It is the age of the Anthropocene. With far-reaching changes to economy and technology, society and the environment, humanity has gained the capacity to either foster or foreclose the quality of life for future generations. Through degradation of the Earth’s marine and terrestrial ecosystems and its climate, including the natural resources upon which all people depend, human civilization holds the potential to deprive billions of their rights to life, taking millions of other species as well. Particularly as social, economic and environmental transformations and impacts of the recent global COVID-19 pandemic become more apparent, a growing recognition of the risks and threats is slowly changing perceptions of humankind’s responsibility for its descendants. Since the 1972 UN Conference in Stockholm, numerous international policy declarations have reflected increasing concern for the need to promote a more sustainable development that can take into account the needs and interests of future generations, including the global adoption of the 17 Sustainable Development Goals (SDGs) and their 169 targets in 2015 by Heads of State in New York.

International law reflects the values shared by States and has helped them face the most consequential challenges of the day. After the Second World War, the most significant challenge was to preserve international peace and security, as well as to guarantee basic human rights. In the twenty-first century, States face a new challenge: climate change and its consequences, and, ultimately, the survival of all mankind. Unfortunately, the consequences of climate change are highly visible – for example, extreme weather conditions (droughts, heatwaves and devastating storms, floods in areas where people have never experienced similar events before), melting ice in the Arctic, the extinction of some native plant and animal species and the appearance of unknown invasive species in the same area.

For humanity and the Earth, it is crucial that present institutions learn to respect and honour the rights of future generations and to consider the needs of those who are yet to come. The rights of future generations are starting to be recognised as an essential part of policy decisions and even as a legal requirement in an increasing number of countries. Indeed, some countries and communities have begun to design innovative instruments to represent the voices of future generations in their policy-making processes, and to better realise these rights. The need to respect and realise the rights of future generations has also been adopted by the international community through treaty law and through the jurisprudence of eminent courts and tribunals such as the ICJ. Indeed, the UNGA now considers the rights of future generations in its global deliberations, and several proposals have been generated among experts for the creation of new international instruments to represent the voices of future generations in global policy making. Perhaps the most concrete form of policy guidance, and arguably the most visible place, for future generations in the UN context is the 2015 SDGs. At this point in time, it is helpful to summarise and analyse the new domestic and international institutions that work to deliver on the rights of future generations. Indeed, surveying the more progressive national innovations and the principal international trends in this domain make new options possible for policy makers wishing to establish novel instruments to adequately protect the rights of future generations at national and international levels.

How are concepts related to intergenerational equity reflected in the European constitutional order? This chapter will offer answers to this challenging and constantly emerging question and shed light on the interrelationship between intergenerational solidarity and sustainable development within the European constitutional system.