The Beginning of the Cosmic Era finds its roots in the middle of the current era, the petroleum era. No one currently calls our time the Petroleum Era, but no one called the Dark Ages by that name during the actual Dark Ages. In retrospect, the flaws of the era are plainly visible to the denizens of the Cosmic Era, and each is a condemnation against the regimes that dominate the globe.
The Sin of Industry - the Petroleum Era is driven by a highly materialistic first world, one that demands a constant flow of newness. New gadgets, new cars, new toys, new movies, new games, new new new more more more now now now. This facilitated the rise of the corporations into quasi-political and quasi-national entities, with margins bloated by borderline slave labor (an abomination that is blessed by the state religion of Globalism) the innately and horrifically wasteful planned obsolescence paradigm, and the high rate of resource exploitation around the world. Some countries made attempts at claiming high moral ground, and claiming themselves to be pro-environment, but this was just a matter of shifting their industrial carnage and waste to other countries and developing regions. The wages of the sin of industry are industrial cities left to rot and rust from the inside out as the corporations ever seek cheaper markets for their labors. It is open pit mines and strip mines that lead to erosion issues and acid rain. It is the litany of human rights violations that come when the deciding factor is factional pennies on the cost of a finished item.
The Sin of Garbage - The Petroleum Era with its planned obsolescence and it's disposable culture created the greatest piles of trash, greater than could feasibly be imagined. There was so much garbage produced that entire cities were devoted to nothing but sorting through the refuse, and the wealth from that refuse was enough to support an entire secondary economy. In the Cosmic Era, centuries after the end of oil, there remains an industry devoted to digging up the landfills and garbage heaps, tearing them apart and rendering new raw materials from the vast reserves of filth left behind. This garbage extends further than landfills and floating islands of trash, it includes the ruined cities, the derelict ruins of an age of decadence that choked on it's own feast.
The Sacrifice of the Environment - Though it would not reach it's peak until the Second Dark age when it was discovered the biosphere was so badly damaged that the environment was quickly going to be rendered unable to support large scale vertebrate life, much of the damage was done or set in motion during the Petroleum Era. The end of the Petrol Era sees widespread deforestation, massive loss of animal species, and the decimation of watersheds, and the fouling of the oceans. As mentioned above, some nations held themselves as if they were above the damage done, but while their forests were left standing, and they made gestures at conservation, their economic interests and activities ensured the rapid destruction of the environment around the world outside of their borders.
The Sin of Lucre - The ends justify the means, and to the victor go the spoils, and so the Petroleum Era went. There were only a handful of things that were important in the Petroleum Era, and they all boiled down to money. The environment was sacrificed for the bottom line. The world's resources were squandered for the sake of dividends. Entire moebian systems were built to ensure that the wealthy became more wealthy, regardless of the consequences. These included government systems that grew parasitically to ensure that the governments and corporations that funded them remained in place, unquestioned, unchallenged.
The Sin of Religion - Religious backed violence reached its crescendo during the end of the Petroleum Era, and was used as a major motivator and justification for the Resource Wars. While religion exists in the Cosmic Era, it is considered a far cry from the heavily armed, militarized, insurgency based faiths of the Petrol Era. Most hand the blame for this to Islam, as that religion generated the largest number of terrorists, but by the time of the Cosmic Era tempers have cooled and blame is also laid at the feet of Western Christianity for its increasingly violent tone, with economic demands pushing for cheap fuel (and by proxy, wars across muslim nations) and religious intolerance fueling those nations resolve to fight a religious insurgency with religious militarism.
