The repetitive sound of conveyer belts and the hissing of insecticides linger long in the mind after viewing Nikolaus Geyrhalter’s Our Daily Bread (2005), both a savage and savagely beautiful documentary, focusing on European agriculture and industrial food farms. Geyrhalter’s kaleidoscopic style never passes judgment on his subjects. It juxtaposes the serenity of mass field harvesting at magic hour, with brutal hands-across-your-face moments. The methodical slaying of cattle in an abattoir via a centrifugal device, looks like something from 2001: A Space Odyssey (Kubrick, 1968), whilst the tagging, sorting and distribution of thousands of spritely chicks, ready for the battery farm, is unbearably cold and clinical—but bizarrely funny at the same time. Taken as a whole, this exceptional film is fervent about our dominant and sometimes indifferent position at the top of the food chain, making it leagues ahead of the atypical hunter/gatherer infodumps found on National Geographic.

On a different note, Al Gore presents us with An Inconvenient Truth (Guggenheim, 2006), making a pertinent argument on why global warming calls for change, asking us to take heed of a very real threat. Whatever your thoughts are on climate change, it is hard to deny Gore’s weighty arguments in verifying that this disastrous problem exists. His slide-show presentation intersperses powerful archive footage (some fetid home video from Hurricane Katrina, for example), interviews, flow charts, graphs and stills that make for a detailed polemic. Standout scenes include Gore talking about the horrifying possibility of “the Big Melt”, the collapse of major ice sheets across Greenland and Western Antarctica, which would raise sea levels to astronomical proportions. Detractors of the environmental movement should take note.

Even more disconcerting is Lucy Walker’s Countdown to Zero (2010), a hugely compelling argument on the threat of modern nuclear warfare, even as the Cold War has become a distant memory. Understandably, none of us wants to be on the brink again, but Walker’s film makes for a hair-prickling experience, particularly when revealing how an alarming number of warheads have gone unaccounted for. Countdown is chiefly propelled by interviews from key figures across the East and the West, including former General Secretary of the Communist Party of the Soviet Union (CPSU), Mikhail Gorbachev, and former Britain PM, Tony Blair. Their accounts of just how close worldly powers and terrorist factions have had their fingers on the button, while simulatenously keeping all of us in the dark, is potent food for thought.

Returning to Hurricane Katrina, When the Levees Broke: A Requiem in Four Acts (Lee, 2006) is about as epic and achingly profound as documentary filmmaking gets. Spike Lee’s dissection of this American tragedy hammers the Federal government for failing to respond and recognize those suffering during the aftermath of one of the U.S.’s most violent storms. It’s unimaginable that the richest, most powerful nation on the planet could react so poorly. As Lee’s film suggests, the refugees of New Orleans were not a priority, and ultimately Levees becomes a portrait of western humanity drowning in the floodwaters.