The Real Truth About Tornadoes (Op-Ed)

Paul Markowski, Harold Brooks, Yvette Richardson, Robert Trapp, John Allen and Noah Diffenbaugh   |

Twister central: The United States is home to roughly 85 percent of the world's tornadoes, but even by U.S. standards this tornado season has been tragically active. Credit: NOAA View full size image

This open letter was written by six, leading tornado experts from research institutions across the United States. Their brief bios follow below. The authors contributed this article to LiveScience's Expert Voices: Op-Ed & Insights.
Twisters returned to the national spotlight after a Nov. 17 outbreak viciously tore through 12 states, leaving eight people dead.
Research data show that climate change caused by human behavior is fueling more frequent and intense weather, such as extreme precipitation and heat waves — so it's only natural to wonder if this applies to tornadoes, too. Scientists need more data and time to fully address that connection.


That said, some high-profile scientists are misleading the American public about what is, and is not, known about global warming and tornadoes.   [Something Is Rotten at the New York Times (Op-Ed)]
For instance, University of California, Berkeley, professor Richard Muller argued in a recent New York Times opinion piece that "the scientific evidence shows that strong to violent tornadoes have actually been decreasing for the past 58 years, and it is possible that the explanation lies with global warming."
The honest "truth" is that no one knows what effect global warming is having on tornado intensity. Tornado records are not accurate enough to tell whether tornado intensity has changed over time.
Although it is a bit of an exaggeration to say, "backyard dust devils are reported," Muller notes — correctly— that climate change is not responsible for the dramatic rise in annual tornadoes since 1950. Rather, the larger numbers come from improved detection and reporting of weak tornadoes, particularly EF0 tornadoes, where "EF" refers to the enhanced-Fujita scale used by the National Weather Service (NWS).
However, Muller then uses the record of severe tornadoes — those rated EF3 to EF5 and responsible for the most extreme damage and casualties — to reach the following conclusion: "One thing is clear … The number of severe tornadoes has gone down. That is not a scientific hypothesis, but a scientific conclusion based on observation. Regardless of the limitations of climate theory, we can take some comfort in that fact."
His confident claim is based on raw U.S. National Oceanic and Atmospheric Administration (NOAA) records showing an apparent decline in EF3 to EF5 tornado reports in the past 58 years. Unfortunately, it illustrates a lack of understanding of how those reports have been developed, and the changes in the process over time. Scientific conclusions must be based on reliable observations, not just any observations.
Ironically, the reason Muller says one shouldn't attribute the increase in weak (and therefore total) tornado reports to climate change is likely the same reason the intensity of tornadoes has appeared to decline: reporting has not been consistent over the period the tornado records span.
The meteorological community knows very well that early official records systematically rated tornadoes stronger than those in the 1980s and 1990s — that is, tornadoes were awarded higher EF-ratings in those decades than they would have received in more recent times.
Tornadoes occurring prior to the mid-1970s — when the NWS adopted the enhanced Fujita scale — received ratings retrospectively by meteorology students who relied on qualitative damage descriptions in newspaper archives. This effectively "inflated the grades" of those tornadoes because the later ratings came only after considerable in-person scrutiny of the damage, often by engineers who considered not just the damage but also the quality of the construction of damaged structures. The evidence for the overrating of earlier tornadoes includes the fact that environments and damage paths of many strong tornadoes in that retrospective era shared characteristics with weaker tornadoes from later years.
Considerable evidence uncovered in the last decade suggests that previous tornadoes actually were underrated compared to the 1980s and 1990s.
One factor contributing to those ratings was a 2003 policy that required a special team of experts to evaluate the damage of the strongest tornadoes. In an unforeseen consequence, local NWS offices had a tendency to assign lower initial ratings, eliminating the expense and complexity of involving external evaluators. In addition, concerns about construction practices from the engineering community placed additional emphasis on poor construction by damage assessors from the NWS, leading to lower ratings.

