Greta Thunberg’s school strike against climate change has spread to 71 countries, and this Friday’s action could be one of the largest global climate change protests ever. Now nominated for the Nobel peace prize, she tells our environment editor Jonathan Watts how it all began. Plus: Gary Younge on how Brexit overwhelmed British politics

One day last summer, Greta Thunberg skipped school and went to sit outside the Swedish parliament with a homemade banner that read “skolstrejk för klimatet” (school strike for climate). One year on, her sign has been translated into dozens of languages and her school strike protest has spread to more than 70 countries. On Friday, tens of thousands of pupils will walk out of lessons and demand politicians urgently act on the issue.

In this episode, 16-year-old Greta tells the Guardian’s global environment editor, Jonathan Watts, how it all began and what she makes of the attention she has generated.

Also today: it’s been another manic week of Brexit bust-ups, but is the obsessive focus on amendments, process and meaningful votes crowding out major issues that people are really worried about? We hear from our columnist Gary Younge.