Plant growth is declining all over the planet and the world is becoming less green, according to new research.

The authors of a new study appearing the journal Science Advances points to satellite observations that revealed expanding vegetation worldwide during much of the 1980s and 1990s. 

But the trend stopped about 20 years ago.  In those two decades, more than half of the world’s vegetated landscapes have been experiencing a "browning" trend of decreasing plant growth.

As man-made conditions cause global warming, the authors say rising temperatures result in something called a vapor pressure deficit.  That's the difference between the amount of moisture the air actually holds versus the maximum amount of moisture it is capable of holding.  A high deficit is sometimes referred to as an atmospheric drought.

Models produced by climate scientists project that vapor pressure deficits will continue as the world warms, and the pattern "might have a substantially negative impact on vegetation".

The new research bolsters a 2010 study appearing in the journal Science which also noticed a decline in plant life since the 1990s and said that water issues likely played a role.