Gaspunk is the predominant view of the Petroleum Era from the perspective of the Cosmic Era, and is as accurate a representation as Steampunk is of the Victorian Era. Gaspunk is all about hot-rods and suped up cars, jet skis, jet aircraft, motorcycles and the rest of the different sort of gas powered vehicles. Just as horses have to whinny and gallop anytime they are seen on television, so must automobiles do burnouts, belch fire from the exhaust pipes, and rev the engines with a mania only matched by teenage boys with a dirtbike. Guns, fisticuffs, and faked sexuality are also common tropes. The emphasis is on faked, as one of the tenets of gaspunk is embracing violence to almost sadistic extreme, while at the same time demonstrating an almost puritanical perspective on sexuality. Finally, gaspunk is authoritarian, xeno/poly/homo/technophobic, and wastefully decadent. A common theme translates out to starving to death inside a grocery store because one specific item was out.
Fashion cues are an amalgam of 70s bellbottoms and disco, 80s acidwash and grunge, 90s Traperkeeper post-modernism, and a chaotic mix of bits and pieces from as far back as the 50s. Thus it isn't uncommon to see things as strange as acid wash denim bellbottom jeans on a gaspunk hero while he flirts with a woman in a 60s hippie style peasant dress made of hypercolor fabric.
Anachronisms do abound in Gaspunk, though most are based around things that do exist in the Petrol era that most Cosmic Era denizens don't readily know about. The largest omission is that of the computer and the internet, with the typical view of the Petroleum Era being fixed somewhere around the mid 80s. Computers and such might exist, but they are so terrible that they aren't even worth mentioning. The era is typically seen as being entirely analog. Low energy weapons such as lasers are so common in the Cosmic Era that most Gaspunk set stories typically use lasers, even though such weapons are more than a century after the typical time period.
The Real Business
Everything above is largely fluff, and describes not so much the Petroleum Era, but perspectives on it.
Everything Goes Wrong - The failures of the Cosmic Era are things that I see going wrong now, and the Resource Wars are something that I think are going to happen. Hell, they might already be happening.
The Failure of Alternative Energy and Resource Management - The demise of the Petroleum Era comes from the inability and unwillingness of the powers that be to adopt non-fossil fuel based energy resources. In developing countries this can be dealt with because massive industries and infrastructures aren't hanging around as relics. Contrast this with developed nations that see things like oil, natural gas and coal based systems forced to run because the alternative is to retire those systems, consequently terminating the jobs, profit, and industries that exist to support them. The Petroleum Era says it has to use fossil fuels because that is what they are set up to run, and changing is just too expensive. Likewise, the planned obsolescence mentality shows no sign of going away. This is a tandem function of the demand for the next innovation, the next big thing with consumers demanding more crap and of the producers making sure that the last cutting edge thing they made starts to fail and fall apart in time to make sure the consumers aren't just rabid for the next wave, but with their gadgets wearing out, they have to be involved in it. Thusly, attempts to research and develop new energy resources aren't just underfunded, they are sabotaged.
The Paradigm of Control - While everything looks like it swirls around money and oil, the ultimate denominator is power. Not electricity, but control over economies, nations, and populations. This is the great commodity of the Petroleum Era, and it sees the emergence of the cyberstate, equipped with surveillance technology that would make George Orwell wet himself, and armed with computer tech able to sort through it. The Petroleum Era is doomed to its fate as the powers that be have made sure that regardless of what happens, they stay in control.
Big Brother - the computer surveillance state, algorithms exist that know the disposition of the population before the individual members of said population do.
Political Correctness/Crimethink - deliberate stupidity, the action of stopping a dangerous thought, one that potentially challenges or disagrees with the narrative paradigm. Freedom of speech exists, but only so long as it agrees with the paradigm, anything that goes against it is slapped with racism, terrorism, extremism, or some other label. You need not even do anything to be accused of these labels, as they may be arbitrarily applied to you at anytime for any reason. (10 ways you're unconsciously racist)Doublespeak - to answer a question without answering it, also to answer a question with bullet or talking points rather than engaging the actual query. (The War on Drugs, The War on Terror)
Fullwise - in 1984's rules of language, any word could be turned into an adverb by adding -wise to the end, thus removing other words from the lexicon. In the Petroleum Era, almost any word can become a verb or a noun through casual usage, replacing actual words with euphemisms, diluting the ability to express oneself. The primary implication is that unlike a proper noun or verb, a verbed noun or verb turned noun is limited in it's usage. The current stand out is the Facebook 'Like'.
