Population Matters, an organisation that aims to “create a wave of public awareness and corresponding policy action on overpopulation and unsustainable consumption”, praised the couple for only having two children.
The charity described Harry and Meghan’s decision as “enlightened” and said they acted as a “role model for others”.
In a statement, Population Matters said: “Having a smaller family reduces our impact on the Earth, and provides a better chance for all our children, their children and future generations to flourish on a healthy planet.
“We commend the Duke and Duchess for taking this enlightened decision and for affirming that a smaller family is also a happy family.”
The couple will receive £500 to donate to a charity of their own choice.
In the past, Harry and Meghan discussed their decision to have a smaller family.
In 2019, they told Vogue that they didn’t want to have more than two children. They said: “We should be able to leave something better behind for the next generation.”
Earlier this year, the couple welcomed their second child. The baby girl was named after her great-grandmother Queen Elizabeth, and her grandmother Princess Diana.
A statement announcing her birth read: “It is with great joy that Prince Harry and Meghan, The Duke and Duchess of Sussex, welcome their daughter, Lilibet “Lili” Diana Mountbatten-Windsor, to the world.
“Lili was born on Friday, June 4 at 11:40 a.m. in the trusted care of the doctors and staff at Santa Barbara Cottage Hospital in Santa Barbara, CA.
“She weighed 7lbs 11oz (3.5kg). Both mother and child are healthy and well, and settling in at home.”