In his book, The Coming Anarchy, Robert Kaplan wrote in 1994 that the wars of the future ‘will be those of communal survival, aggravated or, in many cases, caused by environmental scarcity’. He argues that in these wars, states will struggle to protect their own nationals adding the chilling conclusion, that ‘this is how many states will ultimately die’. Nearly three decades on, it seems that this dire prediction may be coming true. As conflicts around the world increase, migration ramps up pace, and nations are extinguished, we may be entering a Hobbesian world where natural disasters, rising sea-levels and resource scarcity lead to war and chaos.

Link between climate change and conflict

Many scholars have argued that climate change will directly cause more conflicts due to resource scarcity. States, they say, will enter into conflict over resource-abundant territory or for the resources themselves and stable governments will deteriorate. Pakistan may indeed be patient zero for such a phenomenon. After India suspended the water-division treaty between the two countries and has threatened to cut off the water to its lower riparian, Pakistan has responded that any attempts to do so would be considered an ‘act of war’. As Pakistan is heavily reliant on the Indus, any such measure by India would be an existential threat. Kofi Annan, UN Secretary-General at the time, stated as early as 2001 that “fierce competition for fresh water may well become a source of conflict and wars in the future.”

Others argue that there is no direct link between climate change and armed conflict and that any data supporting such an assertion is sparse and anecdotal. This is especially since the severity and frequency of armed conflict has actually decreased in recent years. Instead, they argue that climate change functions as a ‘threat multiplier’ which loads the dice in making conflict more likely. Therefore, the effects of climate change, such as food insecurity and natural disasters will lead to forced migration, economic decline, and increased competition, which may make conflict more likely. Conflict will therefore be one of the ‘consequences of the consequences’ of climate change.

Regardless of which approach is adopted, it seems climate wars are already here. UN Secretary-General at the time, Ban Ki-Moon, said in 2007 that the conflict in Darfur in Sudan was the world’s first ever climate change conflict as it was assumed that altered rainfall patterns caused the conflict. Since then, the Syrian civil war has also been attributed in part to a four-year long drought and the internal conflict in Yemen has also been linked to rainfall shortages caused by climate change. Even more concerning is the situation between India and Pakistan, where conflict over a scarce resource, water, could trigger an armed conflict.

The legal framework governing climate wars

The legal framework governing climate wars includes the prohibition on the use of force in Article 2(4) of the United Nations Charter under which there are two exceptions; self-defence in response to an armed attack in Article 51 and collective security operations under the Security Council in Chapter VII when there is a threat to international peace and security. For climate wars to be governed by the use of force framework therefore it would either have to constitute a use of force, an armed attack or a threat to international peace and security.

If India were to shut off the water to Pakistan, it would not currently engage any of these provisions. This is despite David Lilienthal, a water expert sent to Pakistan in 1951, stating that ‘no army, with bombs and shellfire, could devastate a land as thoroughly as Pakistan could be devastated by the simple expedient of India’s permanently shutting off the sources of water that keep the fields and people of Pakistan alive’. Legal academic, Craig Martin, argues for expanding the doctrine of self-defence in the case of atmospheric intervention. While not strictly applicable to the India-Pakistan example, he argues that states may decide to relax the conditions for self-defence to justify the use of force against climate rogue states (which make excessive contributions to climate change) or they may create a new exception termed ‘atmospheric interventions’. Martins notes that “If changes to the jus ad bellum regime could help with changing state behavior on climate change, then it might thus be justified, even if they increase the risk of war.”

Additionally, the Security Council could declare climate change a threat to international peace and security and demand collective action under Chapter VII of the Charter against climate rogue states who flagrantly violate their climate change obligations. This may be unlikely given the veto by the permanent five members, additionally, it may be unpopular among other states who would resent subjecting the internal affairs of states on climate issues to international scrutiny.

Issue of securitising climate change

While low-lying island states would prefer Security Council intervention due to their vulnerability in light of climate change, other states worry that the securitisation of climate change may result in the use of force against weaker States in the Global South. Moreover, this securitisation may get in the way of the cooperation required to deal with the effects of climate change. On the other hand, it may also ‘finally comprehend [climate change] as the biggest threat modern humans have ever faced’. Martin argues that because climate change is a global threat, it requires a ‘global security’ response under which the Security Council would coordinate and mobilise state action making it an urgent priority. He states that ‘Climate change should be framed as a security issue because we urgently need to respond to the threats to humanity’s most fundamental values…to reduce as best we can the grave risk of harm to human civilization’.

Future climate wars

The amount of carbon dioxide in our atmosphere currently is the same as that three and a half million years ago. If states do not take radical action, we are likely to exceed a 2 degrees celsius temperature increase by the end of the century, with its attendant threats to our ability to continue as a civilisation. In June 2025, the International Court of Justice delivered its landmark Advisory Opinion on states’ obligations with respect to climate change. The opinion confirms that international law requires states to prevent significant harm to the climate. Moreover, the ICJ held that the 1.5 degrees celsius temperature target is legally binding under the Paris Agreement and all states, especially the biggest emitters, must take ambitious mitigation measures. However, with states dragging their feet in complying with their obligations and resource scarcity making conflict between them all the more likely, it may be that an apocalyptic ‘climate 9/11’ event could serve as the catalyst which breaks states’ inertia.

This article by Ayesha Malik was produced with the support of the International Committee of the Red Cross (ICRC) as part of the Legally Speaking podcast series. The views expressed are the author’s own.