Question: Name the American actor, film producer and environmentalist activist who co-wrote the '11th Hour', a 2007 documentary film about the state of the natural environment, distributed by Warner Independent Pictures?

Context paragraphs:
Uncle Henry's Playhouse: Uncle Henry's Playhouse (released in the UK as Uncle Henry's MindBlower) is the third game in the "The 7th Guest" series.  Functionally the game is a compilation game mostly composed of the puzzles from Trilobyte's games "The 7th Guest", "The 11th Hour", and "Clandestiny", but featuring little plot.  The game has been noted for its low sales figures (27 in the US) and its rarity/obscurity relative to its blockbuster predecessors, "The 7th Guest" and "The 11th Hour".

Warner Independent Pictures: Warner Independent Pictures was an American independent film division of an American film studio Warner Bros., itself a division of Time Warner.  Established in August 2003, its first release was 2004's "Before Sunset".  The division financed, produced, acquired and distributed feature films largely budgeted under $20 million.

The 11th Hour (newspaper): The 11th Hour News Weekly is an arts and entertainment alternative weekly published in Macon, Statesboro and Valdosta, Georgia.  Beginning in Statesboro in 2001 as a newsletter on bars and nightclubs, it developed into a full-scale A&E publication, featuring leisure events in the college town.  In 2003, "The 11th Hour" opened a main office in Macon.  With its growing popularity, the newsweekly expanded distribution of the Macon version to the surrounding Middle Georgia cities of Milledgeville and Warner Robins.  Valdosta’s version of "The 11th Hour" began in 2004; its readers are students at Valdosta State University and other supporters of the South Georgia art community

The 11th Hour (2007 film): The 11th Hour is a 2007 documentary film, created, produced, co-written and narrated by Leonardo DiCaprio, on the state of the natural environment.  It was directed by Leila Conners Petersen and Nadia Conners and financed by Adam Lewis and Pierre André Senizergues, and distributed by Warner Independent Pictures.

Leonardo DiCaprio: Leonardo Wilhelm DiCaprio ( ; born November 11, 1974) is an American actor, film producer, and environmental activist.  DiCaprio began his career by appearing in television commercials in the late 1980s, after which he had recurring roles in various television series such as the soap opera "Santa Barbara" and the sitcom "Growing Pains".  He began his film career by starring as Josh in "Critters 3" (1991).  He starred in the film adaptation of the memoir "This Boy's Life" (1993), and was praised for his supporting role in "What's Eating Gilbert Grape" (1993).  He gained public recognition with leading roles in "The Basketball Diaries" (1995) and the romantic drama "Romeo + Juliet" (1996), before achieving international fame with James Cameron's epic romance "Titanic" (1997), which became the highest-grossing film of all time until Cameron's science fiction film "Avatar" (2009) overtook it.

A Scanner Darkly (film): A Scanner Darkly is a 2006 American animated science-fiction thriller film directed by Richard Linklater, based on the novel of the same name by Philip K. Dick.  The film tells the story of identity and deception in a near-future dystopia constantly under intrusive high-tech police surveillance in the midst of a drug addiction epidemic.  The film was shot digitally and then animated using interpolated rotoscope, an animation technique in which animators trace over the original footage frame by frame, for use in live-action and animated films, giving the finished result a distinctive animated look.  It was distributed by Warner Independent Pictures.

Remembrance Day: Remembrance Day (sometimes known informally as Poppy Day) is a memorial day observed in Commonwealth of Nations member states since the end of the First World War to remember the members of their armed forces who have died in the line of duty.  Following a tradition inaugurated by King George V in 1919, the day is also marked by war remembrances in many non-Commonwealth countries.  Remembrance Day is observed on 11 November in most countries to recall the end of hostilities of World War I on that date in 1918.  Hostilities formally ended "at the 11th hour of the 11th day of the 11th month", in accordance with the armistice signed by representatives of Germany and the Entente between 5:12 and 5:20 that morning.  ("At the 11th hour" refers to the "passing" of the 11th hour, or 11:00 am.)  The First World War officially ended with the signing of the Treaty of Versailles on 28 June 1919.

The Film Department: The Film Department (TFD) was an independent movie production, finance and international sales company based in West Hollywood, California.  The company was founded in 2007 by Warner Independent Pictures and Miramax president Mark Gill and former Yari Film Group COO and Miramax veteran Neil Sacker.

Spring Breakdown: Spring Breakdown is a comedy film starring Amy Poehler, Parker Posey, and Rachel Dratch.  Three years after principal photography, and after the film's owner, Warner Independent Pictures, was shut down by its parent company, it was released direct-to-video in 2009.

Clubland (2007 film): Clubland, internationally known as Introducing the Dwights, is a 2007 Australian comedy-drama film, directed by Cherie Nowlan, written by Keith Thompson, and starring Oscar nominee Brenda Blethyn and Emma Booth.  The film was nominated for eleven AFI awards, winning the award for best supporting actress for Emma Booth.  It sold to Warner Independent Pictures for $4.1 million, after debuting at Sundance Film Festival, where it gained standing ovations.  The film opened in the U.S. on 4 July holiday weekend, the first Australian film ever to do so.

Supporting paragraphs: The 11th Hour (2007 film) Leonardo DiCaprio
Answer: Leonardo DiCaprio