Terrestrial Earth: The Power of the Planet BBC2, 9pm Oceans are more than huge reservoirs of water. Their brute force carves the coastline. They transfer energy around the planet and drive the climate. Dr Iain Stewart visits Hawaii, where he shows how the oceans capture and store energy from the wind, eventually delivering it to the coastline and creating some very powerful waves. Splash!

Sex in the Noughties: The Blog Girls Channel 4, 10pm In 2004, there were 20 million blogs on the interwebulator. Many of those attracting massive readerships were anonymous, confessional sex diaries written by women. One British lady's brand of frank filth captured millions: Girl with a One-Track Mind. Now she lifts the lid on the secret world of the cyber-muck-peddlar, thereby charting the rise and fall of an online phenomenon.

Death Race 2007: Tonight ITV1, 10pm Dopey YouTube yobboes are staging illegal stunts on our roads that potentially put lives at risk. Take the 20-year-old who was sentenced to four months in jail and a three-year driving ban for filming himself on his mobile as he raced down the M65 at 140mph, overtaking vehicles on the hard shoulder. Police arrested him after seeing the footage posted on the internet. Reporter Quentin Willson reveals the young twerps behind such internet footage and investigates what the police are doing to stop them. British Touring Car legend Jason Plato also evaluates how safe they are on our roads, with predictably startling results.

Digital 21 Grams Film 4, 9pm Director Alejandro Gonzalez Inarritu follows Amores Perros with his first film in English. As in Amores Perros, Inarritu plays around with linear structure and the conventions of narrative (making for a bitty opening that you need to stick with for your ultimate movie-going reward). The action centres on Paul Rivers (Sean Penn), a professor of maths with a weak heart. His wife, Mary (Charlotte Gainsbourg), wants to have a child her husband may never see. Jack Jordan (Benicio Del Toro) is an ex-con who has found Jesus but still slips into his old ways. Christina Peck (Naomi Watts) is a happily married suburban wife and mother until a traumatic event sends her back to her old life of drugs. As their lives emerge via gritty vignettes, Inarritu slowly brings them together in a climax of tragedy and redemption.

Flight of the Conchords BBC4, 9.30pm The season of deadpan comedy delight ends with clueless manager Murray foisting a new, bongo-playing band member on Bret and Jemaine. This triggers angry dancing and mutant half-bands.

How Is Your Fish Today? More 4, 10pm A multiple-award-winning documentary from the True Stories strand of programmes which concerns a scriptwriter. He writes a fictional story set in a remote, snowy village between China and Russia. Upon travelling to the village itself, he discovers a completely different reality to the one he had made up on the page.

Radio In The Footsteps of Alistair MacLean Radio Scotland, 11.30am Although kissed by money and fame after hitting his thriller stride, the fabled author was always troubled by the nature of literary success. The writer Philip Kerr pays tribute to the master who inspired him. And at 7pm in Performance on 3 (Radio 3) there is the first of four concerts from Glasgow's City Halls, with the BBC Scottish Symphony Orchestra performing works by Ligeti, Beethoven and Bartok, conducted by Ilan Volkov.