People often say to me 'we can't feed the population with organic farming.' Not being brave enough to back myself or quick enough to remember the numbers, I might answer: 'if we lose ecosystems there will be no food at all'. However the dramatic depletion in biodiversity over the last 80 years, in large part caused by industrial agriculture, is not tangible or easily recognisable, unless you have witnessed, for example, hand pollination of apples in the absence of sufficient insects. My answer also does not present a solution. So I checked the numbers.
There are 7.8 billion people in the world. 1 billion are undernourished, whilst 2 billion suffer from 'diseases of affluence' (e.g. 400 million with diabetes). We produce 2.5 billion tonnes of cereal per year. 1 tonne of cereal can supply three people with enough macronutrient (food energy and protein) for a year; so 2.5 billion tonnes is enough for 7.5 billion people. Cereals make up less than half of our food, with the rest (including many micronutrients) coming from pulses, root and stem tubers, seeds, nuts, fruit, vegetables, meat, eggs, dairy, fish, etc. As such we easily produce enough food for 15 billion people. 48% too much. Short term macroeconomics require us to consume in order to prevent employment from falling, and yes, food waste, global trade, logistics, human behaviours and politics are complicated. But when global food production output per capita has outpaced global food demand for at least a decade, and growth in obesity and malnutrition indicates that global production is not meeting nutritional needs, why are we all still convinced that we need to produce more of the same food?
Average organic yields are 10-30% less than 'conventional' depending on sector, soil type, etc. The transition away from chemicals towards high yielding, healthy soils cannot be made overnight, therefore, let's make the conservative assumption that organic farming can only produce a third of what is produced using chemicals. On that basis, if we were to increase the organically farmed area from the current 1.5% to 50% (replacing conventionally farmed area), there would still be enough food for well in excess of the global population predicted for 2050.
In short, organic farmers cannot feed all of the population based on its current demands. However, no more people will starve if up to half of agricultural land is farmed with zero chemicals. We can prevent the natural world from collapse - and in doing so, save ourselves.