What Will be Global Warming’s Effect on Hurricanes in the Future?
Abstract
The trends of hurricanes in recent years are believed to be increasing surpassed the strengths and amounts of previous accounts. Is global warming the reason why? Research gathered from the National Oceanic and Atmospheric Administration (NOAA)[1, 2] was analyzed in multiple forms to develop an understanding of the possible relationship between the pair. Global warming was perceived to have a striking, but a prominent connection to the numbers and strengths of hurricanes. As a result, the hurricane count and Accumulated Cyclone Energy (ACE)[5] follows the format of a sine function. The impending, temporary decrease in storms will be very misleading, just like how global warming has been. This study is considered evidence of global warming’s effect on the recent increases in hurricane damages.
Introduction
In response to a recent analysis of the most destructive hurricanes witnessed by America, a writer for The Balance, Kimberly Amadeo[8] notices, “…that 17 of them have occurred since 2000.” But is global warming the reason why?
Researchers have different answers to this question. Some say the number of hurricanes would hardly increase compared to the amount of damage each one is capable of [9]. Others argue that anthropogenic warming would create a more substantial atmospheric moisture content so that each hurricane would have more rainfall [6]. And of course, some do not see any relation.
It is evident that hurricanes cause tremendous damage. For starters, “Over one-third of its [America’s] gross domestic product is from states along the Gulf and Atlantic coastline,” Amadeo continues [8]. And hurricanes cause increases in unemployment rates and depressions in the stock market. For example, in 2005, Hurricane Katrina damaged 19% of the oil production in the United States. Even though it was only a CAT level 3 cyclone when it hit land, about 125 billion dollars were spent in repair, and 15 million people were affected.
Despite the damage hurricanes create every year, ironically a majority of the last 3% of Americans still split on whether to believe in global warming are from Florida and Texas; the two states hit most by hurricanes since 1851. And shockingly, a poll by the Yale Program on Climate Communication concluded, “Most people know climate change is happening, and a majority agrees it is harming people in the United States. But most don’t believe it will harm them.”
Because this idea is relatively new, the first goal of this study is to determine the relationship between global warming and hurricanes. And secondly, what this means for the future of the hurricane season. The hypothesis states, ‘If the difference in the sea and air temperature continues to increase, then the number and strength of hurricanes will increase at nearly the same rate.’ Four stages were performed to test this.
Methods
It is already well understood by most scientists in this field that global warming causes the ocean temperature to increase. But as an extra measure of assurance, levels of CO2 credited by NASA[3] were compared to the increase in ocean temperature measured by NOAA[2]. Again, it was evident with a high Pearsons coefficient that increases in CO2 in the atmosphere are the sources of increases in ocean temperature.
1. Preparation. Hurricanes form from the difference in temperature between the ocean and the atmosphere because of the convection currents that develop over the sea. So, the ocean and air temperature[2] was used to create the temperature difference between the two. The ocean temperature is the minuend, and the air temperature is the subtrahend because hurricanes form from the ocean being higher than the air temperature — not the other way around. And even though these temperatures were global values, they still provided the relative difference that would cause convection currents.
The hurricane[1] and temperature data was block-averaged to remove the small weather variations that could be distracting from a result with high correlation. This process included taking medians of data that were grouped by the decade. Specific years that are referenced are named by the starting year in that decade set.
2. Linear Correlation. Linear functions were made to show the correlation between global warming and hurricanes. The y-values were named storms, hurricanes, major hurricanes, and ACE. The temperature difference was the x-value. The Pearsons coefficient was used to measure the correlation in each graph.
3. In the Future. To find out what the hurricane season would be in the future, time was made the new x-value, and the temperature difference was made a y-value. The reason why time was the x-value for this step is to look strictly at hurricanes over time and into the future. So despite what the correlation between global warming and hurricanes is, the best possible prediction can be made for the future.
But, it was observed how a linear model was an under-fitting of the blocked data. A sine function seemed to fit best in every graph. So sine functions were created in every category. These sine functions were adjusted to the data by hand and not by a computer algorithm.
