The Late Ocean Age

270 Million Years PE

The ocean age has now provided stability to an unstable world for more than five million years, and since many animals had already begun adapting to living in the cool and plankton-rich mid-Ultimocene oceans millions of years earlier still, this additional time has now allowed for the evolution of several highly-specialized species, including new giants. At sea the productive vegetated shallows now constitute most of the sea floor, allowing the herbivores their time to grow larger even as the filter-feeding giants of the open sea have since died out.

The end of the ocean age would be near no matter what now, and its own success is to blame. The fully vegetated ocean forms a massive carbon sink that is slowly worsening the process of global cooling by pulling all carbon dioxide from the atmosphere and depositing it in deep ocean sediments so that ever more water is slowly frozen in growing ice caps. On the land, ever-creeping glaciation now claims almost all of the northern continent. Beyond the equator the summers are now fleeting and short, and the snow pack no longer thaws to reveal the soil below. Remaining hardy lifeforms have fled the inhospitable wastes of the north in a prolonged southerly migration and come to the final land-based refugia they can reach on the continent at the far southern steppe region, where meadows and bogs full of hardy puffgrasses lie in the damp, low-lying spots between sprawling thickets of cactaiga on the uplands. Here they find others who claimed these lands millions of years before. Competition for survival is fierce, and those forged from the harsh north often have the advantage.

The more water that freezes and is removed from the water cycle, the shallower the ocean becomes. The sea level is now so low that many islands have risen from it that now disrupt the flow of the equatorial current through the Icebox Seaway, the route that has maintained the open water here for long. Without this turbulence, the seaway would soon freeze and with it the rest of the ocean. This will be the fate of the world eventually, but it will not be how the ocean age ends.

A sudden and dramatic climatic shift is now not far off, and will upset everything in an unprecedented way. The ocean age has so far been a time of relative stability and security, and has provided a refuge for all walks of life during a mass extinction as the land was locked under glaciation, but all is soon to change. A spiraling chain of events soon to come will lead, one after another, to a culmination of the end of the current ice age - and with it this special sea ecosystem that so many rely on. Serina will be saved from its descent into an final icy grave for a while longer, but the specific circumstances that have made the ocean age possible simply could not be maintained in either possible future from this point on. Caught between a rock and a hard place, a temporary circumstance now nears the end of its lifespan.

The sequence of events that will ultimately lead to the end of the Mid-Ultimocene ice age, and with it wrap up the ocean age and lead to the end of the longest-lasting civilization upon Serina, fast approaches. It will begin with the actions of a single individual, and the repercussions of their actions will be felt around the world and for millions of years to come.