Thursday, November 29, 2012

Toting up the disaster's costs

As the folks who calculate these things tote up the costs of the billion-dollar weather disasters of 2012, some are reaching a rather astonishing conclusion—that Hurricane Sandy was NOT the most expensive.  That "honor" goes to the great Corn Belt drought.  Hurricanes may be the most spectacular weather events but for wrecking things, nothing beats old-fashioned drought.

Lessons from 2012: Droughts, not Hurricanes, are the Greater Danger

Posted by: Dr. Jeff Masters,  November 16, 2012

The colossal devastation and loss of life wrought by Hurricane Sandy makes the storm one of the greatest disasters in U.S. history. The storm and its aftermath have rightfully dominated the weather headlines this year, and Sandy will undoubtedly be remembered as the most notable global weather event of 2012. But shockingly, Sandy is probably not even the deadliest or most expensive weather disaster this year in the United States--Sandy's damages of perhaps $50 billion will likely be overshadowed by the huge costs of the great drought of 2012. While it will be several months before the costs of America's worst drought since 1954 are known, the 2012 drought is expected to cut America's GDP by 0.5 - 1 percentage points, said Deutsche Bank Securities this week. “If the U.S. were growing at 4 percent, it wouldn’t be as big an issue, but at 2 percent, it’s noticed,” said Joseph LaVorgna, the chief U.S. economist at Deutsche. Since the U.S. GDP is approximately $15 trillion, the drought of 2012 represents a $75 - $150 billion hit to the U.S. economy. This is in the same range as the estimate of $77 billion in costs for the drought, made by Purdue University economist Chris Hurt in August. While Sandy's death toll of 113 in the U.S. is the second highest death toll from a U.S. hurricane since 1972, it is likely to be exceeded by the death toll from the heat waves that accompanied this year's drought. The heat waves associated with the U.S. droughts of 1980 and 1988 had death tolls of 10,000 and 7,500 respectively, according to NOAA's National Climatic Data Center, and the heat wave associated with the $12 billion 2011 Texas drought killed 95 Americans. With July 2012 the hottest month in U.S. history, I expect the final heat death toll in the U.S. this year will be much higher than Sandy's death toll.

Figure 1. The top-ten list of most expensive U.S. weather-related disasters from NOAA's National Climatic Data Center (NCDC) is dominated by hurricanes and droughts. Three of the top five disasters are droughts. The numbers for Hurricane Sandy and the 2012 drought are preliminary numbers from media sources, and are not from NCDC.

Drought: civilization's greatest natural enemy

People fear storms, and spectacular and devastating storms like Hurricane Sandy and Hurricane Katrina have stirred more debate in the U.S. about taking action against climate change than any other weather event. But I argue that this attention is misplaced. Drought is our greatest enemy. Drought impacts the two things we need to live--food and water. The history of civilization is filled with tales of great storms that have killed thousands and caused untold suffering and destruction. But cities impacted by great storms inevitably recover and rebuild, often stronger than before. I expect that New York City, the coast of New Jersey, and other areas battered by Sandy will do likewise. But drought can crash civilizations. Drought experts Justin Sheffield and Eric Wood of Princeton, in their 2011 book, Drought, list more than ten civilizations and cultures that probably collapsed because of drought. Among them: The Mayans of 800 - 1000 AD. The Anasazi culture in the Southwest U.S. in the 11th - 12th centuries. The ancient Akkadian Empire in Mesopotamia. The Chinese Ming Dynasty of 1500 - 1730. When the rains stop and the soil dries up, cities die and civilizations collapse, as people abandon lands no longer able to supply them with the food and water they need to live.

The coming great droughts

We should not assume that the 21st century global civilization is immune from collapse due to drought. If we continue on our current path of ever-increasing emissions of carbon dioxide, the hotter planet that we will create will surely spawn droughts far more intense than any seen in recorded history, severely testing the ability of our highly interconnected global economy to cope. The coming great drought disasters will occur at a time when climate change is simultaneously creating record rainfall and flooding in areas that happen to be in the way of storms. Global warming puts more heat energy into the atmosphere. That means more more water will evaporate from the oceans to create heavier rains and make storms stronger, and there will be more heat energy to increase the intensity of heat waves and droughts. It all depends upon if you happen to lie on the prevailing storm track or not which extreme you'll experience. In the future, if you're not being cooked in a record drought, you're going to be washed away in a record flood. Just ask the residents of the Midwest. In 2011, residents of the Midwest endured the largest floods on record on their three great rivers--the Mississippi, Missouri, and Ohio. In 2012, the same region endured their worst drought since 1954, and a top-ten warmest summer.

