The film examines mainstream environmental groups' partnerships with billionaires, corporations, and wealthy family foundations in the fight to save the planet.

It was criticized by some climate scientists, environmentalists and renewable energy proponents as misleading and outdated,[7][8][9][10] but received praise for its contrarian stance and for provoking discussion.

In November 2020, Moore removed it from YouTube where it was available for free and made it available on Amazon, Apple and Google's rental channels,[14] although a copy remains on the Internet Archive.

[16] Planet of the Humans takes a critical look at the mainstream environmental movement, questioning its leaders' decision to partner with billionaires, corporations, and wealthy family foundations, and to promote renewable energy technology as the solution to climate change.

Gibbs interviews environmental sociologist Richard York, whose study in Nature, found that renewables were not displacing fossil fuels.

Zehner discusses how companies including Apple and Tesla claim to run on 100% renewable energy despite remaining hooked up to the grid, and describes the Koch Brothers' involvement in green technology production.

A three-minute montage shows the scale of industrial mining required for renewable technologies, and Gibbs describes how solar and wind arrays must be replaced after only a few decades.

A citizen activist in Michigan describes how her local biomass plant burns pentachlorophenol and creosote-treated railroad ties shipped in from Canada as well as rubber tires, which cause black snow to appear at the adjacent elementary school.

The section ends with Gibbs, as part of a media event at the Climate March in New York City, asking environmental leaders for their stance on biomass including Van Jones, Robert F. Kennedy Jr., Bill McKibben, and Vandana Shiva.

In the last third of the film, Gibbs explores the partnerships between mainstream environmental groups and Wall Street investors, billionaires, and wealthy family foundations.

Bill McKibben of 350.org is shown on stage with former Goldman Sachs executive David Blood, supporting his call to raise $40–50 trillion in green energy investments.

Gibbs displays U.S. Securities and Exchange Commission filings of green funds promoted in divestment campaigns by McKibben and the Sierra Club, which show holdings in mining companies, oil and gas infrastructure, various banks including BlackRock, as well as Halliburton, McDonalds, Coca-Cola, Exxon, Chevron, Gazprom, and Enviva among others.

He also shows Gore in multiple interviews defending his decision to sell his American television channel, Current TV, earning him an estimated $100 million pre-tax for the deal, to Al Jazeera, which is owned by the State of Qatar, an oil and gas producer.

Gibbs attends an Earth Day concert celebration in Washington, DC sponsored by Toyota, Citibank, and Caterpillar, where Dennis Hayes claims the entire event is run on solar energy.

The film ends with Gibbs reflecting that "Infinite growth on a finite planet is suicide", imploring the audience to take back the environmental movement from billionaires and capitalists.

[20] In an interview held at TCFF, Gibbs stated that "the film is not expected to be a comfortable beginning to the needed conversation", especially for those who treat solar and wind energy like "sacred cows".

[25] On May 25, 2020, the film was temporarily removed from YouTube due to a copyright infringement claim by British environmental photographer Toby Smith over a 4-second segment Gibbs considered fair-use content.

[8][9][28] The film claims the carbon footprint of renewable energy is comparable to fossil fuels, when taking into account all different stages of its production.

[29][30][31] The film uses footage of a solar field that is up to a decade old, which critics argue may give a false impression of the maturity of the technologies in the present day.

[34][35][36] A pie chart is shown in the film with total battery storage compared to yearly energy use, which is a factor of thousand higher.

[37] In a letter, filmmaker and environmental activist Josh Fox and academics including climate scientist Michael Mann have asked for an apology and a retraction of the film.

They say the film includes "various distortions, half-truths and lies", and that the filmmakers "have done a grave disservice to us and the planet by promoting climate change inactivist tropes and talking points".

[46] Julie Ann Grimm of the Santa Fe Reporter[47] praised the film saying that "Gibbs highlights how the global environmental cost of mining, production and disposal of solar and wind technology don’t get primetime play" and calling it a "enjoyable if also gut-rotting indictment of Big Environment and some of its figureheads" concluding that "It's ... a must-watch".

[48] Adrian Hennigan, features editor at Haaretz,[49] called Planet of the Humans a "provocative documentary about how capitalism has destroyed the environmental movement" and stated: "This cri de coeur from American producer-composer-editor Gibbs may lack balance and counterarguments, but it convincingly makes the case that 'less must be the new more' if humankind is to have any chance of not being wiped out due to overpopulation and overconsumption".

However, they were less positive about the film's scepticism of companies, saying: "But the duo seem particularly aghast ... that any transition to green energy will require massive investment from evil industrialists and capitalists who might turn a profit.

[53] Dennis Harvey in Variety claimed "Gibbs' dull monotone makes him a poor narrator", "there's nothing particularly elegant about the way Planet of the Humans arrives at its downbeat thesis," and "though well-shot and edited, the material here is simply too sprawling to avoid feeling crammed into one ungainly package".

[31] The Post Carbon Institute, a sustainability think tank closely connected with interviewee Richard Heinberg, published a podcast that criticizes the film.

[58] Josh Fox of The Nation said that the film is "wildly unscientific, outdated, full of falsehoods, and benefits fossil fuel industry promoters and climate deniers.

"[62] Ted Nordhaus, an environmental policy writer and proponent of nuclear energy and industrial agriculture, argued that "the treatment of renewables [in the film] is a mirror image of the misinformation that the anti-nuclear movement has trafficked in for decades."

Monbiot further criticised the film's focus on discussions of overpopulation, saying: "When wealthy people, such as Moore and Gibbs, point to this issue without the necessary caveats, they are saying, in effect, 'it's not Us consuming, it’s Them breeding.