The Emmanuel Goldstein - Corollary to political correctness and crimethink, the Emmanuel Goldstein is a figure who is held up by the narrative as someone to hurl scorn and invective upon for their actions, thoughts, or words. Thus, the public is guided in their outrage (he that angers you controls you) and at the same time cowed because it only takes a single viral exposure for anyone to become the next Emmanual Goldstein.
Newspeak - another term that is bandied about casually without being understood. The purpose of newspeak is dumb down communications, and to render large rational intelligent arguments down to the point that they cannot be held coherently. This is presently already happening in the form of memes, bumper sticker length thoughts, emoji, and the rest that renders communication down from debates and novels into tweets and captions on cat pictures.
Oldthink - the counterpoint of newspeak and political correctness, oldthink takes things in the past and makes them not just wrong, but immoral and evil, regardless or not of their actual status. If one does not conform to the newspeak and political correctness, they become guilty of oldthink and are vulnerable to becoming an Emmanuel Goldstein.
Proles and Prolefeed - You are a prole. Prolefeed is the litany of lowbrow, low quality, exploitative entertainment generated to keep the proles entertained. This is pornography, reality TV, talent competition shows, product placement shows, and the rest of the feed.
The Resistance - The enemy, the people who have to be fought because of their poisonous ideas, the nazis, the communists, the socials, the drug lords, the terrorists, the muslims. The people who must be feared, that the government protects the proles from so that the proles don't take down the government controlling them.
War by Proxy
Advances in military technology make war more profitable, and reduce the cost in human lives on the side of the technologically advanced aggressors. In previous decades, the impetus to go to war was tempered by the fact that it sent the sons, and then later the sons and daughters of the aggressor into harm's way. This often limited the ability of the various nations to engage in the profitable barbarism and resource denial campaigns they needed to. The solution came in the form of drones, autonymous fighting vehicles, and the precusors to combat robots like the skeletron. This allowed major wars to be waged with a minimum of life risked. Once war stopped being about lives lost, it suddenly became more attractive. It wasn't sons and daughters donning armor and picking up rifles, it was machines. Machines doing the fighting and the being destroyed, and that was boiled down to profit loss statements, and orders for more war machines.
War becomes the order of the day. So long as the homefront isn't hit (except every so often it is, to keep anger focused and patriotism high) the populations accept large amounts of war. It isn't their country being bombed, or their house being crushed under a drone tank. This mentality is retained well into the Resource Wars, echoing the pro-military, pro-violence culture that proliferated through Europe before World War 1. When the war later began in earnest, bombs fell, cities burned, habitats were shot out of orbit, chemical and biological weapons were slung across borders, and hydrogen warheads were detonated. This wasn't new, many of these things had already been done, but now everyone was involved, everyone was involved in the dying and the suffering.
But that is after the Petroluem Era ends.
The Hidden Knives
One of the relics of the Petroluem Era that persist into the Cosmic Era are the massively powerful and influential intelligence agencies that controlled the Petroluem era. Dozens of high power agencies existed during the Era, each involved in maintaining their power, their control over the various federal superstates, and basically functioning as the 'hidden masters' of the age. While many would style themselves as the Illuminati, their power was limited. As the Resource Wars would rage, their power would grow as they metastacized like a cancer, bloating themselves on the percieved need of their power. They people demanded safety and vengeance, and the agencies would comply. Many of these agencies would fall with the various superstates, while a few clung to power.
No agency would do so better than the Anunnaki. Not one single agency, the Anunnaki bloomed from a desperate merger of several failing agencies, all relics of the United States of America. By pooling their dwindling power and resources, they were able to facilitate the construction of the first generation arcologies, where they would make their stand, turning the structures into their own fortresses. They would remain in power, planting the seeds of what would become the mightly Atlantic Federation.