Can our Earth Feed 10 Billion People?

Humanity has 30 years to find out.
ALL PARENTS REMEMBER the moment when they first held their children—the tiny crumpled face, an entire new person, emerging from the hospital blanket. I extended my hands and took my daughter in my arms. I was so overwhelmed that I could hardly think.
Afterward I wandered outside so that mother and child could rest. It was three in the morning, late February in New England. There was ice on the sidewalk and a cold drizzle in the air. As I stepped from the curb, a thought popped into my head: When my daughter is my age, almost 10 billion people will be walking the Earth. I stopped midstride. I thought, How is that going to work?
Today the world has about 7.6 billion inhabitants. Most demographers believe that by about 2050, that number will reach 10 billion or a bit less. Around this time, our population will probably begin to level off. As a species, we will be at about “replacement level”: On average, each couple will have just enough children to replace themselves. All the while, economists say, the world’s development should continue, however unevenly. The implication is that when my daughter is my age, a sizable percentage of the world’s 10 billion people will be middle-class.