Renowned naturalist and veteran broadcaster David Attenborough joined Instagram last week and quickly busted the record for the fastest time to reach one million followers with his inaugural post promising to use the platform to talk about solutions to the global climate and ecological crises.

"As we all know, the world is in trouble," the 94-year-old says in the video.

"Continents are on fire. Glaciers are melting. Coral reefs are dying. Fish are disappearing from our oceans. The list goes on and on," says Attenborough.

"But we know what to do about it. And that's why I'm tackling this new way, for me, of communication. Over the next few weeks I'll be recording messages to explain what the problems are and how we can deal with them," he continued. "Join me—or as we used to say... stay tuned."

It took Attenborough just four hours and 44 minutes to top the record that had been held most recently by actor Jennifer Aniston, according to Guinness World Records. As of this writing, Attenborough's Instagram account, which is being run by filmmakers Collin Butfield and Johnnie Hughes, boasts 4.7 million followers.

Butfield and Hughes worked with Attenborough on the film "A Life On Our Planet," which aims to give "a first-hand account of humanity's impact on nature and a message of hope for future generations." The film comes to Netflix October 4.

Attenborough's most recent Instagram post, shared Monday, includes a clip of the film. He prefaces the snippet by stressing that "we are also a part of nature."

"We should be in no doubt biodiversity loss, the destruction of nature, is as grave an issue as climate change," he says. "They both work together to destabilize the world we rely upon."

In an interview with "BBC Breakfast" that aired Monday, he talked about "A Life On Our Planet" and other issues including the waves of young climate protesters that have taken to streets worldwide to demand urgent action on the planetary crisis.

"It's as though people have woken up," said Attenborough. "And it's young people ...who have shaken our consciences."

As for his new record-topping Instagram account, he said that "the message that I'm concerned about is so important I would use any medium to get it out."

Attenborough welcomed the fact that young people "are on board" with his message, saying "that is the most important hope."

That's because "it's their world and it's their tomorrow. I wont be there; they will be." He added, "I feel privileged that they should listen to what an old bloke like me is talking about."

Despite the immense scale of damage humanity has caused the natural world, Attenborough told BBC that his determination to do something about the harm is unwavering.

"We have a responsibility," he said, "and if there's only a fragment of hope left, you have a responsibility to do something about it."