Author Archives: Paul Wilson

About Paul Wilson

Vice President, Model Development, RMS
Paul Wilson is a vice president in the RMS model development team leading the ongoing development of the RMS North Atlantic Hurricane and Storm Surge Models. Paul has a MSc. in Physics and a Ph. D. in Atmospheric Physics both from Imperial College London where his research focused on the application of extreme value statistics in the climate system and the impact of long‐ranged correlations on extreme events.

Irma Impacts in the Caribbean

13:30 UTC  Thursday, September 7

Paul Wilson, vice president – Model Development, RMS

This morning, the RMS Event Response team has started to assess major damage in the Caribbean caused by Hurricane Irma, which has become the strongest Atlantic hurricane on record.

Our preliminary modeling for the Caribbean provides insights into the potential range of damage outcomes for each island that we understand to be impacted, including Antigua and Barbuda, British Virgin Islands, Anguilla, Saint Maarten and Saint Martin. It is already clear that damage ratios are high, particularly in Barbuda.

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After Matthew: Putting a Value on Natural Coastal Defenses

As coastal communities in the U.S. continue to clear up and count the costs following Hurricane Matthew, we already know things could have been much worse. So, had the storm not weakened and veered off into the Atlantic but made direct landfall as a major hurricane would the infrastructure and coastal defenses along the south-east coast of the U.S. have held up? Or could we have been better prepared? One element often overlooked is that of natural coastal defenses, such as salt marshes and wetlands.

While it’s still early days, it’s clear these natural ecosystems played a role in shielding Georgia and the Carolinas from some of the damage that Matthew inflicted. We can see these effects in the details of our reconstructions of Matthew’s storm surge footprint, but also because of some related research we’re publishing just today that for the first time puts an actual economic value on the protective effect of natural coastal defenses.

Matthew’s surge was greater than 6 feet (1.8m), according to the National Weather Service, when it made landfall about 55km northeast of Charleston on October 8 as a Category 1 storm. Wetlands – such as those around Savannah and Charleston – would have taken the brunt, slowing down the force of the water and offering urban areas some protection against inundation from the sea. Because of the new study we’re now able to express the value of this protection in dollars.

Hurricane Sandy flooding

The study, Coastal Wetlands and Flood Damage Reduction was led by the University of California, Santa Cruz, The Nature Conservancy, and the Wildlife Conservation Society in partnership Guy Carpenter, Lloyd’s, and RMS. We contributed cutting-edge modeling expertise. The research looks back to Hurricane Sandy, which hit New York and New Jersey particularly hard in 2012, although its effect was felt across large swathes of the Eastern Seaboard. The study concluded that:

  • Over $625m in property damage was avoided, with coastal wetlands providing a 10% reduction in property damages across states on average;
  • In New Jersey, wetlands prevented an estimated $425m in losses;
  • The protective value of wetlands during Sandy was nearly 30% in Maryland.

Although the protections offered by features such as wetlands, salt marshes and barrier reefs are already captured by RMS catastrophe models, this was the first time we’d extracted, isolated and measured their unique role. This capacity to better understand and quantify the economic value of natural defenses is a critical tool for policymakers, conservationists and the insurance industry, particularly in regions where wetlands are being degraded.

At RMS we anticipate that macro trends, such as sea level rise, will inevitably elevate the role of natural wetlands in the future. While the jury is still out on how climate change will impact the frequency and severity of hurricanes in the North Atlantic, the Intergovernmental Panel on Climate Change (IPCC) anticipates we will see more weather extremes by the end of the century.

In its 2013 report the IPCC predicted that it was “more likely than not” that the number of the most intense storms will increase in certain parts of the world. And even without any significant change in windstorm severity, sea level rise can be expected to drive up coastal storm losses.

According to Risky Business: The Economic Risks of Climate Change in the United States, a 2014 initiative led by former New York Mayor Michael Bloomberg and former U.S. Treasury Secretary Henry Paulson (and supported by RMS modeling), higher sea levels combined with storm surge will increase the average annual cost of coastal storms along the Eastern Seaboard and the Gulf of Mexico by $2 billion to $3.5 billion in just 15 years.

Better understanding the financial benefits of natural coastline features will ultimately help communities build greater resilience to future storms and floods and to attract more funding for sea defense conservation and restoration. The necessary response may be driven by science and gradual sea level rise. Or it may come only after major catastrophes have done their damage in the future.

