In the coming years, the European Union will face a dual challenge: a reduction in its energy supply and an increase in climate-related crises, often referred to as the "double carbon constraint." This concept, inspired by the 1972 The Limits to Growth report by the Meadows group, suggests that the EU must rethink its energy and economic models based on physical realities rather than abstract assumptions. The question is whether the EU can adapt or if it will be overwhelmed by these converging pressures. March 2026 marked a turning point: the Strait of Hormuz closed after the United States triggered war with Iran, oil prices surged past $100 per barrel, and European gas prices doubled within days. Around the same time, the continent faced severe heatwaves. These events—energy scarcity and climate disruption—highlight the "double carbon constraint," a term coined by the think tank The Shift Project. It refers to the simultaneous pressure of declining fossil fuel supplies and worsening climate impacts, both of which are likely to intensify in the coming years. The first challenge is familiar: reducing greenhouse gas emissions to limit climate change. This is a political and economic decision, though difficult to implement. The second challenge is less well known: the global supply of oil and gas is becoming increasingly scarce, regardless of policy. Experts suggest that global conventional oil production peaked in 2008, and gas production is expected to peak around 2025. These limits are already causing geopolitical tensions and extreme price fluctuations, which are not always tied to actual resource availability. A critical question remains: how to maintain economic growth while reducing reliance on fossil fuels. The transition to renewable energy, such as wind and nuclear power, depends on infrastructure that itself requires significant energy and resources to build and maintain. This creates a paradox: the low-carbon transition relies on the very systems it aims to replace. The European Union is particularly vulnerable in this situation. It imports 90 to 95% of its oil and gas, with an overall energy dependence rate of 58.4% in 2023. Only a few countries, like the Netherlands, Denmark, and Romania, have significant domestic production, which is also declining. While Europe often claims to have "decoupled" economic growth from energy use, this is largely due to moving energy-intensive industries to countries like China, not because of reduced overall energy demand. Globally, energy use remains closely tied to economic growth. Energy demand is set to rise sharply. The United Nations Environment Programme predicts that global energy use for cooling and refrigeration alone will increase from 5,000 TWh in 2022 to 18,000 TWh by 2050. This increase will require producing nearly half of the world's current electricity consumption just to meet cooling needs. Such challenges highlight the need for a new approach to energy use. Europe has an opportunity to lead by embracing a model of energy sobriety—careful and deliberate use of resources. Unlike the United States, which was built on the idea of infinite space and resources, Europe has historically lacked such illusions of abundance. This mindset allows the EU to prioritize energy use and set global standards before others do. The EU's ability to influence global norms, known as the "Brussels effect," gives it a strategic advantage in shaping the future of energy policy. However, the EU still faces challenges in implementing a comprehensive strategy. Current policies often treat energy, agriculture, transport, and industry as separate issues, despite the need for a unified approach. Moreover, economic indicators like GDP do not reflect resource depletion or vulnerability to shocks, making it difficult to measure progress in a way that reflects true sustainability. For energy sobriety to be accepted as a positive choice rather than a burden, the narrative must shift from one of loss to one of opportunity—rethinking lifestyle and quality of life beyond energy consumption.