Green Party activist Zack Polanski says the climate crisis is the biggest threat to Britain since World War Two, arguing the country must respond urgently as recent heatwaves highlight the risk. In coverage of Polanski’s comments, he describes himself as an “eco-populist” and frames his role as sounding an alarm, directing demands toward the Prime Minister for faster or stronger action.

The reports also describe Polanski appearing alongside BBC presenter Chris Packham. In this context, Packham is portrayed as arguing that climate denial should be treated as a crime. The accounts link Polanski’s message about urgency with broader public debate over climate policy and attitudes toward denial.

Overall, the sources focus on Polanski’s assessment of the climate crisis and his call for government action, citing heatwaves as immediate evidence of the problem. They also reference a public event or media appearance involving Packham, including statements attributed to him on how climate denial should be handled.