The Rising Cost of Hurricanes – and America’s Ability to Pay

Future hurricanes are going to cost the U.S. more money and, if we don’t act to address this, it will leave the government struggling to cope. That is the finding of a recent Congressional Budget Office (CBO) report which put it starkly:

“…over time, the costs associated with hurricane damage will increase more rapidly than the economy will grow. Consequently, hurricane damage will rise as a share of gross domestic product (GDP)…”

The CBO identified two core drivers for the escalating costs: climate change, which will drive just under half of the potential increases in hurricane damages while just over half of damages will come from coastal development. The four main four variables that would have the most impact were identified as:

  • Changes in sea levels for different U.S. states;
  • changes in the frequency of hurricanes of various intensities;
  • population growth in coastal areas, and;
  • per capita income in coastal areas.

Using Catastrophe Models to Calculate the Future Cost of Hurricanes

To inform the CBO’s research and creation of a range of possible hurricane scenarios based on future changes to the four key variables, RMS hurricane and storm surge risk experts provided the CBO with data from the RMS North Atlantic Hurricane Model and Storm Surge Model.

Through RMS’ previous work with the Risky Business Initiative we were able to provide state specific “damage functions” which were used to translate possible future hurricane events, state-specific sea levels and current property exposure into expected damaged. While we usually produce loss estimates for catastrophes, we didn’t provide the CBO with estimated losses ourselves – rather we built a tool so the CBO could “own” its own assumptions about changes in all the factors – a critical aspect of the CBO’s need to remain impartial and objective.

Solutions to Increase Coastal Urban Resilience

The CBO’s report includes suggested policies that could decrease the pressure on federal spending. The polices range from global initiatives to limit greenhouse gas emissions to more direct mechanisms that could shift costs to state and local governments and private entities, as well as investing in structural changes to reduce vulnerabilities. Such approaches bring to the forefront the role of local resilience in tackling a global problem.

However, therein lies the challenge. Many of the options open to society to increase resiliency against catastrophes, could have a less positive effect on the economy. It’s an issue that has been central to the wider debate about reducing the impacts of climate change. Limiting greenhouse gas emissions has direct effects on the oil and gas industry.  Likewise, curbing coastal development impacts developers and local economies. It has led states such as North Carolina to ban the use of future sea level rise projections as the basis for policies on coastal development.

Overcoming Political Resistance

Creating resiliency in U.S. towns and communities needs to be a multi-faceted effort. While initiatives to fortify the building stock and curb global climate change and sea level rise are moving ahead there is strong resistance from the political arena.  To overcome the resistance, solutions to transition the economy to new forms of energy must be found, as well as ways to adapt the current workforce to the jobs of the future. City leaders and developers should partner to find sustainable growth initiatives for urban growth, to ease the fears that coastal cities will wither and die under new coastal use restrictions.

Initiating these conversations will go a long way to removing the barriers to success in curbing greenhouse gas emissions and limiting coastal growth. With an already polarised political debate on climate change this CBO report may provoke further controversy about how to deal with the factors behind the increase in future hurricane damage costs. Though one conclusion is inescapable: catastrophe losses are going up and we will all be footing the bill.

This post was co-authored by Paul Wilson and Matthew Nielsen.

Matthew Nielsen

Senior Director of Global Governmental and Regulatory Affairs, RMS

Matthew Nielsen leads Governmental and Regulatory Affairs. He is responsible for maintaining relationships with regulators, legislators, and rating agencies on behalf of the company to establish open channels of communication around RMS models and solutions. Matthew is a meteorologist and geographer with extensive experience in North American catastrophe risk. In his prior role at RMS, he was responsible for developing the RMS climate peril models for the Americas, including the severe convective storm, winter storm, flood, and hurricane models. He has conducted field reconnaissance for major catastrophes including Hurricanes Katrina and Sandy. Before joining RMS, Matthew conducted remote sensing in satellite meteorology research at the Cooperative Institute for Research in the Atmosphere (CIRA). He holds a BS in physics from Ripon College, where he won the Henry Knop Award in Physics, and an MS in atmospheric science from Colorado State University. Matthew is a member of the American Meteorological Society (AMS), the International Society of Catastrophe Managers (ISCM), and the American Association of Geographers (AAG).

Coastal Flood: Rising Risk in New Orleans and Beyond

As we come up on the tenth anniversary of Hurricane Katrina, a lot of the focus is on New Orleans. But while New Orleans is far from being able to ignore its risk, it’s not the most vulnerable to coastal flood. RMS took a look at six coastal cities in the United States to evaluate how losses from storm surge are expected to change from the present day until 2100 and found that cities such as Miami, New York, and Tampa face greater risk of economic loss from storm surge.

