Exhibition of the week Dear Earth: Art and Hope in a Time of Crisis Artists including Cristina Iglesias, Hito Steyerl, Cornelia Parker and Grounded Ecotherapy face up to the planet’s peril. Hayward Gallery, London, from 21 June to 3 September. Also showing The New National Portrait Gallery An ambitious reinvention of one of London’s familiar museums promises new ways of seeing portraiture and Britain. Reopens on 22 June. Life Is More Important Than Art Mitra Tabrizian, John Smith, Susan Hiller and more in a provocative, absorbing exploration of the real. Whitechapel Gallery, London, until 17 September. Moki Cherry Radical psychedelic tapestries with a countercultural jazz vibe. ICA, London, until 3 September. Katie Cuddon Clay may seem a predictable medium for sculpture but the fact that Cuddon works it with her teeth is less conventional. De La Warr Pavilion, Bexhill-on-Sea, until 3 September. Image of the week The Liverpool Biennial has opened in venues across the city, with many works exploring the legacies of the transatlantic slave trade. Among the works shown, our critic praised Binta Diaw’s at Tobacco Warehouse, which “uses soil to recreate the plan of the Brooks slave ship almost to scale. The plan was used by abolitionists to depict the horrors of slavery, and when enlarged to this size it is devastating.” Read the full review. What we learned The Moomins are taking their adventures to Paris India Mahdavi’s colourful Bonnard exhibition is dazzling Star architect Lina Ghotmeh’s Serpentine pavilion is less than stellar Photographer Evelyn Hofer was an underrated perfectionist Ayo Akingbade has captured the strange life of Lagos’s Guinness brewery Hamad Butt’s art diced with death Gego’s offbeat sculptures may be finding their place among the greats Gustav Klimt’s final portrait is expected to sell for £65m Banksy’s first solo show for 14 years will include the artist’s toilet Masterpiece of the week The Ambassadors by Hans Holbein the Younger, 1533 A mysterious atmosphere of melancholy hangs over this uncanny double portrait. The two men in it, French visitors to Henry VIII’s London named Jean de Dinteville and Georges de Selve, found time to pose for the king’s painter Holbein. But the artist lets his own obsession with mortality rip through the scene in the form of a vast optically distorted human skull. Its empty eye sockets mock the men and the objects of culture and curiosity that surround them: lute and globe, mathematical instruments and Turkish rug, all will be ruined by time. It’s clear from his other works that Holbein is infecting this uneasy picture with his own anxieties rather than just obeying the clients’ instructions. His dead Christ and series of prints The Dance of Death reveal a personal horror at life’s brevity. He worked in London simply as a mesmerising portraitist yet here his larger, darker vision melts reality with its despair. National Gallery, London. Don’t forget To follow us on Twitter: @GdnArtandDesign. Sign up to the Art Weekly newsletter If you don’t already receive our regular roundup of art and design news via email, please sign up here. Get in Touch If you have any questions or comments about any of our newsletters please email newsletters@theguardian.com