How big is your climate shadow? A concept is emerging to replace the carbon footprint – which critics say is at best time-consuming and at worst pointless. The enormity of the global climate crisis is so vast that individual steps may seem pointless: I can install LED lighting in my house or keep inflated tires they really help saving polar bears? One popular tool that helps individuals assess their contribution to climate change is carbon footprint calculatorThere are hundreds of such calculators available online, allowing you to input details such as the mode of transportation you use to commute to work, how often you eat red meat, and whether you wash your clothes in cold water. (KIERAN MULVANEY)