Louisiana Has a Decade to Move on Its Coastal Master Plan | The Times-Picayune

Louisiana has a decade to move on its coastal master plan

Isle de Jean Charles (Photo by Ted Jackson, Nola.com | The Times-Picayune)

After covering (and living) Louisiana’s coastal crisis for decades, the most common question I get these days is this one: When will we know if state’s coastal master plan will succeed?

Well, a solid answer can finally be given: In 10 years.

That deadline is based on these two developing factors:

  • Last week the Intergovernmental Panel on Climate Change (IPCC) issued a new report stating that the world has just 10 years to cut greenhouse gas emissions by staggering 40 percent or the planet will be locked in to dramatic impacts from warming before the end of this century. That includes sea level rise high enough to swamp most of Louisiana below Interstate 10.
  • Louisiana has about 10 years to find a large, recurring funding source for its coastal plan, or it will have to begin dramatically reducing the number of projects or abandon the plan for other options, including retreat.

Let’s take those challenges one at a time.

In 2015 the world community concluded the Paris Climate Agreement to prevent the world’s average temperature from rising more than 1.5 degree Celsius (2.7 degrees Fahrenheit) by dramatically reducing emissions, the main driver of warming. Even at the time most climatologists agreed the pledges by the signatories would not hold temperatures below that 1.5-degree mark. And when President Donald Trump recklessly pulled the United States – the second-largest producer of emissions – out of the agreement, the outlook got even grimmer.

“The pledges countries made during the Paris climate accord don’t get us anywhere close to what we have to do,” Drew Shindell, a climate expert at Duke University and one of the authors of the Intergovernmental Panel on Climate Change report, told The Washington Post. “They haven’t really followed through with actions to reduce their emissions in any way commensurate with what they profess to be aiming for.”

The 10-year deadline is linked to carbon emissions. This long-lived pollutant stays in the atmosphere for years adding to warming long after it is released. Researchers believe if that 40 percent reduction isn’t reached in the next 10 years, a tipping point will be crossed after which certain warming impacts from the carbon buildup will continue for decades or centuries – even if emissions are reduced after that.

Louisiana’s coast also has already suffered the impacts.

The Coastal Protecti0n and Restoration Authority, which runs the coastal master plan, uses a straightforward analysis to decide just how much of the coast it can rebuild and strengthen. The key variables are how fast an area is sinking, how fast the sea is rising and how much sediment it has to work with.

When the plan was introduced in 2007 CPRA computers indicated if all the projects were built on time, we could be building more land than we’re losing in aggregate by 2067. The 2017 edition retracted that claim. The agency now says we are locked in to losing another 1,200 to 2,800 square miles of the land below I-10 by 2067.

The reason: sea level rise estimates have been steadily rising because emissions have not been slowing quickly enough. Indeed, the worst-case scenario for sea level rise in the 2012 edition of the plan is the best-case scenario in the current version.

So, our coastal future is now tied largely to how much, and how quickly, the nation and the world can reduce carbon emissions. And now the latest IPCC report is sending a clear message to Louisiana: If the problem isn’t solved in 10 years, we may have to start looking at other coastal options (See: Changing Course)

Which brings us to that second challenge: Funding for the master plan.

Read the rest of the article at The Times-Picayune.