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The frequency with which tropical cyclones (TCs) occur controls all other aspects of tropical cyclone risk since a storm that does not occur can do no harm. Yet this frequency is poorly understood. There is no accepted theory that explains the average number of TCs that occur each year on the Earth, nor how that number will change with global warming. Arguments based on global budgets of heat or moisture do not yet appear helpful, nor does a detailed understanding of the physical processes of TC genesis. Empirical indices that predict TC frequency as a function of large‐scale environmental variables can explain some of its relative variations in space and time, but not its absolute value. Global numerical models with horizontal grid spacings on the order of 25–50 km have allowed much improved simulations of TC activity, however. Many such models project a decrease in frequency with warming, but some project an increase. Idealized simulations, including those at higher resolutions, offer promise by allowing a systematic, deductive investigation of the roles of individual environmental factors. In addition to the larger‐scale environmental modulation of genesis likelihood, precursor disturbances, or "seeds", may exert an independent influence on TC frequency. Plain Language Summary: The term tropical cyclone frequency refers to the average number of tropical cyclones (also known as hurricanes, typhoons, etc.) which occur each year, either over the earth as a whole or in smaller regions. In this paper, the authors review the state of the science regarding what is known about tropical cyclone frequency. The state of the science is not great. There are around 80 tropical cyclones in a typical year, and we do not know why it is this number and not a much larger or smaller one. We also do not know much about whether this number should increase or decrease as the planet warms‐‐‐thus far, it has not done much of either on the global scale, though there are larger changes in some particular regions. No existing theory predicts tropical cyclone frequency. In this situation, we are left with numerical models as our primary tool, and the authors discuss the strengths, weaknesses, and different ways of using such models to investigate tropical cyclone frequency. Idealized simulations, in which the planet is made simpler than it really is, are allowing some new insights. Another promising avenue of investigation involves studying the weaker disturbances that sometimes strengthen into tropical cyclones. Key Points: We do not understand why the number of tropical cyclones per year is what it is, nor how it may be changingIn the absence of theory, our main tools are numerical modelsPromising research directions include idealized simulations at high resolution and study of precursor disturbances, or "seeds" [ABSTRACT FROM AUTHOR]

In this paper, we identified the following potential physical impacts of climate change on North Carolina (NC): a.) An increase in sea level would have a significant negative effect on the NC coastal region leading to flooding, erosion and increased salinity; b) Potential increases in intensity and/or frequency of Atlantic hurricanes will have direct, negative impacts on NC's coastal plain; stronger hurricanes will extend their reach to the Piedmont and mountains leading to heavy rainfall, possible flooding, and landslides in the mountains; c.) The temperature increase in NC is likely to be uneven due to the state's complicated physical geography and influences from atmospheric motion and processes in nearby states; d.) Other effects of rising temperatures are heat waves during the summer months, which will have significant impact on agriculture, health, and air quality. The impact of global warming on NC cannot be ignored or overestimated. For example, projections for Atlantic hurricanes are highly uncertain, and could therefore be easily under/over-estimated. More research is needed to improve the weather and climate models, computing facilities, and observations, so that effects of global warming on the weather in North Carolina, with its distinct geographical areas, can be identified and more precisely predicted. Recommendations for concrete actions are given. [ABSTRACT FROM AUTHOR]

Tens of millions of people around the world are already exposed to coastal flooding from tropical cyclones. Global warming has the potential to increase hurricane flooding, both by hurricane intensification and by sea level rise. In this paper, the impact of hurricane intensification and sea level rise are evaluated using hydrodynamic surge models and by considering the future climate projections of the Intergovernmental Panel on Climate Change. For the Corpus Christi, Texas, United States study region, mean projections indicate hurricane flood elevation (meteorologically generated storm surge plus sea level rise) will, on average, rise by 0.3 m by the 2030s and by 0.8 m by the 2080s. For catastrophic-type hurricane surge events, flood elevations are projected to rise by as much as 0.5 m and 1.8 m by the 2030s and 2080s, respectively. [ABSTRACT FROM AUTHOR]

