Summary. Man-made greenhouse gases are increasing the worldwide long-term average temperature, leading to increasingly more numerous and more damaging extreme weather events. In the U. S.
Introduction. Worldwide long-term average temperatures have been increasing since the industrial revolution began, becoming more pronounced since the middle of the 20th century. This warming is correlated with humanity’s ever-increasing use of fossil fuels for energy, resulting in atmospheric emissions of greenhouse gases. The Fourth Assessment Report (4AR) of the U. N. Intergovernmental Panel for Climate Change (IPCC; a worldwide consortium of several thousand climate scientists) points out that human-caused emissions of greenhouse gases including carbon dioxide since the Industrial Revolution began have resulted in warming of the global average temperature.
For example in the Northern Hemisphere the temperature has risen by more than 1ºF (more than 0.6ºC). 4AR concludes that the warming over the last 50 years (before the report date of 2007) has been caused by the heat-trapping accumulation of greenhouse gases originating from human activities, with a certainty of more than 90%. The concentration of carbon dioxide in the atmosphere is now higher than it has been for the last 700,000 years.
Climate change has wide-ranging effects on the American economy. Among economic sectors that can be affected by variations in climate are energy, agriculture, transportation, insurance, manufacturing, health care, and tourism. According to the National Oceanographic and Atmospheric Administration (NOAA; accessed Aug. 16, 2011), one estimate places one-third of the U.S. gross domestic product in sectors affected by climate, or about US$4 trillion (2008 dollars). Another estimate of potential impacts of climate change on the economy, based on detailed analysis of 24 years of data, suggests that economic output can vary by 3.4%, or US$260 billion (2000 dollars).
This post details nationwide estimates in the U. S. U. S.
The objective here is to present a broad estimate of overall costs to the U. S.
Forests: Wildfires.
Fighting wildfires incurs considerable direct suppression costs. Once a fire is extinguished, further direct, indirect and societal losses continue to accumulate. These include suppression costs, property damage costs, public health factors, vegetation losses and loss of wildlife habitat, damage to wildlife, water losses including degradation of water quality, air and atmospheric effects, soil erosion and loss of productivity, and recreation and esthetics losses. When all these factors are included, the total may reach as high as 10 to 30 times the direct cost of the suppression effort.
For wildfires in the U. S.
Source : National Climatic Data Center Aug. 16, 2011 .
In spite of the pronounced variation from year to year, it is seen that the number of wildfires increases slightly over this time period, and that the acres burned shows a clearly increasing trend beyond 2000.
Economic and human costs for wildfires from 2000 to 2010 are given by NOAA in the following table:
Year | Fatalities | Injuries | Property Damage (US$ million ) | Crop Damage (US$ million ) | Total Damage (US$ million ) |
2000 | 3 | 100 | $2,678.7 | $9.0 | $2,687.7 |
2001 | 5 | 46 | $56.5 | $0.0 | $56.5 |
2002 | 1 | 138 | $251.0 | $2.5 | $253.5 |
2003 | 0 | 2 | $2,797.9 | $0.0 | $2,797.9 |
2004 | 0 | 0 | $19.8 | $0.0 | $19.8 |
2005 | 0 | 0 | $46.0 | $0.0 | $46.0 |
2006 | 0 | 0 | $211.6 | $0.0 | $211.6 |
2007 | 19 | 225 | $1,466.1 | $46.7 | $1,512.8 |
2008 | 3 | 35 | $246.1 | $2.1 | $248.2 |
2009 | 2 | 109 | $114.1 | $1.4 | $115.6 |
2010 | 1 | 24 | $244.9 | $1.9 | $246.8 |
Source: NOAA, http://www.economics.noaa.gov/?goal=climate&file=events/fire ; Accessed Aug. 16, 2011 .
The damage estimates in the table above may be too low. An itemization [1] linked from the table above of seasons with over US$1 billion in costs gives several cases in some years with much higher costs, three of which are:
- 2009: Western wildfires, more than 5.9 million acres and 200 structures in
California - 2008: Wildfires, more than 5.2 million acres and over 1,000 structures in
California - 2006, Wildfires, almost 10 million acres, over US$1 billion in costs.
The President’s proposed budget for Fiscal Year 2011 included US$2.37 billion for Wildland Fire Management and Reserve Fund. The budget proposal recognizes “Many of the most urgent forest … problems of the past 20 years— wildfires,… and expanding forest insect infestations [see below] — have been driven, in part, by changing climate; future impacts are projected to be even more severe.”
