A republic of insects and grasses

While insights into the nature of the world in the wake of warming by several degrees Celsius and a nuclear war cannot be reached in detail, a number of projections arise from paleoclimate science and from current observations and trends. The increased concentrations of CO₂ above 405 ppm and CO₂e (equivalent CO₂ including methane) are tracking toward the stability threshold level of the Greenland and West Antarctic ice sheets and sea levels many meters higher than at present. Given sea levels in the range of 25 ± 12 m during the Pliocene pre-2.6 million years ago, the world’s delta, low river valleys and coastal zones, the focus of much of human agriculture and civilization, will be flooded by sea water. As the Earth warms, the balance between increasing aridity in heated desert regions and enhanced hydrological cycle and precipitation in other regions would result in sharp climate gradients and intense storms. With a plutonium-239 half-life of approximately 20,000 years, the effects of radioactivity would decline. At this stage, large habitats vacated at the onset of the Plutocene due to climate tipping points and high radioactivity would be re-occupied by tropical flora and fauna, notably the Arthropods. Accelerated speciation is observed during rebounds from mass extinctions and pulses of speciation appear sometimes to be associated with climate change.