Kharon. The Journey of Kyle Gibbs, #3

Book 3 in the Kyle Gibbs series. The year is 2033. A ship docks in Scotland's Glasgow Harbour. Men in hazmat suits stand guard as hundreds of figures dressed in rags trudge off the ship and are forced into trucks destined for the European continent. Following the three-metre sea level rise, the world is a changed place. Flooded megacities run by Warlords help the New Governments of America, Europe and Asia to keep control of the poverty-stricken masses.
This dystopian existence is now vulnerable to a deadly contagion threatening every Floodlander living in the megacities. A virus that will kill millions and topple the fragile New Governments from power. Desperate leaders are forced to recruit someone who can hunt down the brains behind the sinister organisation, hell-bent on holding the world to ransom. Ex-SAS soldier, Kyle Gibbs is living in a commune in the tranquil English countryside, oblivious to the fact that someone from his past is plotting to destroy his world.
Personal tragedy forces Gibbs to come out of retirement, and he is tasked with capturing the man who intends to cripple the world's governments. Will Gibbs do as ordered or seek personal revenge?