This paper reviews recent research on tropical cyclones and climate change from the perspective of event risk—the physical behavior of storms; vulnerability—the characteristics of a system that create the potential for impacts, but are independent of event risk; and also outcome risk—the integration of considerations of vulnerability with event risk to characterize an event that causes losses. The paper concludes that with no trend identified in various metrics of hurricane damage over the twentieth century, it is exceedingly unlikely that scientists will identify large changes in historical storm behavior that have significant societal implications, though scientists may identify discernible changes in storm behavior. Looking to the future, until scientists conclude a) that there will be changes to storms that are significantly larger than observed in the past, b) that such changes are correlated to measures of societal impact, and c) that the effects of such changes are significant in the context of inexorable growth in population and property at risk, then it is reasonable to conclude that the significance of any connection of human-caused climate change to hurricane impacts necessarily has been and will continue to be exceedingly small. [ABSTRACT FROM AUTHOR]

In this paper, the possible connection between the frequency of Atlantic hurricanes to the climate change, mainly the variation in the Atlantic Ocean surface temperature has been investigated. The correlation between the observed hurricane frequency for different categories of hurricane's intensity and Sea Surface Temperature (SST) has been examined over the Atlantic Tropical Cyclogenesis Regions (ACR). The results suggest that in general, the frequency of hurricanes have a high correlation with SST. In particular, the frequency of extreme hurricanes with Category 5 intensity has the highest correlation coefficient (R =0.82). In overall, the analyses in this work demonstrates the influence of the climate change condition on the Atlantic hurricanes and suggest a strong correlation between the frequency of extreme hurricanes and SST in the ACR. [ABSTRACT FROM AUTHOR]

Thermophilization – changes in community composition towards greater relative abundances of species associated with warmer environments – has been described for plants and animals in many locations around the world. Disturbances of various kinds have increased rates of thermophilization in temperate sites, and this has been proposed, but not demonstrated, for some tropical environments. In this study, we tested whether disturbance by a category 4 hurricane in 1988 (Hurricane Gilbert) increased thermophilization in a Jamaican montane forest by using pre‐ and post‐hurricane data collected over four decades (1974–2014). We analysed tree species composition in permanent plots at ca 1580 m above sea level in Jamaica's Blue Mountains. There were 66 tree species with stem diameters ≥ 3 cm at breast height. We used published data on the altitudinal distribution of 62 species (94% of genetic individuals (genets)) to calculate the mean community altitude scores (MCAS) of the trees recorded in each census, as well as the MCAS of the survivors, recruits and dead trees after each decade. We found that thermophilization did occur (i.e. MCAS decreased significantly over time), and that this was due both to a decreasing MCAS of recruits through the four decades (significantly lower than expected in the last three decades) as well as a high MCAS of trees that died. Thermophilization was fastest in the post‐hurricane decade, during which time there was marked and significant increase in the MCAS of dead trees; this change was above and beyond expectations of long‐term successional dynamics. The rate of compositional change equates to an overall decrease in MCAS of 1.6 m yr−1 over the forty‐year study period. We conclude that this Jamaican montane forest is undergoing thermophilization (likely due to rising temperature) and that the hurricane‐caused disturbance accelerated thermophilization through differential mortality. [ABSTRACT FROM AUTHOR]

