United States (Seyana)

The United States is a nation in North America. A former world superpower, the United States had maintained their power and influence in the world throughout the 21st and early to mid 22nd centuries. In 2153, the VEI-7 eruption at Valles Caldera took a major toll on the nation, with most of the states west of the Mississippi being buried by the volcanic ash. It led to the collapse of the country due to the disaster, a global economic downturn and subsequent civil disarray in the nation.

After an era of disarray, the United States later made a comeback in the 2230s, initially having all states east of the Mississippi, Minnesota, and the Dakotas as well as Bahamas and the Greater Antilles (sans Cuba).

Climate
Until the jet-stream shutdown in the 2050s, parts of the United States during the winter saw colder than usual temperatures, with snowfall occurring in places like Las Vegas and Phoenix on rare occasions, as the polar vortex dipped further south at times.

In the Southern and Eastern United States, flooding became much more common, especially as tropical storms and hurricanes increased in rainfall due to higher temperatures and increased evaporation. Although the amount of hurricanes per year continued to vary, storms in general increased in intensity leading to several hurricane seasons becoming on par or much worse than the 2005 season. The East Coast also saw an increase in hurricane landfall as conditions there becoming more favourable for hurricane activity. The 2039 Atlantic hurricane season saw the first category five hurricane making landfall in New York and New Jersey.

Meanwhile, the Tornado Alley had been shifting more eastward, with tornadoes increasing in the Southeast and other states on the East Coast. While tornado activity continued in the Great Plains, the frequency and intensity had declined, with record lows reaching a peak during parts of the early 22nd century.

In the Southwest the that occurred varied in strength and length each year with several factors such as the El Niño events in the Pacific.

Energy
Previously dominated by coal and petroleum, the United States made a long transition to renewable energy over the course of the 21st century; and by the early 22nd century had been dominated by renewables, with nuclear power being dominant (which produces 70% of energy demands), followed by geothermal and solar (primarily in the south-west and West Texas). Nuclear power itself is dominated by, with the first such plant being built in 2070, and makes up for 50% of nuclear energy, while fission plants make up the remaining portion.

had also been a major contribution for energy for a time during the 21st century and had displaced petroleum by the 2040s as the leading energy source. At its peak in 2055, its energy consumption was at 40%. However, shale gas met a slow decline in the 2060s following environmental concerns combined with a new nuclear renaissance. The last few shale gas plants still in operation were shut down in 2110.