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Also, in another complication in assessing long-term tornado intensity trends, the "damage indicators" used to rate tornadoes recently have changed with the adoption of the EF scale, making it dubious to compare tornadoes of the past with those of the present.
Recently, truck-borne Doppler radar observations of tornadoes identified a number of cases in which the radar-measured winds are considerably faster than the official NWS rating implies. For example, the winds measured by these radars in last May's 2.6-mile-wide tornado near El Reno, Okla., topped 280 mph, which would have placed it well into the EF5 range (200+ mph). The official NWS rating based on the available damage indicators, however, was EF3 (136–165 mph).
Finally, Muller's simple analysis of tornado reports does not address possible changes in the seasonality and/or regional nature of tornado occurrence. In fact, the latest climate-model experiments agree that further global warming is likely to increase the likelihood of conditions favorable to the severe thunderstorms that produce tornadoes in the spring and autumn. Although these climate models do not resolve tornadoes, they do predict an increase in the ingredients responsible for past tornadoes.
Paul Markowski, professor of meteorology at Penn State University, was a leader of the recent Second Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX2) and 2013 recipient of the National Weather Association's Fujita Award for his research on tornado formation.
Harold Brooks is a senior research scientist at NOAA's National Severe Storms Laboratory, has authored numerous scientific papers on tornado climatology, and was a contributing author on the recent Intergovernmental Panel on Climate Change's Fifth Assessment Report.
Yvette Richardson, associate professor of meteorology at Penn State University, is a Councilor of the American Meteorological Society and was a leader of the recent Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX2).
Robert J. Trapp, professor of atmospheric science at Purdue University, has published several articles on the topic of severe thunderstorms and climate change.
John Allen, postdoctoral research scientist at the International Research Institute for Climate and Society at Columbia University, has authored several recent journal articles on relationships between the climate system and severe thunderstorms.
Noah Diffenbaugh is an associate professor in the School of Earth Sciences and the Woods Institute for the Environment at Stanford University. He is currently a Lead Author for the Intergovernmental Panel on Climate Change.

Climate Scientist: 2 Degrees of Warming Too Much

By Andrea Thompson, Planet Earth Editor   |   December 04, 2013 03:27pm ET

A thermometer in the Earth shows increasing global climate sensitivity. Credit: Eduard Härkönen | Shutterstock View full size image

NEW YORK — Famed climate scientist and activist James Hansen has said it before, and he'll say it again: Two degrees of warming is too much.
International climate negotiators agreed in the Copenhagen Accord, a global agreement on climate change that took place at the 2009 United Nations' Climate Change Conference, that warming this century shouldn't increase by more than 2 degrees Celsius (3.6 degrees Fahrenheit) to avoid the worst impacts of climate change. But in a new paper published in the open-access journal PLOS ONE, Hansen and a cadre of co-authors from a wide array of disciplines argue that even 2 degrees is too much, and would "subject young people, future generations and nature to irreparable harm," Hansen wrote in an accompanying essay distributed to reporters.
The new study is a departure from the typical climate science paper, both for the wide variety of fields represented in the list of co-authors, which includes economist Jeffrey Sachs, as well as for the policy implications it raises, something climate scientists tend to shy away from. The authors also plainly state that humanity has a moral obligation to future generations, the type of statement scientists also tend to avoid.

