A team of social scientists and economists from Colorado and California recently completed a study on the United States economy’s sensitivity to weather variability: extreme heat, extreme cold, droughts, and floods. This study marked the first time that US economic susceptibility to extreme weather had been explicitly quantified.

Seventy years of atmospheric data were used in conjunction with financial data from eleven nongovernmental sectors of the US economy: 1) agriculture, 2) communications, 3) construction, 4) manufacturing, 5) mining, 6) retail trade, 7) services, 8.) transportation, 9) utilities, 10) wholesale trade, and 11) finance, insurance, and real estate.

Figure 1: Deer graze near a flooded oil derrick in a field in Louisiana. Image reproduced from AP.

Mining was found to exhibit the greatest economic sensitivity to extreme weather, which makes sense given that oil, coal, and gas extraction is highly sensitive to price fluctuations from consumers due to weather variability. As expected, agriculture was also found to exhibit high economic sensitivity to extreme weather (second only to mining). However, since agriculture makes up less than 1.5% of the US gross domestic product (GDP), its absolute effect is relatively small.

Overall, variation in total precipitation (i.e. floods, droughts) had a larger effect on gross domestic product by state (GSP) than did temperature fluctuations. New York was found to be the most sensitive state, exhibiting an economic sensitivity of up to 13.5% of their GSP during extreme weather events over the course of the seventy years of this study. Tennessee was found to be the least sensitive, with a maximum 2.5% variability in GSP due to extreme weather. As seen in Figure 2, however, no part of the country generally appears to be more economically sensitive than any other part. The authors mention that this was slightly surprising; for example, one might expect coastal Atlantic states to show a slightly higher sensitivity given the recurring impact of tropical storms and hurricanes on those areas.

Figure 2: State economic sensitivity to extreme weather events as a percentage of total GSP. Image reproduced from Lazo et al.

As a whole, the US was shown to have an economic sensitivity of up to just 3.4% of their GDP, a much lower percentage than most of the states on their own. This illustrates the important fact that nationwide economic production can be adaptive in times of extreme weather and temporarily shift to different locales, thereby mitigating a sharp decrease in national production.

Still, of the US GDP ($14.4 trillion at 2008 dollar levels), this 3.4% still accounts for up to $485.2 billion of economic loss due to extreme weather events. The authors of this study suggest that some of the principle ways that some of this loss could be avoided is by investing in production methods such as better insulation of factory roofs, better drainage systems along key transportation routes, and more weather resistant crops.

The continued improvement of forecasting methods will also decrease the US economic sensitivity to extreme weather. However, they also point out that even with perfect forecasts, it is highly unlikely that all sensitivity can be mitigated. Regardless, with $485.2 billion in potential impacts at 2008 levels, the authors assert that it should be obvious this is still no small matter.

Reference

Lazo, J.K., M. Lawson, P. Larsen, and D. Waldman, 2011: U.S. Economic Sensitivity to Weather Variability. Bull. Amer. Meteor. Soc., 92, 709-720.

by Aura Lawson

La Niña has persisted longer than expected this year, and with it comes agricultural uncertainty for many countries across the globe. Rwanda is no exception.

Anthony Twahirwa, head of Rwanda’s Meteorological Center, explains that their forecasting agency expected decreased rainfall as a result of La Niña, or abnormally cool waters in the eastern Pacific, but that they didn’t expect the pattern to persist for as long as it has.

Map of Rwanda. Image reproduced from HistorySpeaks.org.uk

“Normally, the country should have started receiving rains at a regular interval from March this year but we are still waiting for it to start,” explains Twahirwa. With this same pattern happening several years in a row, the problem has been exacerbated and it is expected that the Rwandan government will soon have to start tapping into its emergency food stores.

A big dilemma for Rwandan farmers has been whether or not to plant seeds at all this year. If seeds are not planted, it is certain that there will be no food come harvest time at the end of the summer. Conversely, if seeds are indeed planted, there is a high chance of there not being sufficient moisture for the seeds to germinate this year, and a significant amount of money will have been lost in the planting that could have been avoided. Under either scenario, this year’s harvest will be ruined and the country will have to adopt widespread drought mitigation strategies.

