Climate change results in more intense hurricanes


Susan and her entire family waded from her house in Houston Texas to a neighbor’s home on higher ground the morning that Hurricane Harvey hit in late August. Susan Magee a 44 year old wife and mother of two recounts her story of being evacuated from her home in the wake of of torrential rains.  Waking up her girls and telling them to pack three outfits each was one of the easier parts from her experience. The harder ones were leaving everything except her family, pets, and legal documents. Leaving the only place her two daughters have ever called home. The one space where she and her husband lived together. She acknowledges that her home was not the most spectacular building ever built but says that she did not “mind spending their savings on the down payment” (Holter, 2017). After the devastating results of the storm that was thought to only bring a few inches of water into their home (Holter, 2017), Susan comments that for the meantime they will be staying in a hotel, and are living off of donations and gifts from friends including her friends and more extended family. She sums up her struggle of being in need of assistance and simultaneously proud, she speaks on behalf of her family, when she said that they will not be able to “rebuild our lives without the help of other people” yet at the same time, “we can’t do everything on our own” (Holter, 2017).

The Magees’ home is only one of an estimated 100,000 houses that were affected by Hurricane Harvey this past August (Fessler, 2017). In the wake of Hurricane Sandy, 352,000 people was allocated  $403 million in FEMA assistance (CNN, 2017).  Five years later, many families living on the east coast still cannot fix all of the damage done, in terms of of the thousands of homes completely destroyed, and 90 lives lost (Schlossberg, 2015, para. 3). While we can continually rebuild and replace buildings and homes, we cannot bring back the lives taken in these increasingly worse coastal storms. In the past 30 years, floods have killed more than 500,000 people globally, and displaced about 650 million (Michaels, 2016, para. 1). Hurricane Harvey’s damage is estimated to be about $190 billion in damages, while the costs of Irma are projected to reach $100 billion. These costs burden taxpayers as they entail disruption to business, transportation and infrastructure damages, unemployment periods for many lasting up to months, loss of goods and crop (including 25 percent of orange crop), increased fuel prices, and property damages (Wile, 2017).  The United States government cannot afford the associated costs of building and rebuilding in these increasingly flood prone regions, nor can taxpayers. Because of society’s communal connections to land and region, it is understandable as to why people have chosen to settle their homes and communities on the coast. We have always been infatuated with living close to the beauty of nature, and water systems in close proximity have helped to support communities for centuries (Wilson et. al, 2010).

Instead of trying to dictate over nature or institutions that are intended for communities to seek assistance in order to rebuild and replace, perhaps we should shift our efforts that keep us safe financially and through damages that effect loss of lives and livelihood (Revkin, 2017, Sec. 2). It is the consensus of the scientific community that we are seeing increasingly intense hurricanes due to our warming climate (GFDL, 2017). Coastal communities have reflected devastating costs and damages more than any other community. If we can understand this relationship of increasing hurricanes due to the state of our changing climate, we can be more proactive in our future actions surrounding coastal development. Given that climate change is intensifying hurricanes, we must change the National Flood Insurance program to discourage future building in areas that will be prone to more frequent floods.

In 1968 Congress created the National Flood Insurance program (NFIP) after a series of hurricane-induced disasters.  The federal government got involved in existing disaster assistance programs by providing financial support only if a flood was officially declared to be a major disaster for communities that could not afford to continually support themselves (Lee & Wessel, 2017, para. 3). The NFIP is a federally subsidized program administered by the Federal Emergency Management Agency (FEMA), that enables homeowners, businesses, and renters in participating communities to insure their property if it is at risk of flood damage (Lee & Wessel 2017, para. 2). It was originally planned also that the federal government would make insurance available only within communities that adopted and enforced orders to manage development in floodplains (Lee & Wessels, 2017, para. 4). It has three components: Hazard identification and mapping, Floodplain management criteria and mitigation, and flood insurance (Lee & Wessel, 2017, para. 3).  