Forests: Pine Bark Beetles. Pine bark beetles destroy western pines by producing larvae that consume the living layer of the tree under the bark. Their viability is closely temperature dependent. Warmer temperatures that result from man-made global warming enhance viability of larvae over winters, and drought weakens the resistance of host trees (Raffa and coworkers, BioScience 2008 Vol. 58, pp.501-517). Williams and coworkers (Proc. Natl. Acad. Sci., 2010, Vol. 107 pp. 21289–21294) assessed local forest growth year-by-year at 1,097 locations in the U. S. They estimate that up to 18% of southwestern forests died or were lost from 1997 to 2008, about three-fourths to bark beetle infestations and the remainder to fires.
Bentz and coworkers (BioScience 2010 Vol. 60:602-613) report, based on models of future warming in the habitat of the affected pine species, that in the coming century warmer temperatures will lead to new destruction of forests at higher elevations and more northern latitudes, regions from which the beetles are currently excluded because of their temperature sensitivity. According to Thomas Schueneman, in Colorado Wyoming
The Western Forestry Leadership Coalition (WFLC) (report dated March 8, 2007 ; accessed Aug. 14, 2011 ) notes that mountain pine beetles are indigenous, but that destruction of pine forests by them has increased drastically in recent years, up to the most recent data for 2005, as shown below:
Source: Western Forestry Leadership Coalition http://www.wflccenter.org/news_pdf/222_pdf.pdf
The graphic shows that as many as 10 million acres were destroyed in 2003.
The WFLC points out that human activities producing climate change aggravate bark beetle destruction of pine forests. Detrimental effects include worsening risk of wildfires from killed trees, depletion of killed trees from those actively removing the greenhouse gas carbon dioxide from the air, and negative impacts on economic activity due to lost recreational appeal of killed forests. The wildfire effect positively reinforces further beetle infestations since trees previously exposed to fire become more susceptible to beetles.
Further economic costs arise from attempted management of beetle activity. These include thinning of susceptible forest stands and replanting lost pine stands with new seedlings.
Drought
NOAA (accessed Aug. 16, 2011 ) identifies agriculture, water resources, tourism and ecosystems as being strongly affected by the occurrence of drought. As long ago as 1995, the Federal Emergency Management Agency estimated annual effects of drought at US$6-8 billion (presumably 1995 dollars). NOAA points out that occurrence and effects of drought are likely to worsen in future years, since models for global warming indicate more numerous and severe heat waves in forest regions in coming decades. This makes drought and conditions conducive to forest wildfires more likely.
Direct damage from drought from 2000 to 2010 is shown in the table below.
Year | Property Damage (US$, million) | Crop Damage (US$, million) |
2000 | $0.9 | $3,096.4 |
2001 | $0.0 | $1,592.4 |
2002 | $0.0 | $922.0 |
2003 | $774.2 | $687.0 |
2004 | $0.0 | $1.4 |
2005 | $87.5 | $1,481.5 |
2006 | $151.8 | $2,747.9 |
2007 | $3.7 | $1,635.7 |
2008 | $0.1 | $1.7 |
2009 | $0.1 | $51.1 |
2010 | $0.5 | $751.8 |
Source: NOAA, http://www.economics.noaa.gov/?goal=climate&file=events/drought; Accessed Aug. 16, 2011 .
These damage estimates may be low. An itemization [1] linked from the table above of seasons with over US$1 billion in damages and costs gives several cases in the years tabulated above with much higher costs, three of which are:
- 2008, severe drought and heat in the south and west, costs over US$2 billion;
- 2007,
Great Plains and eastern drought, over US$5 billion costs; and - 2006, widespread drought, US$6.2 billion in costs.
The New York Times reported on August 11, 2011 that excessive rainfall in the spring and excessive heat and drought across broad agricultural regions of the U. S. this summer have led to decreased predicted harvest levels for soybeans and other oil seeds, corn, cotton and wheat, compared to 2010. The report is based on the latest monthly reports from the U. S. Department of Agriculture on crop production and world agricultural supply and demand estimates. Spring rains flooded fields in certain regions delaying or completely preventing sowing, and excessive heat and drought this summer have affected growth and ripening. Predicted harvests as well as yields per acre are lower than last year.
