According to Macmillan, this novel comes out in the summer of 2022:
Ruthanna Emrys crafts a novel of extraterrestrial diplomacy and urgent climate repair bursting with quiet, tenuous hope and an underlying warmth. A Half-Built Garden depicts a world worth building towards, a humanity worth saving from itself, and an alien community worth entering with open arms. It’s not the easiest future to build, but it’s one that just might be in reach.
More to come later!