Foreign investors benefit from rights to the protection of their foreign
investments under a web of thousands of international investment agreements
(IIAs). Those IIAs traditionally, however, contain no corresponding duties. The
presence of rights without corresponding obligations in the global system of
investment protection has attracted significant criticism. This is particularly
true in the field of environmental protection (including the fight against
climate change), where the concern is that the promotion and protection of
investment may unduly restrict a State’s ability to take measures that promote
environmental objectives. This article analyses what IIAs do or could do to
contribute to the goal of environmental protection, in three parts: first, it
identifies provisions of ‘old generation’ IIAs (i.e., those concluded prior to
2010) that provide scope for environmental considerations to be taken into
account; second, it analyses the trend in recent IIAs and model Bilateral
Investment Treaties (BITs) to incorporate mechanisms aimed at promoting
environmental protection in relation to the regulation of foreign investment;
and third, it analyses various possibilities for reform of international
investment law to further promote the protection of the environment in the
field of foreign investment. It concludes that while the texts of the vast
majority of IIAs currently in force appear to do little directly to promote
environmental objectives, some contain certain mechanisms that are capable of
allowing tribunals to give environmental concerns the weight they deserve. In
relation to new and renegotiated IIAs, there are a wide variety of mechanisms
that can be used to enhance the contribution they make to promoting sustainable
investment and investment in green industries.