4. The Check. A check was also performed to ensure the accuracy of each conclusion. As if the year was 2006, the second set of sine functions were made in each category. The idea of making 2005 the final point for the check graph was a purposeful choice. The years 2005 and 2017 were both a significant spike in hurricane activity, so 2005 was a recent year that could adequately mimic 2017. The observations were used to compare the real answers to the predicted results.
To further refine the data, in the future, a computer algorithm should be built to better perfect upon the trigonometric functions presented here. As well, more years of information would create a better study overall; however, the trends are powerful enough to promote action and necessitate the continuation of research.
Results
In linear correlation between global warming and hurricanes, the Pearsons coefficients were only in the range from 0.2435 to 0.6474. This range makes global warming’s effect on hurricanes hesitant and therefore, just plausible. This linear correlation is an under-fitting of the data but, this statement is supported by the crests and troughs of each sine function because they are not synchronized perfectly. Still, the relative idea of hurricanes following the pattern of a sine function is a trustworthy statement.
Each sine function follows a pattern along the lines of decreasing for about 30 years and then increasing for about 4 years longer. Each category below was studied over time.
As shown in the key, the data points in blue are the block averaged data by the decade. The values in green make up the most current sine function to predict future hurricane activity. The orange sine function is the check function. It shows what the prediction of hurricane activity would have been in 2006. The slope values of the 2006 function in comparison to the 2018 function are not overlapping which is why specific predictions using these functions have fairly significant error rates.
The tables below reflect conclusions from the graphs above.
Discussion
It is only plausible to suggest that global warming is the sole reason why the linear hurricane season model is increasing. This is due to the unsynchronized sine functions throughout each graph. Around 1950, for example, there is a crest in the ACE graph, but the peak for named storms occurred slightly earlier. And even earlier in the temperature difference graph.
But the dominant discovery found from this study is the pattern that hurricanes follow. Even though the sine function is used very commonly to represent trends in the environment, it was never used to describe tropical storms before this study.
Shockingly, around the 2018 decade is the next crest for hurricane seasons. So this suggests that the values and strengths of hurricanes will decrease for the following 30 years, approximately. Even though the sine functions have positive slopes, this contradicts the idea that hurricanes will increase in number and strength in the immediate future. With this being said, the apparent spike in hurricane activity that many have noticed in the past is support for this sine function.
Linearly, this results in only 1°C raising a season of ACE by 1 which increases the numbers of named storms by 0.2 for every 5.2 years. This does not seem like a compelling discovery, but this is leaving out the characteristics of the sine function. At the moment, the 2018 decade is the most recent crest of the hurricane functions, so the number of storms will decrease for another 30 years or so. Hurricanes will be brought out of the head of the discussion. This makes hurricanes very misleading, just like global warming.
The message to be taken from this is not to be misled by a decrease in the number of hurricanes because a decreased ACE of 78 (this is just under the strength of Hurricane Katrina) over 31 years is only temporary. The ACE will then increase by 91 for the following 32 years. But when summarized linearly, the ACE will only increase by 13 over the next 63 years.
This does not sound like much over 63 years because the subtle incline of hurricanes may not be perceived. But, this could mislead us into more procrastination dealing with global warming and other environmental issues. According to The New York Times[7], “Global warming is precisely the kind of threat humans are awful at dealing with: a problem with enormous consequences over the long term, but little that is sharply visible on a personal level in the short term.” Despite mounting evidence of the effects of global warming, we have been slow to act. This has been the reason for global warming, and now the increase of hurricanes as well. Not the lack of technology, workforce, or effort, but a lack of motivation. When the number and severity of tropical storms later rise, future generations will pay a steep price for our procrastination. An investment of money and human resources today would reduce costs of future hurricane damage.
Conclusions
During this study, data that was gathered from the National Oceanic and Atmospheric Administration[1, 2] was used to correlate global warming’s effect on hurricanes. As a result, the correlation between global warming and hurricanes is only a probable result because the Pearsons coefficients comparing both values was not high enough to be a confirmed statement. But the critical idea of representing the patterns of hurricanes with a sine function is yet to be done in this way, before this study. So even if the model is yet to be 100% reliable, this pattern begs the question of how hurricanes will be interpreted in the future.
