Prince William was grief-stricken and close to tears when he went to a heavily-guarded site on his visit to Tasmania. The trip, documented in the new program, Prince William: A Planet for Us All, changed his outlook about the state of the Earth now that he is a dad of three.

The Duke of Cambridge had cameras follow him for two years as he carried out the fight against illegal poaching. Prince William said that he realized he had to protect endangered species like the rhinoceros or elephants because these animals might be extinct by the time George, Charlotte and Louis are in their 20s.  

The royal's trip to this region in Africa brought him to a facility that had over 43,000 rhinoceros' husks. Prince William looked enraged by what he saw because it highlighted the gravity of the situation. 

Prince William said in the documentary that he could not get his head around what poachers do because husks or tusks are equivalent to fingernails in humans. He said that, while these animals might look odd, big and bulky, they are still vulnerable creatures that try to exist and keep their family together in the herd. They also have mothers in the pack who need to protect their children from these illegal traders.

The Duke of Cambridge said that poachers take advantage of rhinoceros because they do not have sharp eyesight. The royal has been speaking against this illegal act even before he got married and had kids.

However, Prince William said that something has to be done about the destruction of the Earth's resources. He urged the viewers to pick up the pace and get on top of the problem as it will matter to the children's future. 

The Duke of Cambridge said he felt it is his duty to be involved in environmental issues so he could leave the planet in a better situation for the future generation. He acknowledged that both his grandfather, Prince Philip, and father, Prince Charles, have been ahead of their time when it came to their work for the environment. 

The second in line to the throne said that he didn't want a 20-year-old Prince George asking him one day about what he has done or if he is ahead of his time. 

"If [George] does [ask], then we are too late," Prince William said. 

The documentary aired on ITV in the U.K. on Oct. 5.