The Effect of Climate Change on the International
System
Territorial integrity is an essential element of sov-
ereignty, but impedes migration. A vital question cli-
mate change poses is whether ecomigration requires
that this element of sovereignty be re-conceptualized.
The Modern State System: Sovereignty in the
21 st Century
In this section we will review the concept of sover-
eignty and begin to explore what climate change may
mean for the state system.
Few terms in international law are more difficult to
define than “state” and “sovereignty.” In May 2009,
the United Nations High Commissioner for Refugees
stated:
[T]here is no internationally agreed definition of what
constitutes a state, [but] there is agreement...that there
must be territory inhabited by a permanent population
under the control of an effective government (United
Nations High Commissioner for Refugees 2009a).Sovereignty and the state are essentially one: a
state is a polity established to exercise sovereign au-
thority. Customarily and by treaty (Convention on
the Rights and Duties of States 1933), a state must
have defined borders, and within those borders a state
possesses supreme authority and a monopoly on the
use of force. In short, a state’s borders are inviolable.
International law, domestic law, and state practice
all reflect this fundamental premise. A state, subject
to few exceptions, decides who gets in, and may use
force to maintain its integrity, character, and indepen-