A Closer Look: Warming on Mars

Isn’t Mars experiencing global warming as well?

To answer a question with a question, does it matter?

If Mars is experiencing warming on a global scale, the only reason to discuss it alongside planetary warming on Earth is to attribute both warming trends to a common source, namely the Sun. However, as discussed in the related post, “Isn’t the Sun driving current climate change?”, the output of the Sun has not increased noticeably over the last 30 years of direct observation.

The discussion of solar climate forcing also detracts from the much more obvious fact that Mars is a completely different planet from Earth. Mars is a unique planet with vastly different compositions to its atmosphere, wind currents, orbital variations, rotational characteristics, weather patterns, and so on. In other words, at any given time, the Martian climate is exposed to forcings that are literally a world away from those impacting Earth. The two planets could be warming concurrently, cooling concurrently, or going in completely opposite directions based on purely natural influences. As a result, there is little validity in drawing a parallel between the two planets to deduce a cause of warming here on Earth.

Due to the vastly different composition of the Martian atmosphere, it is prone to massive dust storms that can greatly affect planetary temperatures. These dust storms also impact the albedo of the Martian surface, enabling the planet to retain more heat without a concurrent rise in solar output. And it is these atmospheric characteristics of Mars that are being found responsible for the recently observed melting of the polar ice caps on that planet.

Additional Reading

• Mars Express watches a dust storm engulf Mars – Space Spin (December 12, 2007)
• Some Coolness on Martian Global Warming and Reflections on the Role of Surface Dust – American Geophysical Union (AGU) (Fall 2007)
• Global warming and climate forcing by recent albedo changes on Mars – Nature (April 5, 2007)
• Global warming on Mars – RealClimate (October 5, 2005)
• Mars May Be Emerging From An Ice Age – NASA Jet Propulsion Labaratory (JPL) (December 17, 2003)