The Acid Rain War was a major conflict of the Krark species on their homeplanet Kyrill. It was ostensibly focused on ending the use of fossil fuels and the acidic rains it had caused. The shifts in the balance of power caused as a consequence of the war would have far reaching consequences for the developement of the Krark as species and eventually promote the rise of the Stellar Empire.
After the developement of combustion engines and the industrial boom accompanied by it on large parts of Kyrill, fears over the environmental impact of athmospheric pollution reached new heights. While critical voices had already spoken out in previous decades, which saw an increased use of fossil fuels in the form of coal, it was this renewed phase of industrial expansion that saw the appearance of acidic rain as common occurence.
Acid rain was soon realized as existential danger by powers on the planetfacing side of the moon Kyrill, as its complex biosphere was dependant upon Kimoliafloiosids - large, tree-like plants covered in a thick shell of chalk - to protect it from the radioactive bombardement of its planet. This realization led to several ill-fated attempts at diplomatic solutions to the problem of global athmospheric pollution.
A majority of powers on the back of Kyrill, less affected by the consequences of widespread deforestation, had undermined or outright opposed attempts at binding pollution controls, as industrial growth had brought them an unprecedented era of growing wealth and influence. Deeming the issue an existential one, a coalition of planetfacing powers eventually declared their intention to use military force to stop the use of fossil fuels.