Good point. We're used to thinking of farming as a business and, as a business, dependent on efficiency and growth. Yet nature has neither. Plants already evolved to maximize efficiency and growth. Without human tinkering both efficiency (GMOs) and growth (fertilizer, land reclamation) would remain perpetually stagnant. With the introduction of climate change now REDUCING both efficiency and growth in natural systems, the hurdles we face in feeding a growing population become clear.