Woodworker Elvis Halilović, through his brand ONDU, recently unveiled a series of pinhole cameras made from wood, and is using the website Kickstarter to help boost production.

It’s a surprising figure, however cement production is reckoned to emit 5 to 6 percent of total man made greenhouse gases, Some of the greenhouse emissions from conventional cement production come from using fossil fuels to heat up limestone to the high 1500degC, temperatures required by the process, so it is unsurprising that alternative fuelling methods are now being thoroughly exploited. The use of alternative fuels in European cement kilns is now estimated to be equivalent to 2.5 million tonnes of coal per year.