Last Night's TV: What the Green Movement Got Wrong/Channel 4<br />Ego: The Strange and Wonderful World of Self-Portraits/BBC4

There's almost nothing so delicious on the small screen as a hippy eating humble pie; except maybe a whole parade of them, exhibited over an hour, and packed into a documentary prosecuting the intellectual crimes of a pressure group who claim to speak for the zeitgeist. I don't know if whoever was behind the treatment for What the Green Movement Got Wrong is freelance or on the staff at Darlow Smithson, the production company, but if he or she is the former, there's a memo that urgently needs sending from the executive suite this morning, with annual contract attached.

The show is already causing a stir. Adam Werbach, the American former president of the Sierra Club, a conservation group, says the programme makers misrepresented him. Channel 4 denies the claim, as they do Greenpeace's accusation that they were "lied to".

Werbach would resist the charge of "hippy"; but most of the others featured here – from authors Mark Lynas and Stewart Brand to Patrick Moore, a founder of Greenpeace who left it in the 1980s because he felt the group had become "anti-science" – would smile knowingly at it. The merit of the show was its use of these authorities to elucidate what has, absurdly, become a heretical position: pro-environmentalism, but anti the Green movement. Hugely controversial issues – GM crops, nuclear fuel, over-population – were examined in turn. With each, one of our ex-hippies said: maybe we Greens got this wrong.

Lynas walked around the derelict plant at Chernobyl. The disaster here had been a formative event in his adoption of the Green cause as a child. He had all the wide-eyed curiosity of a toddler in a zoo, and when talking to the author of a UN report on the disaster, was charmingly receptive to the fact that environmentalists had massively exaggerated the number of fatalities caused by the accident of April 26 1986.

Brand then confessed his sorrow over the mis-adoption by environmentalists of Rachel Carson's Silent Spring, in which that author alerted the world to the dangers caused by pesticides. She didn't say ban the lot; but some greens pretended she did. Yet the banning of DDT, a notorious pesticide, led – in Brand's words – to the preventable deaths of millions through malaria.

Along with Patrick Brand also addressed the issue of nuclear power stations. The success of the Green Movement, especially in America, in preventing the building of new nuclear power stations led instead to a massive expansion of coal power stations – which release carbon dioxide on such a scale as to now be a chief target of the Greens' invective.

These cases came together to form a cogent argument. Debates over climate change provide as many wrong questions as wrong answers, and tend to apportion the label of "denial" to anyone who speaks heretically. But for the purposes of public argument, heresy and humility are always desirable, and when the facts change, we should change our minds. That's what these guys did. They still think that climate change is real, and that the marriage between finite resources and infinite demands must end in divorce. But they think that the relationship has been soured already by some on their own side. They accept the stubborn appeal of Malthusianism; but they find distasteful the eco-imperialism that seems its constant bedfellow. Indeed, when the Indian environmentalist Sunita Narain piped up to ask who the hell affluent Westerners thought they were in telling poor people not to eat GM food, you knew that there was a winning moral force behind the scrutiny this programme displayed.

Introspection was the theme of the evening. In the second outstanding documentary, Laura Cumming, art critic of The Observer, devoted an hour and a half of prime time and a lot of air miles to the history of self-portraits. Ego: The Strange and Wonderful World of Self-Portraits was stunning, unashamed high-brow television from first minute to last.

Much like John Berger years before, Cumming has an accessible enthusiasm for her specialist subject, talking evocatively about art without being patronising. Starting with Albrecht Dürer, the German who portrayed himself as Christ at the turn of the 15th century, and working through over a dozen great artists, from Rembrandt, Courbet and Van Gogh to Messerschmidt and Warhol, Cumming showed how the evolution of self-portraits reflected the evolution of broader cultural and philosophical trends.

The unique virtue of self-portraits, Cumming explained, is they show artists representing themselves both in and as a work of art. By looking at self-portraits, we see what the artists themselves saw, and so look momentarily at the world as they did. And they convey how the artist wanted to project themselves into the world, and be remembered.

Particular glories were Van Gogh's declaration that he would "revolutionise portraiture" before promptly doing so, and those extraordinary "character heads" Messerschmidt produced when feeling in the grip of a ghost he called "the spirit of proportion". Cumming's finale, a charming anecdote about her artist father's only self-portrait, suggested she was in the grip of something similar; and frankly, after 90 engrossing minutes, I felt like I was too.