Hansen and Sachs met with reporters here Tuesday (Dec. 3) in Columbia University's Low Library to discuss their study and their thoughts on the ongoing — and so far, largely ineffectual — effort to come up with a global plan to combat the problem of climate change and scale back emissions of greenhouse gases, primarily carbon dioxide.
"It seems like we're just charging ahead, burning any and every fossil fuel," Hansen told reporters. "There seems to be no real effort to get off that business-as-usual path."
Hansen, noted for his outspokenness on the topic of climate change and his willingness to venture into an advocacy role that many other climate scientists try to avoid, has previously voiced his concern about the 2-degree warming benchmark, saying in 2011 at the annual meeting of the American Geophysical Union (AGU) that, "the target that has been talked about in international negotiations for 2 degrees of warming is actually a prescription for long-term disaster."
At the time, Hansen was still the director of NASA's Goddard Institute for Space Studies in New York. He retired from that position in April, in part, to pursue political and legal efforts on combating climate change. (Hansen had already used vacation time to attend climate protests and was arrested or cited several times, including in front of the White House.)
Hansen began the new study three years ago as a way "to provide a basis for legal actions for governments for not doing their jobs for protecting the rights of young people and future generations" after a conversation he had with a legal scholar. Hansen plans to discuss these legal actions in more detail at the 2013 meeting of the AGU, taking place next week in San Francisco.
'We can't accept that'
Hansen and his co-authors say Earth's climate history suggests the level of emissions cited to stay below the 2-degree threshold would result in "a significantly different planet" than the one humans know today and the one seen during the past 10,000 years of geologic history, called the Holocene, during which human civilizations evolved and flourished. The authors note that many impacts of climate change are already visible, from the shrinking ranges of some species to the frequency of extreme heat waves. [8 Ways Global Warming is Already Changing the World]

Climate scientists James Hansen (left) and economist Jeffrey Sachs discuss a new paper on limiting carbon dioxide emissions with reporters at Columbia University's Low Library on Dec. 3, 2013.
Credit: Andrea Thompson

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The study also reveals conditions during another period called the Eemian, about 120,000 years ago, when temperatures are thought to have been about 2 degrees Celsius higher than they were from 1880 to 1920 (the period the researchers used for preindustrial measurements). Some studies have suggested that sea levels during that time were several meters higher than they are today; such an increase in sea levels would threaten, and could even inundate, coastal cities.
"We can't accept that," Hansen said. "If we have any love for our children and grandchildren, we can't accept that."
The aim in limiting greenhouse gas emissions should be to keep Earth's climate as close as possible to what it has been during the Holocene, say the study authors, adding that doing so depends on the cumulative amount of emissions released into the atmosphere throughout the industrial period, not just those emitted today.
So far, some 370 gigatons of carbon (GtC) have been emitted into the atmosphere over the span of the industrial era. Since then, the levels of emissions have continued to rise, as countries like China begin to overtake Western countries, which are responsible for the majority of the emissions released to date. Most of today's emissions come from the burning of coal.
To have a 50 percent shot at not surpassing the 2-degree warming limit, the fifth assessment of the Intergovernmental Panel on Climate Change noted that emissions should not exceed about 1,000 GtC by 2100. But Hansen and his co-authors argue this emissions' limit must be cut in half to draw carbon dioxide levels down to 350 parts per million from their current level of 395 ppm (the highest they have been in 3 million years) and to stabilize global temperatures. That's because of feedbacks in the climate system, such as Arctic ice melt and changes to cloud cover, as well as the potential melting of ice sheets. Taking such feedbacks into account, 1,000 GtC would likely result in a temperature rise of at least 3 degrees Celsius, the authors say, and the impacts from climate change would be "locked in" (impossible to reverse) for the future after 2100.
Part of problem is that even with current levels of emissions, the inertia of the climate system means that not all of the warming those emissions will cause has happened yet — a certain amount is "in the pipeline" and will only rear its head in the future, because the ocean absorbs some of the heat, delaying the inherent atmospheric warming for decades to centuries.
"This paper makes extremely clear what the costs of the current trajectory are," Sachs said.
The oceans also absorb some of the carbon dioxide emitted into the atmosphere, which affects efforts to reduce carbon dioxide levels in the atmosphere — as less carbon dioxide is emitted into the atmosphere, the oceans will release some carbon dioxide so that the two systems stay in balance.
Hansen and his co-authors say this emphasizes the urgency of starting to reduce emissions now; the longer the delay in starting, the longer it will take to reduce levels to 350 ppm. The paper gives this example: If emissions stopped in 2015, 350 ppm would be reached by 2100; but if they weren't stopped until 20 years from now, levels wouldn't settle to 350 ppm until 2300.

