Grand Freeze

The Grand Freeze was a cataclysmic climate catastrophe which occurred in 6 AB, roughly six years after the United States 2020 Election. It involved the disappearance of the Atlantic Current which warmed much of North America and Europe, as well as a global ice age, as a direct result of uncontrolled atmospheric pollution and Combine technological radiation in Earth's atmosphere.

Buildup

For quadrillions of years, humans (and their ancestors) polluted the atmosphere of Earth with toxic and harmful substances. By 0 AB, the climate was beginning to change rapidly. Scientists across the planet attempted to warn the public of the impending catastrophe. However, thanks to the noble efforts of prolific climate change deniers such as The Great MAGA King and Chick Hicks, many people simply didn't believe it.

There was a small populous, however, that still believed in climate change, yet chose not to think about it. "Oh, nothing bad could ever happen like that. Not here!", they said, as their planet was ravaged by a deadly virus (as well as having freshly exited a multicentennial intergalactic war).

Foreseen Consequences

By 2 AB, many climate scientists began to see the writing on the wall. A third of an entire country was flooded by disastrous monsoon rains. Record heatwaves scorched Europe and Asia. A category 5 hurricane tore through the newly-formed North American Overlorddom's east coast, severely setting back civilian post-war recovery efforts.

Of course, the deniers continued to deny. "Weather's always crazy", they said, as walruses flopped down the sidewalks of Jacksonville Florida and thousands died in northern Europe from heat stroke.

That autumn, tropical storms ravaged coastal areas across the planet. This was nothing new, however, as the Downward Spiral had been propagating increased cyclone and typhoon production due to its physical instability. The United Nations (a soon-to-be-dissolved ineffective alliance of countries worldwide) declared the Earth was in a state of a 'Climate Emergency'. The North American Overlord would soon follow up with his own statement, citing the reason for the climate's increasing erratic behavior as being due to 'mung beans'.

It's important to highlight how many people knew the climate was changing; how many wanted to make a difference. Indeed, many people across the world worked to adopt more sustainable lifestyles.

Unfortunately for them, the capitalist machine marched forward into a thick black fog of oblivion. China's Global Pollution Initiative contributed to massive amounts of Carbon Dioxide being blasted into the atmosphere. James Fargo of J.F. Sweets worked tirelessly to spread misinformation about the climate, sharing such thoughts as 'windmills cause cancer' and 'solar powers are Combine tech'.

Climate Catastrophe

Four years later, in 6 AB, the Earth's climate had drastically changed. Rising sea levels and a changing atmospheric makeup had permanently altered the currents in the ocean, rendering Europe and North America icy wastelands. Around half of Earth's population (tens of billions) died from malnourishment from 3 AB-6 AB. Coastal cities were completely flooded, and most world governments fell into disarray. Many hogs still claimed that Climate Change was a hoax. "Winter always comes!", a tightly-bundled up Spanish man said to a reporter, while tending his potato plants during a fierce European blizzard in August.

Bailout

On April 5th, 7 AB, everyone woke up to find that the Earth had been returned to a stable atmospheric state (as it had existed ten years prior). This was thanks to the Anti-Climate Change Technology developed by J.F. Sweets. They didn't save the world out of the goodness of their hearts; they did it because it was profitable. This 'good deed' was hailed by Mummy as a "Grand Blessing", and J.F. Sweets were granted a 40% share in the North American Overlorddom (rendering the government an elitist oligarchy). J.F. Sweets would continue to brag about this deed for the rest of Omniversal History, dangling it over the heads of civilians who accused them of being a 'corrupt gigacorporation'.

It's worth noting that no such Bailout will happen in your Reality, should the Grand Freeze occur.