Return of the Ice

70,000 years hence, Earliest Recurocene

The end-Holocene Climatic Optimum may have brought a warm and varied world, perfect for life, but it was not to last. Earth is remarkably quick at adsorbing CO2, and it took only around 50,000 years for all of the excesses CO2 levels created by man to be absorbed by the oceans, forests and sediments. Back to natural levels, the ocean currents came back into play - with the Antarctic Circumpolar Current still going strong and the Isthmus of Panama remaining closed, the world would continue cooling. And before long, the interglacial period man had extended for so long with their carbon emissions came to an end, and gave way to the next glacial cycle. The Quaternary Ice Age had returned, and the Recurocene had begun.

With glaciation gripping not only the poles but also large areas of the Northern Hemisphere, vast quantities of water were locked up in ice once more, and shorelines around the globe quickly retreated. With the ocean receding to the edges of the continental shelf, all of the landmasses that make up the Australian continent became joined by land once more, and the true shape and size of the continent was revealed.

Unfortunately for the animals that had adapted to Australia's new habitat arrangement, this has changed radically once again. This cooling brings much drier conditions, and it wasn't long before the vast northern rainforests that had claimed northern Australia began to dry out and die. Species that called these forests home either followed it back to the coasts or died with it, as it vanished into an arid landscape of sand and spinifex. The continent's habitat arrangement was largely reverting to that of the Pleistocene, which displayed nearly identical glacial conditions. The majority of Australia is now once again covered in dry scrub, sandy plains and sparse arid woodlands. It seems that the desert has once again taken over the continent, adding both challenge and opportunity for organisms trying to make a living in the inland.

With land exposed, land-bound species could now travel between New Guinea, the 'mainland' and Tasmania once more, and interchange commenced. Across the wetlands of the previously submerged Arafura Floodplain, perhaps the most important migrants marched their way south - the cats, deer, pigs, buffalo and toads were making their return.

While one would assume that the return of these species would cause an ecological catastrophe, it is not so. Not only are these species more suited to the ecology of the Australian continent from their time spent in New Guinea, but invasive species tend to do their worst damage when there are many of them pressuring the same ecosystem at once. This is why the ancestors of the Dingo seem to have not caused many extinctions when they arrived - they were alone. While of course in this situation there are several species, including what was historically Australia's most destructive pest (the cat), without the added pressure of foxes, rabbits, goats and others, these species blended into the ecosystems in a few thousand years quite harmoniously, causing very few extinctions. Notably, the invasive herbivores were restricted to the narrow habitable strip along the coast - without humans providing permanent water sources, only the hardy cats and cane toads are able to survive in Australia's harsh arid interior.

With the factors that brought on this ice age showing no signs of going away, it is clear that the earth shall remain glacial for millions of years to come. Despite the challenges these conditions bring, with humans out of the picture and conditions now beginning to stabilise, a new chapter in the story of life was ready to begin.