Welcome to this series of newsletters on the theme Net Zero by 2050: Technology for a Changing Climate. In response to the climate crisis, many business and industry leaders have committed their organizations to a ‘Net Zero’ program. By this they mean that their organization will not be emitting greenhouse gases by a specified date — often the year 2050. The purpose of these letters and posts is to help these leaders by providing realistic and practical information to do with net zero technologies. The emphasis is on the word ‘realistic’.