Domestic sustainability policies constrained by or as a constraint for international investment law?

Under the pressures of environmental deterioration and climate change, States are implementing various policies in order to promote sustainability goals. This often implies restrictions on the scope of manoeuvring of private actors, sometimes resulting in losses of hoped for profits or outright economic damage. Over the last decades, international investment law has become a powerful tool in order to protect private investors against such moves on the part of their host states. This gives rise to the question whether the substantive guarantees and institutional arrangements of investment law are capable of accommodating for host states’ legitimate sustainability concerns or whether a normative reorientation must take place in order to safeguard states’ “right to regulate” in view of the momentous environmental challenges the globe is facing.