The nation's top scientific research group, the National Research Council, released an 18-month study on November 9, 2012, titled, "Climate and Social Stress: Implications for Security Analysis". They stated: “It is prudent to expect that over the course of a decade some climate events--including single events, conjunctions of events occurring simultaneously or in sequence in particular locations, and events affecting globally integrated systems that provide for human well-being--will produce consequences that exceed the capacity of the affected societies or global system to manage and that have global security implications serious enough to compel international response.” In other words, states will fail, millions will suffer famine, mass migrations and war will break out, and national and international agencies will be too overwhelmed to cope. We were very lucky that the 2012 U.S. drought did not occur the year following the great 2010 Russian drought. That drought drove up food prices to the highest levels since 1992, and helped trigger social unrest that led to the "Arab Spring" revolts that overthrew multiple governments. Severe droughts in back-to-back years in major world grain-producing areas could cause unprecedented global famine and unrest, and climate change is steadily increasing the odds of this happening. more
And while drought may be the most expensive, flooding is probably not very far behind.  It turns out that old nemesis may in fact pose the greatest long-term risk to human investment.

US coastal cities in danger as sea levels rise faster than expected, study warns

Satellite measurements show flooding from storms like Sandy will put low-lying population centres at risk sooner than projected
Suzanne Goldenberg, US environment correspondent, 27 November 2012

Sea-level rise is occurring much faster than scientists expected – exposing millions more Americans to the destructive floods produced by future Sandy-like storms, new research suggests.

Satellite measurements over the last two decades found global sea levels rising 60% faster than the computer projections issued only a few years ago by the United Nations' Intergovernmental Panel on Climate Change.

The faster sea-level rise means the authorities will have to take even more ambitious measures to protect low-lying population centres – such as New York City, Los Angeles or Jacksonville, Florida – or risk exposing millions more people to a destructive combination of storm surges on top of sea-level rise, scientists said.

Scientists earlier this year found sea-level rise had already doubled the annual risk of historic flooding across a widespread area of the United States.

The latest research, published on Wednesday in Environmental Research Letters, found global sea-levels rising at a rate of 3.2mm a year, compared to the best estimates by the IPCC of 2mm a year, or 60% faster.

Researchers used satellite data to measure sea-level rise from 1993-2011. Satellites are much more accurate than tide gauges, the study said.

The scientists said they had ruled out other non-climatic causes for the rise in water levels – and that their study demonstrated that researchers had under-estimated the effects of climate change.

"Generally people are coming around to the opinion that this is going to be far worse than the IPCC projections indicate," said Grant Foster, a US-based mathematician who worked on the paper with German climatologist Stefan Rahmstorf.

The implications are serious – especially for coastal areas of the US. Large portions of America's Atlantic and Pacific coasts are regarded as "hotspots" for sea-level rise, with water levels increasing at twice the rate of most other places on the planet.

Scientists previously had expected a global sea-level rise of 1m by the end of the century. "But I would say that if you took a poll among the real experts these days probably they would say that a more realistic figure would be more than that," Foster said.

"The study indicates that this is going to be as bad or worse than the worst case scenarios of the IPCC so whatever you were planning from Cape Hatteras to Cape Cod in terms of how you were preparing for sea-level rise – if you thought you had enough defences in place, you probably need more," Foster said.

A study published last March by Climate Central found sea-level rise due to global warming had already doubled the risk of extreme flood events – so-called once in a century floods – for dozens of locations up and down the Atlantic and Pacific coasts.

It singled out the California cities of Los Angeles and San Diego on the Pacific coast and Jacksonville, Florida, and Savannah, Georgia, on the Atlantic, as the most vulnerable to historic flooding due to sea-level rise. more

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