World Solve

Right now we can only detect exoplanets indirectly, through shadows and wobbles in starlight. Direct imaging would let us actually study alien landscapes and atmospheres instead of just inferring their existence.

Arrow's Impossibility Theorem proved certain fairness conditions can't all hold at once for common voting systems, but the full landscape of tradeoffs across all possible systems remains an active research area. This has real implications for the design of democratic institutions.

Gödel's theorems already limit what's possible here for sufficiently powerful systems, but the full landscape of alternative systems and their limitations remains an active and unresolved area of mathematical logic. This continues to shape our understanding of the foundations of mathematics itself.

Parts of the Greenland ice sheet may have already crossed tipping points where melting continues regardless of future emissions cuts. Understanding and potentially slowing this process remains one of climate science's most urgent unresolved challenges.

Vast areas of farmland worldwide have been degraded by decades of intensive use, and restoring their fertility can take years even with the right techniques. Scaling this restoration affordably remains an unresolved agricultural challenge.

Wetlands absorb floodwater and protect surrounding areas, but they continue to be drained or developed faster than they're restored in many regions. Protecting or rebuilding this natural infrastructure remains an unresolved environmental priority.

Many cities lack convenient composting systems, so a significant share of food waste that could be composted still ends up in landfills producing methane. Scaling accessible composting infrastructure remains an unresolved urban sustainability challenge.

Overgrazing, deforestation, and changing rainfall patterns continue to push arid regions toward full desertification faster than restoration projects can reverse. Scaling effective land restoration to match the pace of degradation remains unresolved.

Tropical forests host a huge share of the world's biodiversity, and converting this land for farming, even when done for legitimate food needs, often results in permanent species loss. Balancing food production with biodiversity protection remains unresolved.

Construction and demolition debris makes up a significant share of total waste in many rapidly growing cities, and recycling this material at scale remains inconsistently practiced. Reducing this waste stream remains an unresolved urban sustainability issue.

As farmland expands to meet growing food demand, it frequently cuts through pathways that wildlife species depend on for seasonal migration. Balancing agricultural needs with preserving these corridors remains an unresolved land-use challenge.

Arctic wetlands store significant amounts of carbon that can be released as methane when they thaw, potentially creating a feedback loop that accelerates warming further. Preventing or slowing this release remains beyond current technological capability.

Aggressive logging can strip forest soil of the nutrients and structure it needs to regenerate tree cover, sometimes leading to long-term land degradation. Making logging practices consistently sustainable remains an unresolved global industry challenge.

River deltas provide fertile land for millions of people but are increasingly eroding due to upstream dam construction and rising sea levels reducing natural sediment replenishment. Protecting these critical, densely populated areas remains an unresolved challenge.

Degraded peatlands release significant amounts of stored carbon, and restoring them to their natural, carbon-storing state requires careful, sustained management that many restoration projects don't achieve. Making this restoration reliably effective remains unresolved.

Draining and clearing carbon-rich peat swamp forests for agriculture releases enormous amounts of stored carbon while also destroying unique ecosystems. Preventing this specific type of high-impact land conversion remains an unresolved policy and enforcement challenge.

A large share of organic waste still ends up in landfills producing methane simply because industrial composting infrastructure isn't available in enough regions. Building this capacity out at the scale needed remains an unresolved waste management challenge.

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.

Entire island nations and coastal communities face losing their homes permanently, with no agreed international process for where they go or who helps pay for it. This is already happening, not just a future risk.

Hotter, drier conditions combined with decades of fire suppression have left forests primed to burn catastrophically. Managing this risk needs new approaches to land management, not just faster firefighting.