Roughly 28.2% of the United States population lives in a coastal hurricane-prone regions according to American Society of Civil Engineers (ASCE) criterion (Crowell, et al., 2010) and half are adopting insurance policies.  The ASCE definition of hurricane-prone regions as areas in the US Atlantic Ocean and and Gulf of Mexico where the wind is more than 90 miles per hour as well as islands off our coasts including but not limited to Hawaii, Puerto Rico, and Guam (ASCE, 2006). While the rates of adopting flood insurance policies among coastal communities is high, it is much lower inland.

When considering how people are able to live in these flood prone coastal zones, origins dates back to development and settlement in the coastal regions of the United States. Floodplain areas, or low-lying areas subject to flooding from a nearby waterbody, were advantageous to inland agricultural communities as a means of irrigation. For economic benefit, large cities were built near rivers and coastlines. This is because residents benefited from lower transport costs since they were close to ports and any trade that occurred there. In modern times we have improved transportation methods which makes this advantage obsolete (Michaels, 2016). Taking this into consideration, many people have lived in these areas for a long time, making it difficult to stop development in these areas where people live (Wile, 2017)

Additionally, the NFIP has incentivized living in these areas, making it not only possible to live here, but an attractive option. When people’s homes get destroyed they are simply able to rely on their flood insurance to rebuild their properties every time they there is damage (Lee & Wessel, 2017, para. 14).  The NFIP incentivizes this by offering low premium rates to those who need to insure their homes against flood damage. Federal funding easily repairs damages, the communities there are very resilient, and are able to keep rebuilding themselves to stay there.

The original objectives of the NFIP were to prevent unwise floodplain development through zonal mapping  ensure that property owners could receive coverage at a reasonable cost, get a large number of communities and property owners to buy insurance, and finally to base premiums on federal assessments of flooding risk so people would be aware of and bear the cost of choices they make (Lee & Wessel, 2017).

Most NFIP insurance policies are sold and run by private insurers under FEMA’s Write Your Own (WYO) program. The WYO is a program designed for FEMA and private insurers to collaborate, under FEMA’s rules and regulations. WYO allows the involved insurers to write and service the Standard Flood Insurance Policy (SFIP) in their own names. As agents of the federal government, the insurers receive an expense allowance for policies and claims processed while the federal government is responsible for underwriting losses (FEMA, 2017 & Marker, 2012). It is important to note that these insurers primarily serve an administrative function. This is a potential flaw with the NFIP because it means they do not bear the burden and associated risks with actually paying insurance claims (Lee & Wessel, 2017). This is problematic because they might be less cautious about building in flood-prone regions.

One issue making it difficult to disinvolve the NFIP from coastal development is the NFIP’s grandfathering rules. Grandfathering ensures that properties re-categorized as being at a higher risk of flooding under revised flood insurance maps will not be subject to large increases (Insurance Information Institute, 2017). Redrawing the flood-risk lines on insurance maps did not affect the low rates of insurance regardless of higher risk zone assessment (III, 2017).

While the NFIP has provided some coastal protection by providing incentives for new homes to be elevated above surge levels as well as strengthening buildings against windstorm damage, there still has been no solution to adapt to issues of increasing of sea level rise and increase of more intense hurricanes (Leathermann, 2017). It is due to lack of strict regulation by the NFIP, that there has been uneven enforcement of building restrictions on the floodplain (Revkin, 2017).

By making insurance for property in coastal regions readily accessible and appealing, the NFIP has led to a large amount of coastal development. The NFIP provides insurance at sizeable discounts for homes and other buildings constructed in flood-prone areas (Kristian, 2017, para. 4). This flood insurance is a federal mandate to have a mortgage in these zones (FEMA, 2017). One proposed idea is an increased premium price to cover and reflect the high risk of floodplain construction (Kristian, 2017, para. 6). This would then discourage vulnerable building plans among those who cannot afford to cover the cost of storm damage. As a result of more people being able to afford insurance in these areas, we have seen more properties being damaged by repeated flooding by increasingly intense hurricanes (Michaels, 2016, para. 3).

