World Solve

Future progress on human development and planetary health depends on solving severe overcrowding in major cities. 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.

Cities may deploy scent systems that automatically adjust collective emotional states. Over time some residents develop tolerance or adverse reactions, creating uneven effects and new forms of environmental inequality. The problem is designing transparent, opt-outable, and medically safe atmospheric interventions that do not become tools of coercion or social control.

Urban growth, migration, and climate change will outpace traditional master planning. The challenge is designing governance that can revise land use, service delivery, and infrastructure priorities continuously without becoming arbitrary. This becomes particularly difficult in post-conflict institutions, because public institutions must remain fair, resilient, and accountable while adapting to new risks.

Future cities may experience extreme heat precisely when electricity and water systems are least able to support cooling. The challenge is coordinating urban design, demand management, public health, and energy policy under compound stress. 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.

Curb demand changes by hour and street, but regulations are often static and enforcement is inconsistent. Auctions, reservation systems, and fairness constraints could improve throughput while protecting accessibility and local commerce. 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 preserve uncertainty, incentives, or resource constraints; entrepreneurship can turn a reliable workflow into a viable service.

Current approaches to solutions for providing safe and accessible public transport in rapidly growing secondary cities either underperform under variable field conditions or generate externalities that undermine long-term sustainability and equity. Closing the gap requires coordinated advances in science, systems design and enabling institutions.

As cities adopt more connected infrastructure for traffic lights, utilities, and public services, the potential attack surface for disruptive cyberattacks grows correspondingly. Comprehensive security for these interconnected systems remains inconsistently implemented.

Wireless carriers often prioritize dense urban areas for network upgrades because they're more profitable to build out, leaving rural regions with slower, less reliable coverage. Closing this rural connectivity gap remains a persistent infrastructure challenge.

Mega-cities will produce unique mixtures of traffic accidents, air pollution, and sedentary lifestyles. Urban health observatories and built-environment intervention tools will be critical.

Lyme disease, dengue, and other infections may reach new regions. Integrated vector-surveillance and control platforms will be crucial.

Agriculture, hydropower, and urban water supplies are increasingly affected by changing rainfall and heat patterns. Climate-risk modelling and adaptation investment platforms can help prioritise responses.

Economic shocks and informality push more city dwellers into precarious living, adding pressure on housing and services. Slum-upgrading and urban social-safety-net platforms could mitigate these trends.

Pandemic-era debts and modest growth make it hard to fund security, social policy, and climate adaptation. Debt-transparency dashboards and innovative financing instruments can support better decisions.

Droughts and glacier retreat complicate water allocation for cities, farms, and energy. Basin-level data platforms and negotiated allocation tools can support sustainable management.

Droughts and glacier retreat complicate water allocation for cities, farms, and energy. Basin-level data platforms and negotiated allocation tools can support sustainable management.

Car-centric growth and limited mass transit investments cause gridlock and unhealthy air. Transit-planning tools and clean-mobility ventures can address these challenges.

Investment priorities focus on capitals while smaller cities struggle with outdated fleets. Regional funding and planning platforms can spread best practices.

Major urban centres like Berlin, Paris, and Barcelona face rent and home price surges that outpace incomes. Policy-simulation platforms and modular construction ventures could inform and implement solutions.

Young people leave for cities or abroad, leaving ageing communities and underused infrastructure. Remote-work incentives and smart-village platforms can help revitalise rural areas.

Extreme events cause health impacts and infrastructure damage, testing adaptation plans. Urban heat and flood-risk modelling tools plus nature-based solution marketplaces can support responses.