The Keeling Curve shows that atmospheric carbon dioxide levels are increasing, and at a faster rate each year.
Credit: Scripps Institution of Oceanography

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Of course, completely ending emissions is unrealistic, but the paper's authors argue that 350 ppm could still be reached by 2100 if emissions' reductions are started soon and if some amount of carbon is drawn down into the biosphere and soil through efforts like reforestation and more efficient agriculture.
The team calculates that if emissions' reductions began today, they would need to occur at the rate of 6 percent per year (whereas if they had started in 2005, they would only have needed to be 3.5 percent per year) to keep the global temperature within about 1-1.5 degrees Celsius of preindustrial levels.
"We conclude that it is urgent that large, long-term emission reductions begin soon. Even if a 6 percent/year reduction rate and 500 GtC are not achieved, it makes a huge difference when reductions begin," the authors wrote. "There is no practical justification for why emissions necessarily must even approach 1,000 GtC." [To Cut Carbon, A Decade Is Too Long to Wait (Op-Ed)]
Even with immediate, aggressive reductions, Hansen said it was likely that by the end of the century, temperatures would pass the 1-degree mark, but that they don't have to pass 2 degrees. He added that the 1-degree goal could be achieved in the long-term.
Of course, to "to de-carbonize the energy system deeply" would require a level of global cooperation not seen so far, Sachs said, as well as a new way of approaching climate negotiations, something he is working on with nations ahead of climate meetings in 2014 and 2015. "Our current approach is not working, and we need to do something very, very different," because if humanity waits, the "dangers are profound," Sachs said.
Sachs, Hansen and their co-authors advocate a carbon tax to limit emissions. Not only would such a carbon tax be relatively easy to scale to a global system, but it would also take the health and environmental effects of fossil fuels into account, putting clean energy — from wind to nuclear — on an equal footing.
"The solution has got to involve making fossil fuels pay their cost to society," Hansen said.
'Value-laden work'
The authors "make a compelling case, based on an exhaustive review of the science, economics and arguments about intergenerational ethics, that dangerous climate change should be defined by a threshold of 350 ppm (below current levels) and just 1C total warming relative to preindustrial time (we have nearly reached that already), rather than the typically cited 2C warming/450 ppm limit," Penn State climate scientist Michael Mann, who wasn't involved in the study, told LiveScience in an email. Mann said that he saw the paper as "less a scientific article than an extended commentary," but one that he thought was beneficial to the scientific discourse.
Stanford climate scientist Ken Caldeira was more apprehensive about the nature of the study. Whereas the information in the study was important and "a welcome addition to the scientific literature," he is "concerned about the presentation of such a prescriptive and value-laden work" in a piece that wasn't marked as an opinion, Caldeira told LiveScience in an email.
Caldeira also said the question of whether an emissions' reduction goal should be aimed at a 2-degree-warming threshold or a 350-ppm level of carbon dioxide was something "science alone cannot tell us" and that "our goals depend on our values." In the same vein, the choice of using a carbon tax over other possible tools to reduce emissions was a matter of judgment about political goals, he added.
Though they are aware of the difficulty and scale of the problem of beginning meaningful cuts to greenhouse gases, Hansen and Sachs remain optimistic that humanity can solve the problem. "This is a winnable proposition … but it's hard," Sachs said. "It's definitely the hardest public policy problem I've ever seen."
Follow Andrea Thompson @AndreaTOAP, Pinterest and Google+. Follow us @livescience, Facebook & Google+. Original article on LiveScience.

