An IMGW News Report
The Great Wall of China is often said to be visible from orbit. In truth, astronauts circling the Earth report that one of the most conspicuous human creations is far from Beijing or Giza. On Spain’s Mediterranean coast, Almería’s vast patchwork of plastic greenhouses gleams so brightly that it can be picked out from the International Space Station.
Covering more than 30,000 hectares – an expanse larger than the Isle of Wight – these structures form what locals call the mar de plástico, the “sea of plastic”. The roofs, made from reflective polyethylene, scatter sunlight with such force that they have altered the region’s climate. Studies using NASA satellite data show Almería has cooled by about 0.3°C per decade since the 1980s, even as the rest of Spain has warmed. The effect stems from a sharp increase in surface albedo: by reflecting nearly 10% more solar radiation than bare soil, the greenhouses act as giant mirrors to the sky.
“From space, the white expanse glitters as one of the Anthropocene’s most curious landmarks: a reminder that it is not monuments but agriculture that now marks humanity’s presence most indelibly on the planet”
From Orbit to Earth: The Scale of Spain’s Construction Project
- 3 million tonnes of produce each year
- A –0.3°C per decade cooling effect
- Around 30,000 tonnes of plastic waste annually
Scale brings abundance. Almería’s hothouses yield around 3m tonnes of fruit and vegetables annually – tomatoes, peppers, cucumbers and melons among them – making the province Europe’s winter pantry. Productivity per hectare is some 30 times higher than in open fields elsewhere on the continent. Much of the success rests on drip irrigation, hydroponics and biological pest control, methods that have become bywords for water-saving and pesticide reduction.
Yet abundance carries costs. The region’s aquifers, which provide around 80% of irrigation water, are increasingly depleted and polluted. Each year tens of thousands of tonnes of plastic sheets are replaced; while recycling rates are improving, illegal dumping persists, with fragments washing into rivers and the Mediterranean. Reports also highlight harsh conditions for migrant labourers, who often bear the hidden cost of Europe’s cheap produce.
The mar de plástico thus embodies a paradox. It shows how ingenuity can turn semi-desert into fertile farmland, cooling the climate in the process. It also demonstrates how food security built on fragile foundations – overdrawn aquifers, plastic waste and exploited workers – carries risks of its own.
From space, the white expanse glitters as one of the Anthropocene’s most curious landmarks: a reminder that it is not monuments but agriculture that now marks humanity’s presence most indelibly on the planet.
