Research Results
Storms in the Future: Changes in Intensity, Cloudiness, Rainfall and Economic Costs
Title | Introduction | Methods | Results 1 | Results 2 | Results 3 | Discussion
Discussion
There appears to be some connection between global warming, storm and cloud properties and the damages caused by storms, but the exact nature of this connection has yet to be discovered. The investigations described above indicate that as global warming continues there will be fewer storms over the northern midlatitudes, and over the United States (particularly in the central part of the country). There will probably be a northward shift of the storm tracks off the east coast of the United States and over the North Atlantic. One would assume that fewer storms should result in less storm related damage.
Trends in insurance records for the past 30 years indicate that this is not the case. In spite of there being fewer storms over the United States during this period, the amount of damages due to midlatitudes storms (adjusted for inflation and prosperity) has increased approximately 5 times. One possible explanation for this discrepancy is that the storms of years with higher damages occur over more urbanized areas, and thus were able to inflict more damages. This was found to be true for one case, and needs to be investigated in greater depth. Another possibility is there is a greater base of insured population in the last decade than in previous decades. The number of people insured and the total value of their policies for each year of this period still need to be assessed.
One investigative team did see a suggestion that the number of storms over the United States has been increasing over the past ten years, and that these storms are intensifying in their strengths compared to previous decades. This is contrary to the thirty-year trend for both these characteristics, and contrary to the findings for the entire northern midlatitudes. The techniques used to determine the trends over the midlatitudes need to be applied to just the United States region to see if these suggested trends over the United States can be verified. If storms over the United States are increasing in strength and frequency, there would be a direct impact upon the damages they produce.
There is some indication that the general cloud properties of the clouds over the United States have been changing from the 80s to the 90s. The average cloud is becoming more optically thick and higher in the atmosphere, indicative of an ability to hold more water. Even if the storms are decreasing in number, the clouds associated with these storms seem to be holding more water and therefore be able to cause more damages. A limited investigation of individual storms indicated that the water carrying ability of the clouds of those storms depends more upon the relative humidity and the temperature of the air where the storms form rather than the actual strength of the storm. In a future of continued global warming, the higher humidity and temperatures may produce clouds with more water content than are currently produced. This will have a direct impact upon the damages that storms of the future may cause.
These connections are at best tenuous at this time. Many more storms from years of high damages and years of low damages needed to be analyzed to see if there are significant differences in the locations of storm formation, the properties of the clouds formed by these storms, and the storm tracks of these storms. Once more storms have been examined, the connections between these factors, global warming and storm damage may become clear. These connections must be made clear because global warming is continuing, and the climate is changing. In order for policy makers to make decisions as to how best to prepare for these future changes, the relationship between these factors must be understood.
Title | Introduction | Methods | Results 1 | Results 2 | Results 3 | Discussion