Compound wind and precipitation (CWP) extreme events can cause a significant increase in socio‐economic loss in coastal regions. This study investigated the potential impact of climate change on CWP events using Coupled Model Intercomparison Project model outputs for the coastal areas impacted by tropical cyclones on a global scale. We identified global hotspots of higher dependence between extreme wind and precipitation events. Under climate change, the results show a substantial increase in precipitation extremes compared to individual wind extreme events. The likelihood of CWP events under climate change indicates an increase (about 40%–50%) in most coastal regions in North Atlantic, East, and South Asia. The results of this study can help to identify hotspot regions under climate change and further assist in minimizing the impact of future disasters in vulnerable coastal areas. Plain Language Summary: Coastal regions are more densely populated than the hinterland and continue to focus on economic activity and development. Coastal areas are often exposed to compound wind and precipitation extreme events in hurricane‐prone regions, causing significant socio‐economic losses compared to individual events. Increased compound events will bring higher risks to populated areas along the coast. Our research focused on identifying the critical hotspots that witnessed such compound hazards and how they are impacted by global warming. The results identify the critical areas based on the higher dependence between extreme wind and precipitation events and the increased frequency of occurrences. Robust and proactive measures are needed for these hotspot regions to minimize the risk from compound events under climate change. Key Points: Precipitation extremes showed a significant increase in magnitude compared to wind extremes in coastal regions globallyHigher dependence between extreme wind and precipitation was observed on the Southeast USA, Philippines, China, and North Australia coastsA higher percentage of coastal areas in the North Atlantic, East, and South Asia are likely to see more compound events in the future [ABSTRACT FROM AUTHOR]

This article discusses climate change and hurricanes. Papers that appeared in the scholarly journals "Nature" and "Science" during the summer of 2005 raised the question of global warming being the cause of the record-breaking hurricane season of 2005. The article examines that argument, noting that many scientists believe that human-induced climate warming is indeed real. Also discussed is the increasing intensity of hurricanes since 1975, as well as the rise in seas surface temperatures and greenhouse gases in the atmosphere.

Coral reefs throughout the world are under severe challenges from many environmental factors. This paper quantifies the size structure of populations and the growth rates of corals from 2000 to 2008 to test whether the Discovery Bay coral colonies showed resilience in the face of multiple acute stressors of hurricanes and bleaching. There was a reduction in numbers of colonies in the smallest size class for all the species at all the sites in 2006, after the mass bleaching of 2005, with subsequent increases for all species at all sites in 2007 and 2008. Radial growth rates (mm yr¿1) of non-branching corals and linear extension rates (mm yr¿1) of branching corals calculated on an annual basis from 2000¿2008 showed few significant differences either spatially or temporally. At Dairy Bull reef, live coral cover increased from 13±5% in 2006 to 20±9% in 2007 and 31±7% in 2008, while live Acropora species increased from 2±2% in 2006 to 10±4% in 2007 and 22±7% in 2008. These studies indicate good levels of coral resilience on the fringing reefs around Discovery Bay in Jamaica. [Copyright &y& Elsevier]

The article discusses the comments to the published paper "Hurricanes and Global Warming— Potential Linkages and Consequences." The 2005 North Atlantic hurricane season experienced the largest number of named storms, hurricanes, and the only year with three category five storms on record including the most intense Wilma, Rita in the Gulf of Mexico, and the most costly storm Katrina. The relationships between tropical cyclones and global climate change are the subject of many science studies and researches. The science and social complexity of this together with the effects and causes in society are discussed.

Focuses on the impact of global warming. Information on the weather in the 21st century forecasted by Gerald Mehl, a senior scientist at the U.S. National Center for Atmospheric Research; Assertion of researcher Thomas R. Knutson regarding the occurrence of hurricanes; Correlation of global warming and convective storms; Remarks from David J. Karoly, a professor at the University of Oklahoma School of Meteorology, on climatic changes.

