life spans in part because the thin air eventually drags them down.  Atmospheric drag can have catastrophic effects on items in space — for instance, drag increased on Skylab, the first U.S. space station, caused it to crash back to Earth.

Carbon Dioxide in Our Atmosphere

Near Earth’s surface, the air molecules collide frequently with other and the energy is released as heat, warming the air. The main effects of carbon dioxide come from its collisions with oxygen atoms. These impacts excite carbon dioxide molecules, making them radiate heat.  The density of carbon dioxide is too thin above altitudes of about 30 miles for the molecules to recapture this heat, which means it mostly escapes to space, chilling the outermost atmosphere. However, in the much thinner thermosphere, a carbon dioxide molecule has ample time to radiate energy to space because collisions are infrequent. The result is a cooling effect which results in the thermosphere settling causing a reduction of the air density at a given height.

In short, the increased carbon dioxide levels are causing a reduction of the air temperature in the upper portions of our atmosphere. Since the air is now denser satellites can stay aloft longer which increases their chances of collision.

Climate Change – unseen impacts

The scientist in me makes me think about what currently unseen effects of climate change will we stumble across in the future.