To evaluate risk, we compared the likelihood of each city sustaining at least $15 billion in economic losses from storm surge – the amount of loss that would occur if the same area of Orleans Parish was flooded today as was flooded in 2005. What we found is that while New Orleans still faces significant risk, with a 1-in-440 chance of at least $15 billion in storm surge losses this year, the risk is 1-in-200 in New York, 1-in-125 in Miami, and 1-in-80 in Tampa.

Looking ahead to 2100, those chances increase dramatically. The chance of sustaining at least $15 billion in storm surge losses in 2100 rises to 1-in-315 in New Orleans, 1-in-45 in New York, and 1-in-30 in both Miami and Tampa.

Due to flood defences implemented since 2005, the risk in New Orleans is not as dramatic as you might think compared to other coastal cities evaluated. However, the Big Easy is faced with another problem in addition to rising sea levels – the city itself is sinking. In fact, it’s sinking faster than sea levels are rising, meaning flood heights are rising faster than any other city along the U.S. coast.

Our calculations regarding the risk in New Orleans were made on the assumption that flood defences are raised in step with water levels. If mitigation efforts aren’t made, the risk will be considerably higher.

And, there is considerable debate within the scientific community over changing hurricane frequency. As risk modelers, we take a measured, moderate approach, so we have not factored in potential changes in frequency into our calculations as there is not yet scientific consensus. However, some take the view that frequency is changing, which would also affect the expected future risk.

What’s clear is it’s important to understand changing risk as storm surge continues to contribute a larger part of hurricane losses.

RMS and Risky Business: Modeling Climate Change Risk

Earlier this year, RMS partnered with the Risky Business Initiative, a year-long effort co-chaired by former New York City Mayor Michael Bloomberg, former Treasury Secretary Henry Paulson, and Farallon Capital founder Tom Steyer to quantify and publicize the economic risks the United States faces from the impacts of a changing climate.

The report, which launched today, has been widely covered in publications ranging from Fortune and The Wall Street Journal to The Hill. It builds on the best available scientific evidence, including both the Intergovernmental Panel on Climate Change (IPCC) and National Climate Assessments, to highlight the risks and cost a changing climate will bring to the business and financial communities the report addresses.

The report details the impact of climate change at the county, state, and regional level; it is the highly vulnerable coastal regions exposed to rising sea levels and the potential for changes in storm activity where RMS has been privileged to contribute our expertise and modeling.

RMS North Atlantic hurricane and storm surge models are based on a base climatology defined by the historical record of storms and represents the current state of the climate. Sea-level rise will increase the risks associated with storm surges and a changed climate may lead to changes in the frequency and intensity of hurricanes the impact the U.S. East Coast and Gulf States.

To address the potential impacts of such changes, RMS pulled together a cross-functional team from our model development group and consulting teams to implement the changes in storm frequency and sea-level rise in our model and analyze the impacts against our database of U.S. property exposure. The team worked with leading climate and hurricane experts and the Risky Business team to understand the latest scientific thinking and gather the information needed to adjust our model from the peer review literature.

In the space of just a few months, the team developed nearly 20 versions of our storm surge hazard model to reflect the expected increase in sea-level rise through the coming decades up to the year 2100, as well as the range of uncertainty captured by the latest IPCC assessment. In addition, the team developed several hundred alternative scenarios of hurricane frequency to model how hurricane frequency may evolve with different “Representative Concentration Pathways” used by the IPCC to describe possible climate futures, possible depending on how much greenhouse gas is emitted in the years to come.

The results of RMS’ analysis, quantifying the changes in losses to hurricanes and storm surges through the coming century have been fed into the Risky Business econometric modeling to quantify the cost to the U.S. economy.

Our analysis highlights that the sea-level rise alone – one of the most certain aspects of a warmer climate – has the potential to more than double the economic losses to hurricanes and storm surges by the end of the century if left unchecked.

RMS, along with Risky Business, recognizes that the analysis is not definitive; however, the potential costs can be quantified and the risks of in-action assessed. This collaboration has developed an invaluable database of information on the impacts climate change on hurricane risk, and by extension, the U.S. economy as a whole.

Just as the Risky Business Initiative hopes to promote a non-partisan discussion on the risks of climate change within the business and financial communities as a whole, RMS hopes that this work and our continued collaboration with the scientific community will lead to continued dialogue in the (re)insurance and catastrophe loss modeling community on the impact of climate change to our business.

Visit to view the full report.