This lack of rainfall comes at a time when temperatures are higher than ever in Rwanda. The last decade was the warmest on record, with 2010 being the hottest year on record. Average maximum temperatures were nearly three degrees warmer between 2001 and 2010 than they were from 1990 to 2000.

Stunted crops in neighboring Tanzania, which has likewise been experiencing record heat and anomalous drought. Image reproduced from Michigan State University.

There are several ways that this scenario could play out in the future. The world could cooperate and find efficient ways to slow global warming by decreasing carbon and methane emissions, preventing further global warming that might contribute to worse droughts. Climate forecasting could get better, which would allow forecasters at Rwanda’s Meteorological Center and across the globe to be prepared for prolonged La Niñas and decreased rains, increasing the chance that farmers, the agricultural sector, and the country’s emergency management service will be better prepared for such a disaster. Or, nothing happens: the world will be unable to agree upon measures to prevent further climate change; accurate climate forecasting will be nearly impossible due to drastic increases in greenhouse gases without precedent; and humanity will plow ever forward toward a potentially disastrous future.

For now, Rwandans will continue to pray for rain, and meteorologists and climatologists will continue to collect weather data to improve forecasts for the region. Forecasts will better empower the peoples of Rwanda to plan for dry times.

References

Agutamba, Kenneth. “Rwanda: Experts Predict Long Droughts, Call to Increase Food Storage.” AllAfrica. 9 April 2012. 23 April 2012.  <http://allafrica.com/stories/201204090542.html>

National Oceanic and Atmospheric Administration. “NOAA’s El Niño Page.” NOAA. 23 April 2012. <http://www.elnino.noaa.gov/>

F. Sherwood Rowland, one of the world’s greatest environmental heroes, passed away last weekend at the age of 84. Rowland worked in the Physical Sciences Department at the University of California, Irvine, and was the first person to sound the alarm over the damaging effects of chlorofluorocarbons (CFCs) on the ozone layer.

F. Sherwood Rowland

In 1985, scientists studying the Earth’s stratosphere (the second closest atmospheric layer to the surface) realized that there was an unexpected absence of ozone over Antarctica, and that this hole in the ozone layer was increasing in size every year. Furthermore, they were baffled by the cause of its depletion. Ozone, or triatomic oxygen (O3), is of vital importance in our atmosphere because it prevents excess harmful ultraviolet radiation from reaching the Earth’s surface.

Rowland and postdoctoral student Mario Molina were able to show that CFCs, a chemical compound used in many aerosol sprays at the time, were interacting with and destroying ozone particles once the CFCs reached the stratosphere. It was a discovery that was challenged at first because of the previous notion that CFCs were inert and harmless, but it was quickly proven valid and eventually become a discovery that won Rowland a Nobel Prize in 1995.

When it was proven that CFCs were the main culprit of ozone depletion, the wheels went into action at once. The Montreal Protocol of 1987 halted the worldwide production of CFCs and enforced a series of CFC bans in every country in the world. The final ban went into effect in 2010 in third-world countries. The ozone layer has subsequently stopped shrinking, and is now well on its way to recovering.

Change in total global ozone from the 1964-1980 average. Image reproduced from SUNY Suffolk.

Mental Floss magazine describes how “saving the ozone was literally the first thing the whole world ever agreed on.” Much can be learned from this unified worldwide collaboration to protect our delicate planet. In his last decade of work after receiving the Nobel Prize, Rowland went on to seek similar unified support for the stemming of global warming. At a White House climate change summit in 1997, he asked, “Isn’t it a responsibility of scientists, if you believe that you have found something that can affect the environment, isn’t it your responsibility to do something about it, enough so that action actually takes place?”

“If not us, who? If not now, when?”

Thus far it seems that it will take more than simple science to convince world leaders and fossil fuel proponents that humans are contributing to climate change and that something must be done, lest we commit damage that, this time around, cannot be undone.

References

“Ozone layer scientist who ‘saved the world’ dies.” The Guardian 12 Mar. 2012. Environment. 14 Mar. 2012 <http://www.guardian.co.uk/environment/2012/mar/12/ozone-layer-scientist-dies>

“What ever happened to the hole in the ozone layer?” Mental Floss. Jan. 2012: 45.

