On Jan. 8, the long struggle to maintain the habitability of south Louisiana for future generations will enter its most perilous period.

That’s when Jeff Landry becomes governor. And for the next four to eight years, the fate of the $50 billion plan for coastal survival will be at the mercy of a man who has spent his career denying the science and facts that plan is based on, as well as filing lawsuits to block regulations essential to its success.

Landry’s arrival could not come at a worse time. It presents residents south of Baton Rouge with the mother of all Category 5 hurricanes for their hopes.

Even before Landry’s election, we knew the next eight years would likely be a turning point for what the master plan could accomplish due to two converging existential challenges: Climate change and funding.

In 2007, the initial coastal master plan projected that, in 50 years, it could reverse the total land loss due to the subsidence that started when river levees blocked new loads of sediment on the delta landscape and the destruction and removal of wetlands by the oil and gas industry.

But in 2017, the Coastal Protection and Restoration Authority pulled that promise with this jolting news: The best the state can do now is limit the losses by 2070 to between 1,000 and 2,800 square miles — and more losses would follow after that.

The reason: Greenhouse gas emissions primarily from the use of oil, gas and coal continue to warm the atmosphere, causing record sea level rise.

The science shows that the “best case” loss of 1,100 square miles can only be accomplished if the world reduces emissions 50% from 2010 levels in the next seven years. And that can only be done by dramatically reducing the use of oil and gas.

But even if that is somehow achieved, the plan could still fall short because it is running out of money.

The plan needs about $1 billion a year to stay on schedule constructing levees and floodgates and rebuilding wetlands. It’s been able to keep that pace over the last 10 years thanks to funding from the Deepwater Horizon settlement.

But that money will run out in 9 years, and the state has still not found a new, permanent funding source. As projects come off the board, the Gulf of Mexico, rising at record rates due to emissions from oil and gas use, will force communities and industries to relocate.

The bottom line: To keep most of Louisiana below Interstate 10 above water through the next 50 years, the state needs to both find funding and help the world reduce emissions. Having one without the other will not help us stay here.

This was well-known before election day.

So, who does Louisiana choose to steer the ship of state during the crises? Landry, a man who denies the science and the facts on the ground over the last 10 years. Those facts include record ocean temperatures causing larger hurricanes, with higher storm surges reaching further inland and winds ripping off roofs and leaving communities without power for weeks in record heat waves.

All of which is causing insurance companies to leave the state, and those that stay to charge record premiums requiring special expensive riders for wind damage — and that only for “named” storms.

At Landry’s victory party, U.S. Rep. Steve Scalise, R-Metairie, another opponent of climate regulations, told an interviewer that one of Landry’s most important jobs was to slow the rising exodus of young, educated people from the state.

But those with college degrees will know Landry’s record on environmental protection and climate change. They will know the policies of the oil-loving governor will block any chance for slowing the growth of hurricanes and the rising of the Gulf over the next 20 to 50 years.

And when they get the insurance estimates for their first homes, they will quickly change any thought of having a future here.

In democracies elections have consequences. This one could be devastating for Louisiana.

Bob Marshall, a Pulitzer Prize-winning Louisiana environmental journalist, can be reached at bmarshallenviro@gmail.com.