The Sustainable Schools Alliance has gone through a difficult period since its birth in 2011, with two of the three parent organisations more or less abandoning it. Fortunately, the remaining one, SEEd, has proved more tenacious, and a re-launch (you can take these birth metaphors too far) is in the offing.
As such, it is too soon to know how much of the original structures, vision, etc will remain. The mission of the original Alliance was ...
To drive change in the education system so that all schools put sustainability at the heart of their curriculum, their campus and their community. The Alliance will seek to achieve this by providing support and resources that help to link agendas around education for sustainable development, development education and health and well-being work in schools.
... and the vision was ...
Every child and young person experiences teaching and learning that enables them to feel safe and cared for in a changing world, where they want and are able to live sustainably and encourage others to do the same.
Although the original SSA website remains locked in a time when all three parents cooed (more or less) over their new arrival, the SEEd website provides more up to date information. This reminds us that the government endorsed the Alliance in the 2011 Natural Environment White Paper, although as something of an afterthought. Paragraph 4.19 says …
Through our delivery partner Keep Britain Tidy, we also support Eco-Schools in England. More than 16,000 schools take part in drawing up action plans on themes such as biodiversity, healthy living and managing waste and litter. Eco-Schools have been at the forefront of the Government’s programme to plant 1 million trees. We also endorse the new Sustainable Schools Alliance, led by the National Children’s Bureau and Sustainability and Environmental Education which was launched in March 2011 ... .
This was, of course, a Defra White Paper [Note 1], and there is no mention of the Department for Education within it [Note 2]. Thus, the attitude of Mr Gove to all this remains unclear, though some DfE civil servants remain, on the QT, very supportive.
Under a heading of Next Steps, the SEEd website says:
To put the management of the SSA onto a more sustainable footing a Management Board is currently being formed of 25 organisation who will support a part time SSA Officer, again supported by SEEd acting as the secretariat as it has been for the past 2 years.
Invitations have gone out, and that is where it is now are. More on all this, no doubt, especially when it becomes clear(er) what this Board, the officer, and SEEd, will be up to.
 Defra is a UK government department. Although it only works directly in England, it works closely with the devolved administrations in Wales, Scotland and Northern Ireland, and generally leads on negotiations in the EU and internationally.
 There is a footnote in the White Paper to a DfE publication: Department for Education (2010) The Importance of Teaching: The Schools White Paper. And, since you were wondering, there is no reference in this to environment, sustainability, the SSA, etc.