We are only about two months into 2012, but already the United States has had 183 confirmed tornados and 49 associated fatalities as of March 7. With the debate about global warming and its consequences at the forefront of the nation’s attention, the public likely has many weather-related questions. What is to blame for the apparent increase in severe weather? Is the number of confirmed tornados this far into 2012 abnormal? Could global warming be causing an increase in tornadic activity?

Figure 1: Annual Running Total of Reported Tornados in the U.S. from 2005 through 2012. Image reproduced from SPC.

It is true that we have seen an unusually high number of tornados so far this year. In fact, since the Storm Prediction Center (SPC) in Norman, Oklahoma began charting the annual running total of U.S. tornados in 2005, only 2008 surpasses this year in total number of reported tornados through March 7 (see Figure 1). On a longer timescale, tornado reports have been increasing since 1950, with the greatest increase coming in the last two decades. Climate change advocates might be tempted to attribute this statistic to global warming, while skeptics could attribute this to pure chance.

The two biggest reasons for this rise over the past several decades, however, are not as contentious as it may initially seem – the increase is primarily due to population growth and improved communication technology.

Figure 2: Annual Number of Tornados Reported to the Goodland, Kansas NWS from 1950 to 2010. Image reproduced from NWS.

With more people living in broader areas across tornado-prone regions, fewer tornados have gone unnoticed, especially across the previously sparsely-populated Great Plains (see Figure 2). Additionally, as National Weather Service (NWS) offices and their outreach programs expanded in the 1990s, they had the ability to train more spotters and educate more individuals about how to report tornados. With the advent of the Internet, this process became even easier. Now, adding digital cameras, camcorders, and most recently smartphones into the mix has resulted in hardly a single tornado going unreported.

When a tornado is reported, however, it does not necessarily mean that a tornado actually occurred. While preliminary reports issued by the SPC include every tornado that was reported to each NWS office, often these reports will be from the same storm or from a non-trained spotter who mistook a microburst or strong gust front for a tornado. Only after trained meteorologists and engineers examine the damage site and classify it as tornadic does the tornado go from being ‘reported’ to ‘confirmed’. It is at this point that the tornado is given a damage rating on the Enhanced Fujita Scale, ranging from EF-0 (least damaging) to EF-5 (most damaging). Approximately 85% of reported tornados result in becoming confirmed tornados.

Population increase, better communication, and an unrepresentatively high initial number of reported tornados all factor in to this observed increase in tornadic activity over time. But where do the the contributions of these effects stop and the contribution of climate change begin when examining the increasing frequency and possibly strength of tornados?

Figure 3: Months of Peak Tornado Occurrence by State from 1950 to 1991. Image reproduced from the National Severe Storms Laboratory (NSSL).

With an observed increase in global surface temperature, it is not difficult to imagine that there would be more evaporation, more storm formation and precipitation, and thus more tornados. Unfortunately, this is a tough physical connection to make when trying to model changes in severe weather under a warmer climate. Tornados and severe storms are incredibly intricate, erratic, and short-lived events, and hence trying to ascertain their response (in frequency, intensity, and path) to global climate change has thus far been like throwing a rock into Niagara Falls and trying to see its splash. The response of tropical storm and hurricane activity under a warmer climate is slightly better understood since they are longer-lived and more predictable in the short-term, but the current questions still far outnumber the existing answers in this area as well.

The key point to take home is that while extreme weather events may seem to be becoming more prevalent and destructive every year, one must keep in mind every factor that influences our perception of such events. There is little doubt that a changing climate will result in changing frequency and strength of severe weather. But in order to properly understand and be prepared for how these events will continue to change in the future, we must be able to approach the science with as rational and unbiased a mindset as possible.

References

http://www.spc.noaa.gov/wcm/

http://www.crh.noaa.gov/gld/

http://www.nssl.noaa.gov/edu/safety/

Review of Pew Charitable Trust Reports: Climate Change 101

http://www.pewclimate.org/global-warming-basics/climate_change_101?utm_source=Pew+Center+on+Global+Climate+Change+newsletter+list&utm_campaign=9e30f90c8b-Pew_Center_February_2011_newsletter&utm_medium=email

By Sara Avrams

Climate Change 101 is a series of 10 brief reports on aspects of the threats posed by global climate change. Although each of the 10 chapters stands on its own merits, and can be downloaded individually, I recommend downloading the whole document. The reader will find it a gripping read. Each chapter has an overview that neatly and clearly gives the reader a taste of what is to come. The forecasts are fast, furious and brutally honest.

