World Solve

Future progress on human development and planetary health depends on solving water reuse remaining rare. Conventional approaches have proven insufficient. The required intervention must integrate community knowledge, data and appropriate technology while remaining affordable, privacy-preserving and operable with minimal external support. Strong solutions will articulate measurable impact metrics, risk mitigation strategies, and a plan for sustained operation by local actors after the pilot phase.

Healthcare equipment often uses sterile, complex, or regulated components that are difficult to reuse. Future systems need to reduce waste while preserving infection control and clinical reliability. Affected communities must have meaningful control over data, revenue, deployment decisions, and the right to refuse harmful applications. The research opportunity is to define measurable success criteria, test the approach in realistic settings, identify failure modes, and create a pathway from prototype to accountable deployment.

The problem of design for reuse remaining rare continues to affect hundreds of millions of people and undermines progress on multiple Sustainable Development Goals. Existing responses remain fragmented, under-resourced and poorly adapted to local contexts. A strong solution must operate effectively under severe constraints of skilled personnel, infrastructure, electricity and connectivity. It should define clear measurable outcomes, identify possible unintended harms, and demonstrate how the intervention can be sustained by local institutions long after initial funding ends.

Large quantum computers may require specialized materials, cooling systems, and high-energy facilities. Their lifecycle impact, component reuse, and end-of-life management are not yet adequately designed. The solution must work with limited capital, intermittent services, and local maintenance capacity. The research opportunity is to define measurable success criteria, test the approach in realistic settings, identify failure modes, and create a pathway from prototype to accountable deployment.

The technical problem is coupled with a social allocation problem: production varies, meters may be imperfect, and residents need rules they trust. Tariff design, optimization, and transparent settlement tools could make shared generation investable. The opportunity is intentionally human-scale: a cooperative, clinic, workshop, school, or municipal team could pilot it within one locality and measure outcomes before expanding. Mathematical modeling can help with forecast uncertainty, incentives, or resource constraints; entrepreneurship can turn a reliable workflow into a viable service.

Materials may be valuable but poorly documented, contaminated, or unavailable at the needed time. Standardized audits, uncertainty-aware marketplaces, and logistics coordination could make reuse competitive with disposal. The opportunity is intentionally human-scale: a cooperative, clinic, workshop, school, or municipal team could pilot it within one locality and measure outcomes before expanding. Mathematical modeling can help with measure uncertainty, incentives, or resource constraints; entrepreneurship can turn a reliable workflow into a viable service.

When one website's user database is breached, attackers often successfully reuse those same stolen credentials on other unrelated websites where people reused the same password. Preventing this cascade of breaches remains an ongoing security challenge despite widespread password reuse warnings.

Datasets from many nations and disciplines remain siloed, hampering synthesis and reuse. Interoperable data platforms and FAIR-data policies can improve integration.

Mechanisms behind superconductivity in cuprates and iron-based materials remain contested. Combined experimental and theoretical work is needed to unlock room-temperature materials.

Toxic materials contaminate land and water. Stronger regulation and treatment facilities are needed.

Historic neighborhoods and monuments are frequently demolished to make way for commercial development, erasing cultural heritage. Digital heritage-mapping and adaptive-reuse financing models could balance preservation with growth.

Treated wastewater is rarely reused for non-potable purposes despite growing water stress in many urban areas. Decentralized greywater recycling systems for buildings could meaningfully cut freshwater demand.

In hot, dry climates, a significant portion of irrigation water is lost to evaporation before it ever reaches crop roots. Affordable ways to reduce this loss could ease water stress in agriculture-heavy dry regions.

Sustainable building materials often cost more or aren't as widely available as traditional concrete and steel, slowing their adoption across the construction industry. Making green materials the default rather than the premium choice remains unresolved.

The metals inside batteries and electronics are difficult and expensive to recover once a device is thrown away, so most end up in landfills instead of being reused. Cheaper recycling would ease both supply shortages and environmental damage.

Create safe, economically viable collection, sorting, repair, reuse, and material-recovery systems suited to decentralized local markets. The challenge is especially acute in informal settlements, where existing solutions often assume stable institutions, high incomes, continuous connectivity, or centralized service delivery.

Create shared infrastructure, sanitation, deposit, tracking, and business models that make reuse work across fragmented retailers and delivery systems.

Create decentralized treatment, safer chemistry, water reuse, and compliance models for dense clusters of small dyeing units.

Develop monitoring, crop-selection, treatment, and incentive systems that protect health while preserving a critical irrigation resource.

Develop surveillance and affordable safety protocols for dialysis delivered in fragmented private and informal systems, where contamination and equipment reuse may go undocumented.