Almería: Are greenhouses keeping us cooler?

A significant fall in the air temperature of 0.3°C per decade in Almería, south-eastern Spain, during the period 1983–2006 has been reported for the first time in a new study led by Dr. Pablo Campra, a professor at the University of Almería, and published by the Journal of Geophysical Research.

 

In recent decades, hothouse farming has spread dramatically across the semi-arid province of Almería, creating a continuous area of 26,000 ha in 2007, the largest expanse of greenhouses in the world.

 

According to this study, which analysed surface shortwave radiative forcing (SWRF) data and trends in local temperatures, the recent development of greenhouse horticulture in this area may have masked local warming signals associated with an increase in greenhouse gas emission.

 

The local cooling trend shows no correlation with regional and global warming trends.

 

“It is not generally known that the increase in greenhouse gas emissions is not the only factor that can modify the climate of an area,” Dr. Campra observed, making reference to the white plastic sheeting of the greenhouses which push down local temperatures due to their ability to reflect sunlight. “This could buy us crucial time as we seek to stabilise and reduce the effects of greenhouse gases,” the researcher declared.