The Grand Finale, Part One

Tens of light-years away, the cosmic storm, comparable to a supernova explosion, would take decades to affect the Solar System.

Yet Neptune's destruction had already dealt a serious blow to Earth.

Throughout April, earthquakes struck frequently all over the world, and many volcanoes awoke from dormancy. More seriously, even Earth's orbit began to shift, drawing it closer to the sun.

Scientists predicted that Earth's orbital radius around the sun would keep shrinking over the next few years, falling to 98% of its current length—or even less—before the orbit finally stabilized.

The most direct effect of a change in orbital radius was a change in Earth's temperature.

If the sun's radiant power was P and Earth's orbital radius was R, then T could be determined by equating the absorbed and emitted radiant energy: (1-r)R/(4πR^2)*πRE^2=4πRE^2εσT^4. A 2% reduction in the orbital radius would raise the temperature by 1%.

This temperature was not measured in the Celsius scale we commonly used, but in kelvins.

Take last summer's high of 53 degrees, for example. That was 326.15 kelvins. A 1% temperature increase would amount to a rise of 3.2615 degrees.

In fact, the impact of high temperatures on humanity was secondary. No matter how hot the weather got, people could always take refuge under air conditioning.

The problem lay in the chain reaction caused by rising temperatures.

Sea levels would rise rapidly, climates around the world would change drastically, and floods, droughts, hurricanes... all kinds of disasters would follow one after another. Most coastal cities and countries were expected to be swallowed by the sea.

In Earth's long history of evolving life, there was no doubt that this marked the beginning of a mass extinction event.

As a result, from May onward, humanity's migration efforts began to accelerate sharply.

The great human migration had