Compared to the few other ideas to first relate these topics together[6, 9], there was never a result of an impending decrease in the number of hurricanes and their strengths; even though the function is positive overall. Because of the mixed theories, this study was presented as another way to interpret the recent focus on hurricane damage. Unlike how others have pictured, the numbers and strengths of hurricanes will decrease as well as increase. The conclusion of this study demonstrates the pathways of tropical storms in the future as well as the relative relationship to global warming.
The initial goal of this experiment was to address our efforts against global warming, specifically hurricanes because they are the most damaging natural disasters in the world. This goal is still expressed after the experiment has been run, but with a different message. Hurricanes are destructive, and just like global warming, the point of harm comes at such a slow rate, it almost becomes irrelevant to the mind. It has taken 30 years of convincing for global warming, and this will may be true for hurricanes as well. Unfortunately, this would be precisely when the numbers start to spike positively again.
With the energy of 10,000 nuclear bombs, and set to increase, hurricanes are powerful and misleading.
Appendix
Hurricane Season. Atlantic Hurricanes have been recognized for their unquestionable strength and endurance upon hitting landfall. This strength is measured as Accumulated Cyclone Energy (ACE), a unit used specifically for measuring hurricanes. This value classifies a hurricane season. For reference, an above-normal season must have an ACE higher than 111 whereas, a below-normal season has an ACE no larger than 66.
How Do Hurricanes Form? An eastern wave of dust and sand particles on the Sahara Desert blows westward across the Atlantic Ocean. Meanwhile, small convection currents start to form due to the differences in air temperature. The humid air coming off the ocean’s surface (at a minimum of 26° C), rises towards the colder air that rushes downward to fill its place. Then the water vapor clings to the dust and sand particles to form clouds. The convection currents speed up, and the clouds turn into thunderstorms. Lastly, the clouds start to spin due to the earth’s counter-clockwise rotation. Depending on the wind speeds, the cyclones are given different titles.
References
[1] Landsea, Chris, and National Oceanic & Atmospheric Administration . “The Atlantic Hurricane Database.” Hurricane Research Division, Atlantic Oceanographic and Meteorological Laboratories, 1 June 2017. Web. Apr 2018, http://www.aoml.noaa.gov/hrd/tcfaq/E11.html.
[2] National Oceanic & Atmospheric Administration . “Average Global Sea Surface Temperature.” Climate Change Indicators, Environmental Protection Agency, Aug. 2016. Web. Apr. 2018, https://www.epa.gov/sites/production/files/2016-08/sea-surface-temp_fig-1.csv.
[3] “Global CO2 Mixing Ratios.” Managed by Randall Jackson, Global Climate Change, NASA, 28 Mar. 2018. Web. Apr. 2018, https://climate.nasa.gov/vital-signs/carbon-dioxide/.
[4] Leon, Nancy, and Kristen Erickson. “How Do Hurricanes Form?” Nasa Space Place, NASA, 7 Mar. 2018. Web. Apr. 2018, https://spaceplace.nasa.gov/hurricanes/en/.
[5] “Accumulated Cyclone Energy.” Wikipedia, Wikimedia Foundation, 8 Apr. 2018. Web. Apr. 2018, https://en.wikipedia.org/wiki/Accumulated_cyclone_energy.
[6] “Global Warming and Hurricanes.” Geophysical Fluid Dynamics Laboratory, National Oceanic and Atmospheric Administration, 24 Jan. 2018. Web. Apr. 2018, https://www.gfdl.noaa.gov/global-warming-and-hurricanes/.
[7] Popovich, Nadja, et al. “How Americans Think About Climate Change, in Six Maps.” The New York Times, The New York Times, 21 Mar. 2017. Web. 22 Dec. 2017, https://www.nytimes.com/interactive/2017/03/21/climate/how-americans-think-about-climate-change-in-six-maps.html.
[8] Amadeo, Kimberly. “How Hurricanes Damage the Economy.” The Balance. N.p., 14 Dec. 2017. Web. 31 Dec. 2017, https://www.thebalance.com/hurricane-damage-economic-costs-4150369.
[9] Byrd, Aaron, Alexandra Garcia, and Henry Fountain. “How Do Hurricanes Happen?” The New York Times. The New York Times, 16 Nov. 2013. Web. 23 Dec. 2017, https://www.nytimes.com/video/science/100000002555638/the-future-of-storms.html.
