David Attenborough confessed regret over brother before tragic passing: 'I'm sorry'

Sir David, 95, returns to screens tonight with his new BBC series, The Green Planet, presenting a guide to the lives of plants in environments around the world In the first episode, Tropical Worlds, he gives viewers a unique insight into the world of the tropical rainforests. New filming techniques offer aspects of the natural world on its own timescale, and features fast-growing trees, flowers that mimic dead animals, and life and death battles to absorb much-need sunlight.

The life-long naturalist and broadcaster has created some of the most memorable nature documentaries ever to hit screens. Many of them, like the Blue Planet series, have stirred national conversations about the environments we live in and how we treat them. Such is the extent to which he has lived, Sir David has often reflected on his work and his personal life, and also those close to him. One of these reflections came in 2014 on the death of his actor, Richard Attenborough.

Three years his senior, Richard and Sir David shared a close relationship throughout their lives. Known to modern generations for his role as John Hammond in Jurassic Park, Richard's passing was mourned across the country. At the time, Sir David admitted he was sad that his brother had not appeared in more comedies to show audiences just how funny he was. Richard had studied for his career in acting at the Royal Academy of Dramatic Art (RADA), and performed during the war after training as a pilot. JUST IN: Gary Burgess dead: ITV star dies in his sleep age 46

Many of his films were hard-hitting and serious, like The Great Escape where he starred as RAF Squadron Leader Roger Bartlett ("Big X"), and Guns At Batasi, for which he won the BAFTA Award for Best Actor for his portrayal of Regimental Sergeant Major Lauderdale. In an interview with the Radio Times shortly after Richard's death, Sir David said: "The thing that I'm sorry about is that actually Dick was a marvellous comic actor. "He was very, very funny, and could be - and was - in domestic circumstances. "We just spent all our time roaring with laughter - and that didn't get much of an outlet in his feature films. "I mean, Christmas time, you know, we just sat around, roaring with laughter." David Attenborough heartbreak after losing beloved wife [REPORT]

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Richard was 90 when he died. Meanwhile, Sir David's newest nature venture will take viewers across different environments in five-parts. After Tropical Worlds, he will explore Water Worlds, Human Worlds, Seasonal Worlds and Desert Worlds. The series is said to have been a great passion project for Sir David.

It is just one in a string of projects that he has committed to in a bid to sound the alarm for action against the climate crisis, including his work with Prince William's Earthshot Prize. In 2020, Netflix released the documentary, A Life On Our Planet, exploring Sir David's life and work, and the evolutionary history of life. Speaking about the documentary in an interview with 60 Minutes, he revealed just how hard it was for him to appear on the programme and revisit some of the potential climate catastrophes, many of which had since come true. He said: "Even the biggest and most awful things that humanity has done pale into insignificance when you think of what could be around the corner.