Alexandria Ocasio-Cortez has gone in to bat for Greta Thunberg after the teenage climate activist was talked down to by a member of the Trump Administration this week.

The congresswoman took to Twitter to show her support for Thuberg after US treasury secretary Steven Mnuchin suggested she should study economics in order to be taken seriously.

Mnuchin pretended not to know who Thunberg – the teenage environmental activist who is widely credited with inspiring the global youth movement against climate change – was, before dismissing her climate concerns as ill-informed.

Alexandria Ocasio-Cortez just offered Greta Thunberg some advice on “haters”