Scale 1 · Planetary
The Pacific moves as one system
Near-permanent trade winds heap sun-warmed water against Asia — a warm pool 8 °C hotter and half a metre higher than the east.
In a neutral year the winds hold that mountain of warm water pinned in the west. This is the resting state — one connected system, and the baseline every added pressure is measured against.
Scale 1 · The added pressure
In 2026, the signal strengthens
Slacken the trades and the warm pool collapses back downhill, rolling east as a Kelvin wave — a moving wall of energy.
This is the 2026 event, now unfolding: Niño-3.4 at +1.7 °C and climbing. One signal has shifted, and it is about to press on every system below. Follow it down.
Scale 2 · Oceanographic
The engine that feeds the sea stalls
In the east, cold water normally rises to within 30 m of the surface — the upwelling that feeds everything.
As warm water arrives from the west it forces the eastern thermocline down, to 150 or 200 m. The cold, nutrient-rich water can no longer break through, and the upwelling stops. The pressure now has a route upward.
Scale 3 · Ecological
The pressure climbs the food web
The tuna are not chasing temperature. They are chasing food.
Less upwelling means fewer nutrients, less phytoplankton, less zooplankton, fewer baitfish. The strain passes up every link — and the predators go where the food has gone.
Tuna follow the food, and the food follows the cold water.
Scale 4 · Fishery
The resource the region lives on is moving
A warming Pacific doesn't erase the fishery. It relocates it across national borders.
The glowing band is the tuna habitat centre; each dot is an EEZ over its real islands, sized by biomass share. The shared resource drifts from the western PNA waters toward the east — the same fish, now under different flags.
Scale 4 · Where it lands
The pressure lands unevenly
Movement alone isn't the story. The burden is.
Weigh each nation's dependence on tuna fees against how much of its own catch is slipping away, and the pressure concentrates. Micronesia sits near the top — heavily fee-dependent and watching its share decline — beside the small western nations whose fisheries fall fastest. The burden tracks need, not size.
If it strengthens · Super El Niño
A stronger event concentrates it further
In June 2026 the index was +1.7 °C and rising, with a real chance of crossing the +2 °C super line.
Push the scenario past +2 and the burden doesn't spread — it deepens on the same exposed nations. The bars stretch: same physics, more pressure, aimed at the least able to absorb it.
Scale 5 · Community
The national budget under strain
For several nations, tuna access fees are a majority of all government revenue. When the fish move, the budget moves with them.
This is who the pressure finally reaches: nations where three-quarters of the budget rides on a resource now drifting away. It is not a contest — it is a shared climate pressure, felt hardest by the communities whose whole economy is the fish.
Cross-section along the equator, Asia (west) to the Americas (east). The thermocline divides the warm surface from the cold, nutrient-rich deep that feeds the food web.
Each link's productivity relative to a normal year. As the base thins, the pressure travels up the chain — and the tuna follow the food.
Exposure — each nation's revenue dependence on tuna fees multiplied by how much of its own catch it loses versus a neutral year. Longer bar, heavier burden.
The message
One warming signal, felt across the whole Pacific — and heaviest on the island nations whose budgets ride on tuna that is drifting out of their waters. Seeing it early is how the region prepares.
See it for any scenario
The drivers, the forecast, and what it means to act early
The briefing above walked the scenario for you. From here the control at the top is yours — move it and watch the climate drivers, the forecast horizon and the live decision panel respond, so you can read the pressure under any ocean state.
The engine room · climate drivers
No single dial — a set of meshed gears
A forecast is never one indicator.
El Niño meshes with the Southern Oscillation, the Indian Ocean Dipole, the Southern Annular Mode, ocean heat content and the trade winds — each turning the others. Move the control and the whole assembly spins faster; that coupling is why the Pacific reorganises as a system, not a single variable.
Why forecasting matters · risk, not prophecy
The strongest tool we have is that we can see it coming
Niño-3.4 to mid-2026, then the forecast envelope. Confidence is tight near today and widens into the future — forecasting is risk management, not prediction.
In April 2026 three cyclones straddled the equator and briefly reversed the trade winds — the trigger.
By June the index reached +1.7 °C and kept climbing, with a majority chance of crossing the +2 °C super line. The Pacific Community's buoys, satellites and data pipelines exist so the warning arrives while there is still time to act.
Decision support · the questions that matter
What this scenario means, right now
Live answers for the scenario set on the control above.