Hurricane intensity or severity are defined in a couple of ways. Firstly, we use the category or Saffir-Simpson scale of the hurricane, which is measured by the intensity of winds at the event on a scale of 1 to 5. Storm surge can be used to measure intensity as it examines an abnormal rise in water level on a coast. It is the water from the ocean that is pushed toward the shore by the force of the winds swirling around the hurricane. This advancing surge combines with the normal tides and can increase the water level by 30 feet or more. Storm surge combined with waves can cause extensive damage(US Department of Commerce, National Oceanic and Atmospheric Administration, 2011). Meanwhile, having a landfall hurricane means the eye of the storm reached land (Nosowit, 2012). When examining Sea surface temperature (SST) we found that it is a measurement of energy levels on the top layer of the ocean due to the movement of molecules. Spaceborne measurements give us a global measurement of sea surface temperatures (US Department of Commerce NOAA, 2011). Sea level rise (SLR) is the rise in global sea levels due to increase in temperature caused by release of greenhouse gasses as a result of fossil fuel combustion. The warming atmosphere transfers heat to the ocean’s surface waters and expands its volume (Ocean Health Index, 2017).With a better understanding of the connection between climate change and hurricane intensity, we will be able to implement the steps needed to prevent the associated economic, social, and environmental damages. In order to gain this deeper understanding, the scientific community considered various measures such as increasing SSTs, sea level rises, and landfall hurricanes.

Linear correlation showed there was a significantly high chance (82%) that global temperature  (GT) was causing an increase in SST. When it was tested inversely, for increased SST causing change in GT, it had an insignificant 31% of causality, much lower compared to the other way around. This statistic shows that there is a very high chance warmer global temperatures cause increased Atlantic SST (Elsner, J., 2006). Elsner (2006) explains that as climate change heats the Earth, the seas warm up and store significant amount of energy, which is converted to hurricane wind. This means that with climate change warming global surface temperatures, SSTs are then raised as a result. This increase is SST also has a significant effect on hurricanes. The rise in SST is causing more intense hurricanes. Major hurricanes, which are a Category 3 or higher on the Saffir-Simpson scale-which measures wind speeds to measure potential property damage (NOAA) , may intensify in response to the warming SST associated with global warming (Mousavi et al, 2011). They state that there is an average 8% increase in hurricane intensity for every 1 degree celsius of SST rise (Mousavi et al., 2011, p. 577). These results also indicate that local sea surface warming was responsible for 40% of the increase in hurricane activity relative to the 1950–2000 average between 1996 and 2005, which proved this to be a notably big increase (Saunders and Lea, 2008). This means that tropical hurricanes on Atlantic are extremely susceptible to intensity increase and frequency, with an increase in SST. This leads us to believe an increase in Climate change and GT, is causing more intense hurricanes overall.

Sea Level Rise (SLR) plays a huge role in hurricane intensity. SLR projections show that catastrophic ice-sheet melting, as a result of climate change, estimate SLR increases of 1 m or more over the next century (Mousavi et al. 2011).  This increase in SLR can mean one thing, more fuel for hurricanes and more water for the hurricanes to help the formation of floods. The storm surge is difference in water from normal to flood height (NOAA, 2017). Landfall hurricanes become increasingly dangerous as water is added to create flooding. An increase in SLR will give them the storm surge they need to cause more deadly floods. Balaguru. Et al. (2015) shows there is a 90% increase in storm surge due to SLR when looking at the projection from the Sea, Lake and Overland Surges from Hurricanes(SLOSH) projection. This means the intensity of storm surge in mainly dependent on, and worsened by increasing sea level.  This increase in SLR leads to more storm surge, which in turn causes more floods. A study shows between 1970 and 1999 the highest amount of fatalities during a hurricane was from floods. It also showed floods contributed in approximately 59% of the fatalities during hurricanes (Kaye, 2008).

With climate change leading to both more intense hurricanes and more SLR, we can only expect the number of fatalities and damages to go up from here. If the predictions and the projections are true, the more intense storms with higher SSR will keep doing more damage if we keep on building these coastal communities. As it currently stand there is an average of 28 Billion dollars against an 18 Billion dollar budget (CBO, 2017, slide 4). The projections show this number is going to increase and is going to be a 39 Billion dollars worth of damage versus a 24 Billion dollars budget (CBO, 2017, slide 4). That is why it is crucial to move people away from coastal areas to more inland.

