Just south of The Hague, in the Westland region of the Netherlands, miles upon miles of greenhouses are spread across the landscape. They have been built by Dutch farmers as part of a 20-year movement to pursue sustainable agriculture by growing indoors. In times of climate change the Dutch agricultural revolution seeks to move beyond greenhouses, which still rely on outside forces like sunlight. But it isn't cheap. "What really matters is if the income is larger than the cost", says Leo Marcelis, university professor at Wageningen University. Fueled by indoor farming, the country has become the second biggest food exporter in the world.