These constrained supplies are expected to lead to higher prices. Prices for meat, whose production depends on feed grains, likewise are predicted to increase. Additionally livestock is being slaughtered earlier than normal, with lower body weights, due to drought. According to indexmundi.com, as of August 12, 2011 , percent year-to-year price changes for U. S.
Product | July 2010-July 2011 % chg, | Link |
Wheat | 55.2 | |
Corn | 83.5 | |
Soybeans | 35.3 | |
Cotton | 77.4 | |
Commodity Food Price Index | 25.3 |
These increases at the commodity level are expected to lead to price increases for the consumer as well.
River Floods.
River floods present a major and increasing threat of physical damage and societal harm in the U. S.
Flooding of the greater Mississippi River watershed is likely to increase in future decades. Increased human activity has constrained the flow of the river with levees, so that excessive water flow risks exceeding the bounds imposed by them. Global warming models envision more rainfall in the Mississippi River watershed over the next 30 years (written in 2008) than earlier, leading to greater predicted frequency and severity of floods [3]. Precipitation could be 21% greater, and water flow 51% greater, than at present [4].
Brody and coworkers [2] point out that flood damage entails both direct costs and indirect costs. Direct costs describe the immediate physical damage and/or reconstruction costs arising from a flood. Indirect costs originate from more distributed consequences of a flood, and include factors such as lost personal income with resulting decrease in local economic activity, reduction in property values in affected areas, reduced tax receipts by governments at all levels, psychological effects and ecosystem degradation. Indirect costs are much more difficult to assess and frequently are not considered in discussions of damage resulting from a catastrophe. Nevertheless they can be considerably greater than direct cost estimates.
Flooding in the U. S.
Year | Deaths | Injuries | Property Damage (US$, million) | Crop Damage (US$, million) |
2000 | 38 | 47 | $1,594.0 | $862.7 |
2001 | 48 | 277 | $1,525.4 | $53.8 |
2002 | 49 | 88 | $818.8 | $103.1 |
2003 | 86 | 70 | $3,051.7 | $189.7 |
2004 | 82 | 128 | $1,984.6 | $399.4 |
2005 | 43 | 38 | $1,737.6 | $117.8 |
2006 | 76 | 23 | $4,144.5 | $220.1 |
2007 | 87 | 59 | $1,862.0 | $608.1 |
2008 | 82 | 46 | $3,519.1 | $2,265.0 |
2009 | 53 | 26 | $1,077.5 | $39.4 |
2010 | 103 | 310 | $3,927.0 | $1,187.0 |
Source: NOAA, http://www.economics.noaa.gov/?goal=climate&file=events/precip; Accessed Aug. 16, 2011 .
These damage estimates may be low. An itemization [1] linked from the table above of seasons with over US$1 billion in damages and costs includes an estimate for 2008 from agricultural loss and property damage of over US$15 billion.
Brody and coworkers [2], evaluating similar tabulations, conclude that between 1960 and 2008, in spite of considerable year-to-year fluctuations such as shown in the table, the overall trends of property and crop damage increased over the 48 year period examined. Property damage increased 54-fold, from US$51 million in the 1960s to US$2.77 billion in the 2000s.
Estimates for flood damage in the U. S.
Flood damage losses from precipitation-caused flooding 1904-2010. (The $49.7 billion point for 2005, although high, excludes damage from coastal storm surges that year, as do all the data.)
Source for data: U. S. National Oceanic and Atmospheric Administration, National Weather Service; http://www.weather.gov/hic/flood_stats/Flood_loss_time_series.shtml (Page last modified: 2 June, 2011 ; accessed Aug. 15, 2011 .)
Although highly scattered, the trend in inflation-adjusted flood losses increases with time, as does the five-year rolling average. This trend is ascribed by authors such as [3] and [4] to both higher flood water volume and greater placement of damage-susceptible development in flood plains that can be affected if river constraints fail. The nation’s average flood damage is increasing at a rate of 2.9% per year, which is three times faster than the growth rate of the nation’s population [5]. The 30-year average loss covering 1981-2010, calculated by the National Weather Service, is US$7.56 billion per year. The average death rate was 94 per year.
