The DfE has launched its new environmental education strategy for consultation. Actually, they called it a (draft) Sustainability & Climate Change strategy (for the education & children’s services systems). You can read it here.
There are 5 mentions of curriculum, but none of them promise to reform / extend / change /develop / ... it. So, the Nick Gibb line that what the national curriculum says is adequate as it gives schools a direction and a sound base to build on, remains. Of course, it was never really Gibb's line, it was the DfE's; Gibb was only the reliably on-message mouthpiece. The prior emphasis on the curriculum being "knowledge-rich" also remains, as so it should. After all, who'd want what young people learn to be knowledge-poor?