Region’s leaders need better science to cope with sea-level rise

For example, sea-level rise is worsening tidal flooding. Miami and Miami Beach are collecting data they’ll use to build interactive tools to help property owners understand their risks.
For example, sea-level rise is worsening tidal flooding. Miami and Miami Beach are collecting data they’ll use to build interactive tools to help property owners understand their risks. Getty Images

As a climate scientist, I’ve been asked one question over and over: “What keeps you up at night?”

What kept me up 20 years ago isn’t the same as what did 10 or even five years ago. Now when asked, I share my concern that while we have a very good handle on “global” climate science, the science we are conducting should be done in a way that’s more helpful to decision-makers who have to implement solutions at the local and regional level.

With the Intergovernmental Panel on Climate Change (IPCC), we have a powerful mechanism whereby top scientists seek to objectively assess the state of the global climate system and our understanding of it. Some of the key conclusions of this United Nations agency’s fifth assessment report bear repeating:

Since the 1950s the climate system has unequivocally warmed. There is ample evidence -- many studies that involve different observational instruments that measure different components of the climate system -- that supports this conclusion. The bulk of the warming since the 1950s is extremely likely due to human activities such as increases in CO2 levels associated with the consumption of fossil fuels.

In Florida, sea level merits special attention. Sea-level data from the last 3,000 years has been remarkably stable – until about 1900. However, since then, sea level has steadily risen consistent with the warming that has been documented. There is evidence that at regional scales along the eastern U.S. and in Florida in particular, the sea-level rise is accelerating.

There’s no compelling scientific evidence that any of the trends we see will reverse themselves. In fact, the evidence is that current trends will continue for at least the next 25 years, perhaps well beyond.

There’s even evidence that some trends may accelerate. Even if one is skeptical that human activities are the cause of these trends, there is a clear local need to protect lives and property, and ensure economic opportunity.

However, to aggressively adapt, we must re-think how we do the basic science of prediction that underpins our adaptation decisions. That’s because adaption is a local and regional issue and the IPCC was not intended to provide scientific guidance at this scale.

For example, we lack good estimates for the expected changes in rainfall over the next 25 years for South Florida. Current estimates suggest either a 10 percent decrease or a 10 percent increase. The lack of detail makes it difficult to properly plan the restoration of the Everglades.

Are the chances of a 10 percent decrease the same as the 10 percent increase? When can we expect these changes? Are the changes only in the wet season? When will we cross critical thresholds?

The lack of specifics is because the IPCC climate simulations aren’t designed to provide information needed for local adaptation decisions. As a result, the people guiding the Everglades restoration are forced to do herculean scientific gymnastics to glean, at best, inadequate information.

Fortunately, the citizens of Miami approved a bond issue that includes roughly $200 million to cope with sea-level rise. The public and policy makers alike need to be confident that adaptation strategies are supported by the best possible science. Our policy makers need mechanisms that guarantee that the questions they are grappling with drive how the science is done.

At the moment, adaption strategies are, in part, based on climate simulations that do not take the specific adaptation needs into consideration. This disconnect between the science and the problems hampers the effectiveness of our adaption strategies.

Scientifically based predictions of the next 25 years and beyond are the first step in developing effective adaptation strategies and ways to capitalize on the associated economic opportunities. But, how these predictions are made must be driven by what decisions need to be made, and policy makers need mechanisms to influence how the science is done.

We have the means to collaborate with the local, state, and federal governments to address our pressing adaptation problems, but we must have better science. And, let me get better sleep at night.

Ben Kirtman, professor of atmospheric sciences, is the director of the Cooperative Institute for Marine & Atmospheric Studies at the University of Miami Rosenstiel School for Marine and Atmospheric Science and Program Director for Climate and Environmental Hazards at UM's Center for Computational Science.

“The Invading Sea” is a collaboration of four South Florida media organizations -- the South Florida Sun Sentinel, Miami Herald, Palm Beach Post and WLRN Public Media.