Windswept_ The Story of Wind and Weather - Marq de Villiers [136]
Ivan didn't batter me into the sea as the gale in Cape Town had threatened to do, or even batter the sea into my house, though it was plenty strong enough. Perhaps as a consequence of the possibilities, I remain wary of wind but would like to get a little of my own back and put this wariness to some use, to harness wind to increase my own comfort and security. In this, I think, I am also Us, in the larger sense of a collectivity and a species. We are badly wounding our air and through it our climate, but we know enough now to be able to bring the system back to health. We know how wind works, and what makes it worse and what doesn't, and how to make it cleaner and less hazardous to our survival. We have also learned how to employ it to generate the energy that our civilization needs. Nature has given us the perpetual motion machine we call wind. We can put it to work to make things better.
APPENDIX 1
The composition of the modern atmosphere
The atmosphere contains gases that are considered to be permanent (which remain essentially constant by percent) and gases considered to be variable (which have changing concentrations over a finite period of time).
APPENDIX 2
APPENDIX 3
The Saffir-Simpson hurricane scale
Category 1:
Sustained winds 74-95 mph (64-82 knots). Storm surge generally 4—5 feet above normal. No real damage to building structures. Damage primarily to unanchored mobile homes, shrubbery, and trees. Some damage to poorly constructed signs. Also, some coastal road flooding and minor pier damage.
Category 2:
Sustained winds of 96-110mph (83-95 knots). Storm surge generally 6-8 feet above normal. Some roofing material, door, and window damage. Considerable damage to shrubbery and trees with some trees blown down. Considerable damage to mobile homes, poorly constructed signs, and piers. Coastal and low-lying escape routes flood 2—4 hours before arrival of the hurricane center. Small craft in unprotected anchorages break moorings.
Category 3:
Sustained winds in-13omph (96-113 knots). Storm surge generally 9-12 feet above normal. Some structural damage to small residences and utility buildings with a minor amount of curtainwall failures. Damage to shrubbery and trees with foliage blown off trees and large trees blown down. Mobile homes and poorly constructed signs are destroyed. Low-lying escape routes cut by rising water 3-5 hours before arrival of the center of the hurricane. Flooding near the coast destroys smaller structures with larger structures damaged by battering from floating debris. Terrain lower than 5 feet above sea level may be flooded inland 8 miles or more. Evacuation of low-lying residences within several blocks of the shoreline may be required.
Category 4:
Sustained winds of 131-155 mph (114-135 knots). Storm surge generally 13-18 feet above normal. More extensive curtainwall failures with some complete roof structure failures on small residences. Shrubs, trees, and all signs blown down. Complete destruction of mobile homes. Extensive damage to doors and windows. Low-lying escape routes may be cut by rising water 3-5 hours before arrival of the center of the hurricane. Major damage to lower floors of structures near the shore. Terrain lower than 10 feet above sea level may be flooded requiring massive evacuation of residential areas as far inland as 6 miles.
Category 5:
Sustained winds greater than 155 mph (135 knots). Storm surge generally greater than 18 feet above normal. Complete roof failure on many residences and industrial buildings. Some complete building failures with small utility buildings blown over or away. All shrubs, trees, and signs blown down. Complete destruction of mobile homes. Severe and extensive window and door damage. Low-lying