evidence: If the cement industry were a country, it would be the third largest emitter in the world - behind China and the US. It contributes more CO2 than aviation fuel (2.5%) and is not far behind the global agriculture business (12%). [...] The Intergovernmental Panel on Climate Change - the leading international body on global warming - last month argued the global average temperature rise needed to be kept below 1.5C - not 2C as noted in the Paris Agreement. This means CO2 emissions need to decline by 45% from 2010 levels by 2030. [...] But Mr Preston says it is imperative that governments and industry now act quickly at a time when global development is expected to rise but CO2 emissions need to fall.