Since 2009 Thomson's speeches and media releases have often dealt with problems of Australian and global population growth. In August 2009, following a terrorist scare, Thomson attracted controversy with his comments regarding the link between high immigration and allegedly poor screening of immigrants for terrorism. Thomson repeated his call to cut immigration levels in September 2009 following the release of a report indicating that the population of Australia would grow to 35 million by 2049. Thomson said that Australia was "sleepwalking into an environmental disaster", and predicted that such a population would tend to outgrow its resources of "food, water, energy and land".