Air quality is a measure of the pollution level in the air. Polluted air can be caused by many things. There are manmade and natural sources of emissions. 

The volume of data in a single file or file system can be described by a unit called a byte. However, data volumes can become very large when dealing with Earth satellite data. Below is a table to explain data volume units (Credit:  Roy Williams, Center for Advanced Computing Research at the California Institute of Technology).

In addition to the changes brought about by natural forces, it has recently become apparent that a relative newcomer to planet Earth — the human being — has become a powerful agent of environmental change.

The world's surface air temperature is getting warmer. Whether the cause is human activity or natural changes in the Earth System—and the enormous body of evidence says it’s humans—thermometer readings all around the world have risen steadily since the beginning of the Industrial Revolution. 

Background information on snow and ice extent.

Science educators strive to engage students in authentic investigations that have students analyze data in order to derive meaning.  MND provides unlimited opportunities to engage students in data analysis using Earth System data.