Question

According to scientists, why doesn't the greenhouse effect warm Mars's atmosphere?

Answer 1

The solarradaiation is much lower than the Erth or Venus

Explanation:

The atmospheric pressure is only 1/100 that of earth that is about 7 milli bar. These two reason keep the effect of green house effect to a minimum.on Mars.

Answer 2

Mars is constantly loosing its thin atmosphere that once kept it warm and wet, rather than the cold, dry, barren planet it has become.

Explanation:

The reason for this phenomenon is the lack of a magnetic field on Mars. The magnetic field on Mars has depreciated to less than `1/100%`of that on Earth.

As a result a continuous blast of charged particles from the sun is striking the planet with no magnetic field to divert the particles away. The charged particles are removing the Martian atmosphere at a rate of `200g/sec.`

The Martian atmosphere consists of 95% carbon dioxide `(CO_2)`. This would normally keep a planet warm, as we are experiencing on Earth. But up on Mars the atmosphere is now too thin, and is gradually disappearing, so the heat is not held on the planet. The average surface temperature on Mars is `-63^0C` compared to Earth's `+14^0C`

The NASA Maven spacecraft sent back the data here:
http://www.bing.com/videos/search?q=ghg+on+mars&view=detail&mid=62AF5D6D997F6B719FE862AF5D6D997F6B719FE8&FORM=VIRE