Sir David Attenborough smiled from ear to ear after he was awarded his Knight Grand Cross honour from fellow avid environmentalist Prince Charles.The 96-year-old presenter and all-round national treasure has been a household name across Britain and beyond for decades, having produced and presented world-famous nature documentaries for over 50 years.On Wednesday, the natural historian collected his Knight Grand Cross of the Order of St Michael and St George for his services to television broadcasting and conservation.Sir David, first knighted by the Queen in 1985, collected the prestigious honour from the Prince of Wales, eldest son of Her Majesty, at an investiture ceremony at Windsor Castle.His latest achievement comes after the biologist featured in a segment of the Platinum Party at the Queen’s Jubilee concert held outside Buckingham Palace in London on June 4.Prince William highlighted the efforts of ‘visionary environmentalists’ during a section of the show, which saw a clip of Sir David projected onto Buckingham Palace.In recent years, Sir David More pleaded with politicians and people in power to do everything possible to protect the planet, warning of climate change and mass extinction.Ahead of last year’s Cop26 climate summit in Glasgow, Sir David called for ‘bold action’ and support for local communities and landowners so they can create connected wild places on land and at sea to protect humanity.In comments carried by the BBC, Sir David used his being named as Champion of the Earth to again urge action to prevent further destruction of the planet.‘Fifty years ago, whales were on the very edge of extinction worldwide,’ he said.‘Then people got together and now there are more whales in the sea than any living.