Tropical cyclones (TCs) undergoing strong extratropical transition (ET) can produce adverse societal impacts in areas that rarely experience direct TC impacts. This, in conjunction with projected environmental changes in climatological ET regions, motivates the investigation of possible future changes in ET characteristics. We utilize a small ensemble of numerical model simulations to examine how warming affects the ET of Hurricane Irene. To assess the effects of climate change, we use the pseudo-global warming method in which thermodynamic changes, derived from an ensemble of 20 CMIP5 GCMs, are applied to analyzed initial and lateral boundary conditions of model simulations. We find increased storm intensity in the future simulations, both in reduced minimum sea level pressure and strengthened 10-m wind speed. Storm-centered composites indicate a strengthening of tropospheric potential vorticity near the center of Irene, consistent with enhanced latent heat release. The results also demonstrate that Irene's precipitation in the warmed simulations increases at a rate that exceeds Clausius–Clapeyron scaling, owing to enhanced moisture flux convergence and an additional contribution from increased surface evaporation. The duration of the transition process increased in the warmed simulations due to a weakened midtropospheric trough and reduced vertical wind shear and meridional SST gradient with a slower northward translation. These results suggest that transitioning storms may exhibit an increased ability to extend TC-like conditions poleward, and motivates additional research. [ABSTRACT FROM AUTHOR]

Tropical cyclones have enormous costs to society through both loss of life and damage to infrastructure. There is good reason to believe that such storms will change in the future as a result of changes in the global climate system and that such changes may have important socioeconomic implications. Here a high-resolution regional climate modeling experiment is presented using the Weather Research and Forecasting (WRF) Model to investigate possible changes in tropical cyclones. These simulations were performed for the period 2001-13 using the ERA-Interim product for the boundary conditions, thus enabling a direct comparison between modeled and observed cyclone characteristics. The WRF simulation reproduced 30 of the 32 named storms that entered the model domain during this period. The model simulates the tropical cyclone tracks, storm radii, and translation speeds well, but the maximum wind speeds simulated were less than observed and the minimum central pressures were too large. This experiment is then repeated after imposing a future climate signal by adding changes in temperature, humidity, pressure, and wind speeds derived from phase 5 of the Coupled Model Intercomparison Project (CMIP5). In the current climate, 22 tracks were well simulated with little changes in future track locations. These simulations produced tropical cyclones with faster maximum winds, slower storm translation speeds, lower central pressures, and higher precipitation rates. Importantly, while these signals were statistically significant averaged across all 22 storms studied, changes varied substantially between individual storms. This illustrates the importance of using a large ensemble of storms to understand mean changes. [ABSTRACT FROM AUTHOR]

In this article, the author focuses on the 2017 Atlantic hurricane season. Topics discussed include findings of a study concerning the rising hazard of storm-surge flooding following hurricanes like Harvey, Irma, and Maria; ways which affects global warming; and importance of factors unrelated to modern climate change.

An Anthropogenic Climate Change Index (ACCI) is developed and used to investigate the potential global warming contribution to current tropical cyclone activity. The ACCI is defined as the difference between the means of ensembles of climate simulations with and without anthropogenic gases and aerosols. This index indicates that the bulk of the current anthropogenic warming has occurred in the past four decades, which enables improved confidence in assessing hurricane changes as it removes many of the data issues from previous eras. We find no anthropogenic signal in annual global tropical cyclone or hurricane frequencies. But a strong signal is found in proportions of both weaker and stronger hurricanes: the proportion of Category 4 and 5 hurricanes has increased at a rate of ~25-30 % per °C of global warming after accounting for analysis and observing system changes. This has been balanced by a similar decrease in Category 1 and 2 hurricane proportions, leading to development of a distinctly bimodal intensity distribution, with the secondary maximum at Category 4 hurricanes. This global signal is reproduced in all ocean basins. The observed increase in Category 4-5 hurricanes may not continue at the same rate with future global warming. The analysis suggests that following an initial climate increase in intense hurricane proportions a saturation level will be reached beyond which any further global warming will have little effect. [ABSTRACT FROM AUTHOR]