Wuebbles and coworkers model predicted precipitation runoff in the upper Midwest of the U. S. through 2099, using three different scenarios for severity of greenhouse gas-induced worsening of global warming from 4AR [6]. They conclude that the northern part of the Mississippi River watershed will experience more precipitation with higher intensity such that runoff will increase and the risk of flooding will be exacerbated, by the end of this century.
Conclusions
Worldwide, the long-term average temperature has been increasing since the industrial revolution began. The fossil fuels that humans burn for energy to power that revolution produce the carbon dioxide leading to trapping excess heat from solar radiation, which is leads to the temperature increase. Climate scientists project that, in view of the continued and expanding consumption of fossil fuels, warming of the atmosphere will grow more severe as the present century progresses.
Major economic costs associated with extreme weather events in the U. S.
Forest wildfires: loss of millions of acres of forest; as high as US$2.8 billion;Forest wildfires: direct federal budgeted expenditures for suppression, US$2.4 billion;Forest pine beetle infestations: as much as three times the acreage destroyed by wildfires; damage assessment could be several billion dollars.- Drought: crop damage as high as US$3 billion; staple food commodity futures prices today 25% higher than one year ago on average, with effects extending to retail prices for foods using those staples affecting the entire U. S. population;
- River floods: agricultural loss and property damage as high as US$15 billion.
These damage estimates represent major losses to the American economy. While each category had produced damaging events even before global warming became significant, the additional losses arising from the increased frequency and severity of extreme events, and their predicted worsening, are most likely ascribable to the effects of global warming.
Extreme weather events such as those itemized produce their damaging effects episodically, with varying severity, and over shorter or longer time frames. Likewise direct and indirect costs arise over different time frames. These extreme events, since they are unforeseen, usually generate responses that also are unforeseen and may or may not have been budgeted for. In addition, the more intangible deleterious societal impacts from extreme events are not readily quantified.
An alternative approach might be to implement long-term policies that address the causes of global warming, and that result in programs that stimulate long-term economic activity both in the governmental and private corporate realms. This idea will be pursued in a coming post on this blog.
References
[1]. Lott N., Ross, T., Smith, A., Houston, T., and Shein, K., 2011, “Billion Dollar U.S. Weather Disasters, 1980 – 2010”; http://www.ncdc.noaa.gov/img/reports/billion/billionz-2010.pdf Accessed Aug. 16, 2011 .
[2]. “Rising Waters: The Causes and Consequences of Flooding in the United States” Samuel D. Brody, Wesley E. Highfield, Jung Eun Kang, Cambridge University Press, New York 2011 ©2011. Accessed in parts made available at http://books.google.com/books?hl=en&lr=&id=IbRmnGiIFdMC&oi=fnd&pg=PR5&dq=cost+of+damage+and+loss+from+U.+S.+floods&ots=DJOaVgVr5_&sig=iji0QFNSi6BikWc4eawz8vSV5-U#v=onepage&q=cost%20of%20damage%20and%20loss%20from%20U.%20S.%20floods&f=false Aug. 14-16, 2011.
[3]. Kusky, T. in Robert E. Criss and Timothy M. Kusky, 2009, “Finding the Balance between Floods, Flood Protection, and River Navigation”, published by Saint Louis University, Center for Environmental Sciences; pp. 1-8. http://ces.slu.edu/annualreport/FloodForum_Book_final.pdf
[4]. Kusky, T., Lei, Q., Ghulam, A., and Chen, Y. in Robert E. Criss and Timothy M. Kusky, 2009, “Finding the Balance between Floods, Flood Protection, and River Navigation”, published by Saint Louis University, Center for Environmental Sciences; pp. 9-15. http://ces.slu.edu/annualreport/FloodForum_Book_final.pdf
[5]. Fahlund, A., in Robert E. Criss and Timothy M. Kusky, 2009, “Finding the Balance between Floods, Flood Protection, and River Navigation”, published by Saint Louis University, Center for Environmental Sciences; pp. 86-88. http://ces.slu.edu/annualreport/FloodForum_Book_final.pdf
[6]. Wuebbles, D., Hayhoe, K., and Cherkauer, K. in Robert E. Criss and Timothy M. Kusky, 2009, “Finding the Balance between Floods, Flood Protection, and River Navigation”, published by Saint Louis University, Center for Environmental Sciences; pp. 47-54. http://ces.slu.edu/annualreport/FloodForum_Book_final.pdf
© 2011 Henry Auer
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