First published in 1939, Steinbeck’s powerful tale of  greed, corruption and the consequences of intensive farming is a stark reminder that man-made environmental disasters are far from new. The story tells how the beleaguered Joad family, forced to join the great wave of migrants leaving the poverty of Oklahoma’s ruined Dust Bowl, travels in search of the green orchards of California, with its “golden oranges hanging from the trees”. But there’s trouble in paradise…