Knowledge about factors that are important in coral reef growth help us to understand how reef ecosystems react following major anthropogenic and environmental disturbances. In addition, they may help the industry understand how aquarists can improve the health of their corals. I have studied environmental and climate effects on corals on fringing reefs in Jamaica. Radial growth rates (mm/yr) of non-branching corals calculated on an annual basis from 2000–2008 showed few significant differences either spatially or temporally along the north coast, although growth rates tended to be higher on reefs of higher rugosity and lower macroalgal cover. I have also reconstructed recruitment patterns, using growth modelling, for non-branching corals at sites on the north coast of Jamaica near Discovery Bay, and near Kingston Harbour, on the south coast. For all the sites, recruitment of non-branching corals was lowered due to hurricanes or severe storms. For 1560 non-branching corals at sites along the north coast of Jamaica, from Rio Bueno to Pear Tree, there was a significant difference in estimated coral recruitment in years when there were no storms or hurricanes by comparison to years when storms and hurricanes impacted the area. For 347 non-branching corals at sites in the Port Royal Cays on the south coast, there was a significant difference in estimated coral recruitment in years when there were no storms or hurricanes by comparison to years when storms and hurricanes impacted the area. Interestingly, recruitment of Siderastrea siderea on to the side of the ship channel at Rackham's Cay (~100 m from the path taken by large ships) outside Kingston Harbour had been consistent since its construction. These findings have important implications for better understanding the impacts of tropical storms on coral reefs and for aquarists to better maintain coral reef species in artificial environments. [ABSTRACT FROM PUBLISHER]

This study investigates effects of the climate changes on tourism industry which causes environmental problems during the last several decades. The research aims to specify the precautions to reduce or prevent the problem of these effects while also exhibiting the effects of the climate change on the tourism industry. As a result of global warming, the climate change may have several outcomes such as reductions in glaciers and snow cover, the rise in the sea level, storm and hurricanes which causes consequently natural disasters ending up essential changes in the life of the all inhabitants of the earth. It is irresistible that the mass tourism and other specific tourism types such as winter, sailing, golf tourisms which are determined by the climate conditions may not be affected by these climate changes. All countries must take economic, sociologic and ecologic precautions against the outcomes of the climate changes. Moreover, educational programs must be considered so as to inform the public about these issues. The less CO2 releasing and energy consuming equipment's must be produced to be used in the Tourism Industry and immediate and remedial precautions must be taken into consideration especially for the transportation sector and the energy needs of the tourism facilities. Besides, the tourism industry should pay more attention to the waste recycling issue and the local authorities must fulfill their responsibilities. The adequate educations and precautions must be provided to the administrations and personnel in the Tourism Industry. The government inspections in the Tourist facilities should be performed properly and the incentives must be promoted to the successful tourism businesses. [ABSTRACT FROM AUTHOR]

Tropical cyclones (also known as hurricanes and typhoons) are now believed to be an important component of the Earth’s climate system. In particular, by vigorously mixing the upper ocean, they can affect the ocean’s heat uptake, poleward heat transport, and hence global temperatures. Changes in the distribution and frequency of tropical cyclones could therefore become an important element of the climate response to global warming. A potential analogue to modern greenhouse conditions, the climate of the early Pliocene epoch (approximately 5 to 3 million years ago) can provide important clues to this response. Here we describe a positive feedback between hurricanes and the upper-ocean circulation in the tropical Pacific Ocean that may have been essential for maintaining warm, El Niño-like conditions during the early Pliocene. This feedback is based on the ability of hurricanes to warm water parcels that travel towards the Equator at shallow depths and then resurface in the eastern equatorial Pacific as part of the ocean’s wind-driven circulation. In the present climate, very few hurricane tracks intersect the parcel trajectories; consequently, there is little heat exchange between waters at such depths and the surface. More frequent and/or stronger hurricanes in the central Pacific imply greater heating of the parcels, warmer temperatures in the eastern equatorial Pacific, warmer tropics and, in turn, even more hurricanes. Using a downscaling hurricane model, we show dramatic shifts in the tropical cyclone distribution for the early Pliocene that favour this feedback. Further calculations with a coupled climate model support our conclusions. The proposed feedback should be relevant to past equable climates and potentially to contemporary climate change. [ABSTRACT FROM AUTHOR]