Science and Impacts gives a gripping view of the effects of climate change from the scientist’s point of view. The science is easy to understand. Impacts are made in layman’s English with graphic aids, such as pictures, charts and graphs.

Adaptations logically explains how we may need to adapt as our world changes around us. This chapter addresses planning from a number of perspectives ranging from personal to global. The focus is positive and proactive.

Clearly, we got ourselves into this dilemma and we must get ourselves out of it. Technology and cooperation are the keys. Technological Solutions discusses the hardware of many available solutions; laying out those choices with beautiful clarity and simplicity.

The next several chapters: Business Solutions, International Action, Federal Action, State Action, and Local Action focus on the cooperative and governmental issues necessary to address the resolution and remediation of global climate change. These chapters focus on a very complex set of facts and information in a way that is easy to grasp.

I have only two criticisms of these reports. In one case, a comment was made that Texas emits twice the amount of GHGs as Spain. I immediately wondered, “How large is Texas compared to Spain?” (I looked it up. Texas is 269,000 sq. miles with a population of 25 million where Spain is 195,000 sq. miles with a population 45 million.) This comparison would have made for an interesting discussion.

Another comment was made that the earth’s temperature was rising by 1.5 degrees. It would be helpful to explain how this number would affect the earth.

In summary, this is a fascinating booklet on global climate change suited for the general population. A good read for anyone interested in understanding facts and hearing the story told from a positive hopeful perspective.

Frost Byte, Volume 5, Issue 4

Posted on January 29, 2008 by rgbrocs

Last week Allaina attended the AMS/ASLI annual conference in New Orleans. As you might imagine, much of the AMS talk was about hurricanes. The ASLI conference was not so focused on the weather but more about the data about the weather and the role of libraries and data centers in managing and disseminating the data. The usual suspects were in attendance, librarians and data managers from Alaska, UCAR, NOAA, NASA, and other government associations and universities.

The Wednesday keynote address was “Divine Wind: the History and Science of Hurricanes” by Kerry Emmanuel. It was standing room only for his talk, which focused on historical aspects of hurricanes and also a bit of data collection. On Thursday, Allaina was part of a six person panel discussion titled “Discovery, Access, Preservation: Libraries’ Roles in Data Services.” It may have been more appropriate for a USO representative to have been a speaker, but given the 7 minute speaking time, there wasn’t much time to say all that we do at NSIDC.

In the Exhibit Hall, Allaina and Florence met Dr. Richard Crouthamel retired from NOAA and now executive director of the non-profit International Environmental Data Rescue Organization (IEDRO). He was wearing a t-shirt made by his granddaughter that said “Eat. Sleep. Rescue data.” Unfortunately, he didn’t have any for sale. IEDRO’s mission is to assist the scientific and educational communities by: locating and rescuing weather and other environmental data stored on perishable media; digitizing historical environmental data; ensuring the digitized data is available for operational and research applications to its host country as well as the international community of scientists.

Richard (Armstrong) and Allaina have been in contact with Dr. Crouthamel regarding a collection of about 1,000 historic glacier photographs. The collection of glass plates is currently stored at The Regional Museum in Maggiorino Borgatello, Puntas Arenas, Chile. He is attempting to negotiate the transfer of these images to NSIDC.

There are a couple of BAMS meeting issues, as well as IEDRO newsletters, in the library for anyone who might be interested.

Source

http://rgbrocs.wordpress.com/2008/01/29/frost-byte-volume-5-issue-4/

European Science Foundation European Cooperation in Science and Technology High-Level Research Conference

13-17 December 2010

Selwyn College, Cambridge, United Kingdom

Understanding the frequency and magnitude of extreme environmental events and their impacts is a critical aspect of climate prediction. This conference aims to bring together an inter-disciplinary group including statisticians, climate modellers, meteorologists, and other environmental scientists to focus on extreme events and the uncertainties inherent in their understanding.

To learn more visit:

http://www.esf.org/index.php?id=7048