Investing in PERs (Plan d'Épargne Retraite) or life insurance involves decisions that are more nuanced than simple comparisons suggest. Every euro invested in these vehicles is directed into various sectors such as companies, bonds, and infrastructure, with real implications for the economy, climate, and future generations. However, most savers are largely unaware of the specifics of what their contracts fund. At a time when the **Paris Agreement** necessitates a transformation of economic models, private savings represent an underutilized lever for mobilizing capital needed for the energy transition. Choosing investment vehicles aligned with climate goals should be a standard practice, not exclusive to a minority of conscious investors. A significant concern is the issue of fees, which are certain in reducing capital over time. A 1% annual fee difference over twenty to thirty years can result in tens of thousands of euros less capital. These fees accumulate at multiple levels, including contract management, unit account, and entry fees, making comparisons complex for the average saver. Demanding transparency and favoring contracts with the lowest fees is a priority, comparable in importance to choosing between a PER or life insurance. PERs allow for deductions from taxable income, with savings typically blocked until retirement. In contrast, life insurance offers more flexibility, with reduced taxation on gains after eight years of holding. Both allow for favorable tax conditions when transmitting capital. The common-sense approach is to use PERs for retirement planning and life insurance for more flexible savings. The two do not exclude each other but complement each other. The real challenge is understanding the investment logic, real costs, and what these products finance, ensuring informed decisions without conflicts of interest.