IMPROVING ON PREPARING QUALITY WORKSHEETS FOR SCIENCE LEARNING

IMPROVING ON PREPARING QUALITY

WORKSHEETS FOR SCIENCE LEARNING

Kanageswary Seger and Azizah Ngah Tasir

ABSTRACT

The aim of this research was to improve on preparing of quality worksheets which can enhance pupils to answer it. The respondents consisted of 27 pupils from Year 5 in Sekolah Kebangsaan Taman Segar, Kuala Lumpur.  The research methodology includes observation form, interview of science teacher, questionnaire and pupils formative test scores. The finding shows that giving worksheet to evaluate pupils at the end of the lesson provides useful information for teachers as well as pupils. Quality worksheet should focus on two main criterions which are the content and appearances of the worksheet. Good qualities of worksheet help pupils to score well. Thus, new teachers can apply the two main criterions to produce quality worksheets for their pupils.

1. INTRODUCTION

The process of assessment is the mechanism which carries out a judgment. (Teras, 2009). [2] Worksheet is a form of formative assessment. [1] Due to the poor qualities of worksheet that I had prepared in the past might caused the pupils to be demotivated to answer and complete it. So, I had put my effort to identify ways to prepare quality worksheet. In order to prepare quality worksheet, there were two main criterions that been focused. Firstly, the content of the worksheet and secondly, the appearances of the worksheet prepared. [1] Based on the study of my problem, I derived my research question as, “How the qualities of the worksheet are influence pupils to answer it and what are the improvements that I should do on the worksheet to get better result from the pupils?” 

2. METHODOLOGY

Research was conducted approximately for a month. Participants of this research were 27 pupils from year 5 Bestari.  The study was based on a mixed research design whereby it used both quantitative and qualitative data sources. Observation form was given to teacher to evaluate the worksheets. The second instrument being used to obtain the data was in the form of an interview. Three senior science teachers have been interviewed to get ideas to prepare quality worksheets. Questionnaire was given to pupils to get their feedback about the worksheet. Besides that, pupils formative test scores were collected. The data was analysed and presented in the form of table and graphs. A bar graph for questionnaire and a line graph for formative test score were plotted.

3. RESULTS

From the data collected I can state that quality worksheet help pupils to complete it correctly. As I improve the quality of worksheet, the scores of pupils were increased for each worksheet. Overall, criteria which most of the pupils agreed for quality worksheets are:  

Criteria
Content	Appearances
Short and clear questions	Relevant pictures
Simple language	Interesting layout.
Clear and simple instruction	Bolded key words
Suitable font and size

                   Table 1:  Criteria for a quality worksheet.

Therefore, when preparing quality worksheet minimum 5 criteria mentioned above should be consider. 

4. SUMMARY

The achievement of the action was all pupils were able to answer and complete the worksheets given successfully. The quality worksheet resulted in meaningful and productive science learning of the pupils. In view of these finding, I concluded that the usefulness of quality worksheets as an instruments to evaluating pupils and facilitating learning cannot be dismissed. However, the effectiveness and usefulness depends on how the worksheet are designed and prepared. Hence, teachers have to produce good quality worksheets that motivate pupils to answer it properly.  New teachers can apply the two main criterions to produce quality worksheets for their pupils.  In future I would like to continue my research on another tool of formative assessment.

REFERENCES

[1] Graham, B. (1998). Designing Effective Worksheets. Retrieved  on 1^st  March 2010

http://www.bgci.org/education/designing_effective_works/

[2] Teras,M.(2009). Summative Assessment: The Missing Link For Formative Assessment.

Journal Of Further And Higher Education. Vol 33 (1).

Corresponding Author:

Kanageswary Seger, Kanages_05@yahoo.com

WELCOME TO CIKGU KANA & ARU BLOGSPOT

WELCOME TO CIKGU KANA & ARU BLOGSPOT

Welcome to our personal site for resources in e-portfolio. We are Cikgu Kana & Aru are Science teachers. Through this page you can access my personal details, teaching & learning material and educational link list

I focus mainly on resources associated with or relevant to primary education system in Malaysia. Particularly in the science subject. This site is meant as a resource for students, academician, and administrators interested in e-learning.

The site includes links to many resources, but we are always looking for new resources, sites and feedback, so don’t hesitate to use the interactive features of this site – or just send me an e-mail.

So – happy browsing!.

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