Paul Ehrlich update his early projections because his original ideas underestimated

Answer: The correct answer is : They underestimated the resilience of the global system

Explanation: Paul is a biologist from the United States well known for warning about the consequences of population growth and limited resources. His statement: The battle to feed all mankind is over. Affirming that in the 1970s they would starve to death despite the programs established to deal with emergencies. But this prediction proved to be incorrect.