A global atmospheric model with roughly 50-km horizontal grid spacing is used to simulate the interannual variability of tropical cyclones using observed sea surface temperatures (SSTs) as the lower boundary condition. The model’s convective parameterization is based on a closure for shallow convection, with much of the deep convection allowed to occur on resolved scales. Four realizations of the period 1981–2005 are generated. The correlation of yearly Atlantic hurricane counts with observations is greater than 0.8 when the model is averaged over the four realizations, supporting the view that the random part of this annual Atlantic hurricane frequency (the part not predictable given the SSTs) is relatively small (<2 hurricanes per year). Correlations with observations are lower in the east, west, and South Pacific (roughly 0.6, 0.5, and 0.3, respectively) and insignificant in the Indian Ocean. The model trends in Northern Hemisphere basin-wide frequency are consistent with the observed trends in the International Best Track Archive for Climate Stewardship (IBTrACS) database. The model generates an upward trend of hurricane frequency in the Atlantic and downward trends in the east and west Pacific over this time frame. The model produces a negative trend in the Southern Hemisphere that is larger than that in the IBTrACS. The same model is used to simulate the response to the SST anomalies generated by coupled models in the World Climate Research Program Coupled Model Intercomparison Project 3 (CMIP3) archive, using the late-twenty-first century in the A1B scenario. Results are presented for SST anomalies computed by averaging over 18 CMIP3 models and from individual realizations from 3 models. A modest reduction of global and Southern Hemisphere tropical cyclone frequency is obtained in each case, but the results in individual Northern Hemisphere basins differ among the models. The vertical shear in the Atlantic Main Development Region (MDR) and the difference between the MDR SST and the tropical mean SST are well correlated with the model’s Atlantic storm frequency, both for interannual variability and for the intermodel spread in global warming projections. [ABSTRACT FROM AUTHOR]

Changes in tropical cyclone activity are among the more potentially consequential results of global climate change, and it is therefore of considerable interest to understand how anthropogenic climate change may affect such storms. Global climate models are currently used to estimate future climate change, but the current generation of models lacks the horizontal resolution necessary to resolve the intense inner core of tropical cyclones. Here we review a new technique for inferring tropical cyclone climatology from the output of global models, extend it to predict genesis climatologies (rather than relying on historical climatology), and apply it to current and future climate states simulated by a suite of global models developed in support of the most recent Intergovernmental Panel on Climate Change report. This new technique attacks the horizontal resolution problem by using a specialized, coupled ocean-atmosphere hurricane model phrased in angular momentum coordinates, which provide a high resolution of the core at low cost. This model is run along each of 2,000 storm tracks generated using an advection-and-beta model, which is, in turn, driven by large-scale winds derived from the global models. In an extension to this method, tracks are initiated by randomly seeding large areas of the tropics with weak vortices and then allowing the intensity model to determine their survival, based on large-scale environmental conditions. We show that this method is largely successful in reproducing the observed seasonal cycle and interannual variability of tropical cyclones in the present climate, and that it is more modestly successful in simulating their spatial distribution. When applied to simulations of global climate with double the present concentration of carbon dioxide, this method predicts substantial changes and geographic shifts in tropical cyclone activity, but with much variation among the global climate models used. Basinwide power dissipation and storm intensity generally increase with global warming, but the results vary from model to model and from basin to basin. Storm frequency decreases in the Southern Hemisphere and north Indian Ocean, increases in the western North Pacific, and is indeterminate elsewhere. We demonstrate that in these simulations, the change in tropical cyclone activity is greatly influenced by the increasing difference between the moist entropy of the boundary layer and that of the middle troposphere as the climate warms. [ABSTRACT FROM AUTHOR]