One of the first actions to take is to improve floodplain maps to more accurately describe the flood risk and extent of the floodplain. Floodplain mapping is defined as a system in which the height of the 100-yr flood is estimated with at least a confidence interval of 50%, but the higher the confidence interval level goes the more accurate, more reliable and overall better the map would be (Burby, 2001). Floodplain mapping can help identify the safe locations. This will reduce and discourage development in the remainder of floodplain. One issue is that currently FEMA does not incorporate climate change projections or sea-level rise in their flood insurance maps. As it stands, they state their policy does not map flood hazards “based on anticipated future sea levels or climate change” and that “over the lifespan of a study, changes in flood hazards from sea level rise and climate change are typically not large enough to affect the validity of the study results” (FEMA 2017).  If Federal Emergency Management Agency flood maps incorporated future climate conditions, it would send a ripple effect into real estate and insurance markets. This would be something the public would have to acknowledge. If the federal government made it a legal requirement to have projected climate conditions to be considered in the flood insurance risk maps, construction practices would change to be more precautious (Revkin, 2017). Of course mapping these floodplain areas can also spread awareness. By mapping these and showing them to the community, they can be aware of the dangers, risks and consequences of building in these areas. So instead of doing the cheaper option, they can go the safer way.

People in hurricane zones are able to pay the cheap insurance premium and get subsidized in return after the hurricane damage. These cheaper insurances discourage people to build in other safer area but it prompts them to rebuild in the same area. Enforcing higher flood insurance premiums makes it more difficult to get federal disaster assistance, while reflecting the actual damages (Flavelle, 2017). There is evidence of insurance policies going more towards this direction. In 2012 congress passed the Biggert-Waters Insurance Reform Act, which aimed to extend the National Flood Insurance Program (NFIP) for five years (Kunreuther & Michel-Kerjan, 2017). The main focus of this extension was placing more of the insurance risks onto coastal property owners. When it gets more difficult and more expensive to get federal insurance, the more individuals and local officials would care about where to build, therefore building less in flood risk areas. As it is, when insurance premiums are too low and do not reflect the actual risk of loss, a resulting subsidy on the coastal development encourages people to support sprawling floodplain building (Burby, 2001). This is what we are currently witnessing in coastal communities, and we see it reflected in the sizable 28.2% of the United States population currently living in these coastal regions (Crowell et al. 2010). If they were able to raise the cost, that incentive would be removed. The NFIP cannot accommodate the future scale of  flood damages that are rapidly increasing under a changing climate; a study commissioned by FEMA to help it gain better understanding of this (AECOM 2013) has shown that existing 1% flood hazard zones are fundamentally underestimated given ongoing climatic change (Shively, 2017). Making the insurances more inaccessible, more difficult to get and more expensive would eventually help the community. With more difficult to attain insurance, people will be urged to build in safe floodplain areas, discouraging further development in flood zones. (Flavelle, 2017; Burby 2001). If it becomes unattainable, development will be forced more inland.

There is no doubt that raising premiums and making insurance less accessible will be difficult to pass initially. This is because homeowners will not want their insurance costs raised, and homebuilders will not want to be out of business if coastal development is discouraged. For homeowners, if the premium is raised they might benefit from moving to a safer region inland. In doing this, we believe that the burden of losing their belongings and endangering their families will be eased. While many items can arguable be replaced by insurance, there are a fair amount of things that are irreplaceable. They also will not suffer from the economic loss of unemployment periods, associated with the damage from hurricanes in these flood regions (Wiles, 2017). As for homebuilders, if the rates increase they might lose money at first. Everyone moving away from the coastal communities and less people building near the coast will have an impact on them in the beginning, but over time they would have more chances to build bigger and better complexes away from the flood risk without their building and houses being destroyed. It can also provide the homebuilders with a safe community they can live in themselves with their families (Friedman & Scism, 2017).

We propose that the package of bills proposed by the House Financial Services Committee, pushed by Chairman Jen Hansarling (R-TX) be passed into law. The bill package would renew the NFIP program for five years. It would also enact the raise of insurance premiums, which we advocated for. In doing so it would make coverage more expensive for policyholders, and make it easier for private companies to sell their own flood insurance policies (Lee & Wessel, 2017). We also propose the passage into law of the House and Senate backed bill called; Sustainable, Affordable, Fair and Efficient (SAFE) NFIP Reauthorization Act. This bill supports what we suggested as it calls for greater investments in flood risk mapping and risk mitigation (Lee & Wessel, 2017).


Amir Entekhabi – Environmental Science

Rachel Finn – Natural Resource Conservation

Keren Radbil – Agricultural and Environmental education



Burby, R. J. (2001). Flood insurance and floodplain management: the US experience. Global Environmental Change Part B: Environmental Hazards, 3(3), 111-122. DOI 10.1016/S1464-2867(02)00003-7.

Congressional Budget Office. (2017). Effects of Climate Change and Coastal. Retrieved from:

Development on U.S. Hurricane Damage: Implications for the Federal Budget. Retrieved from:

Crowell, M., Coulton, K., Johnson, C., Westcott, J., Bellomo, D., Edelman, S., & Hirsch, E. (2010). An estimate of the US population living in 100-year coastal flood hazard areas. Journal of Coastal Research, 201-211. DOI 10.2112/JCOASTRES-D-09-00076.1

Effects of Climate Change and Coastal Development on U.S. Hurricane Damage: Implications for the Federal Budget. (2017, November 02). Retrieved December 04, 2017, from

GFDL. (2017). Global Warming and Hurricanes. Retrieved from:

Friedman, N., & Scism, L. (2017, October 23). What Could Raise Hurricane Irma’s Costs? Letting Contractors Handle Claims. Retrieved November 29, 2017, from

Flavelle, C. (2017). Hurricanes Highlight Failure to Enforce Flood Insurance Rules. Bloomberg Businessweek. Retrieved from:

Fessler, P. (2017, September 01). At Least 100,000 Homes Were Affected By Harvey. Moving Back In Won’t Be Easy. Retrieved December 04, 2017, from

Holter, L. (2017, August 31). I Lost My Home In Hurricane Harvey. Retrieved December 04, 2017, from

Hurricane Sandy Fast Facts. (2017, October 19). Retrieved December 04, 2017, from

Insurance Information Institute. (2017). Retrieved from:

Kristian, B. (2017). The Week. Retrieved from:

Kaye, K. (2008, July 12). Inland flooding causes most hurricane deaths. Chicago Tribune. Retrieved from:

Leatherman, S. P. (2017). Coastal Erosion and the United States National Flood Insurance Program. Ocean & Coastal Management. Chicago. DOI 10.1016/j.ocecoaman.2017.04.004.

Lee, V., & Wessel D. (2017). “The Hutchins Center Explains: National Flood Insurance Program.” The Brookings Institution. Retrieved from:

Michaels, G. (2016). The Conversation. Retrieved from:

Marker, S. (2012). What Is The Write-Your-Own Insurance Policy Program? Merlin Law Group. Retrieved from:

Nosowitz, D. (2012, October 29). The Dictionary Of Hurricane Sandy: Landfall. Retrieved October 20, 2017, from

Revkin, A. (2017). Rethinking the ‘Infrastructure’ Discussion Amid a Blitz of Hurricanes. ProPublica. Retrieved from

“Saffir-Simpson Hurricane Wind Scale.” National Hurricane Center, NOAA,

Schlossberg, T. (2015). New York Today: In Hurricane Sandy’s Wake. Retrieved from

Shively, D. “Flood risk management in the USA: implications of National Flood Insurance Program changes for social justice.” Regional Environmental Change 17.6 (2017): 1663-1672. DOI 10.1007/s10113-017-1127-3.

US Department of Commerce, National Oceanic and Atmospheric Administration. (2016, September 04). What is storm surge? Retrieved November 29, 2017, from

Wile, R. (2017).

Kunreuther, H., & Michel-Kerjan, E. (2017, November). Implementing the National Flood Insurance Reform Act in a New Era of Catastrophes. Retrieved November 15, 2017, from


Leave a Reply

Your email address will not be published. Required fields are marked *