Image: Wikimedia Commons/U.S. Air Force photo by Edward Aspera Jr.
The extreme weather, including a near-record number of tornadoes, in 2011 forced the debate of the impact of climate change on severe weather to resurface.
While there has been research into the subject, there are still many unknowns.
Is a Warming Climate Causing More Active Severe Weather Already?
Before examining how climate change may affect severe weather in the future, it is important to analyze whether the frequency or strength of severe weather has changed already with warming temperatures.
There is no strong evidence to support severe weather becoming stronger, more frequent or more widespread during the past 50 years in the United States as a result of climate change. One of the reasons that the change in severe weather is hard to track is the fact that the reporting systems have changed so much over time.
Ted Fujita developed the Fujita Scale, which measures the intensity of tornadoes by examining damage and estimated winds, in 1971. Meteorologists did not start rating twisters using the Fujita Scale until 1973.The National Oceanic and Atmospheric Administration (NOAA) went back through tornado reports from 1950 through 1972, retroactively rating tornadoes based on the damage information provided in the reports.
"Our best effort is to try to take care of those changes in reporting and indicate that we really haven't seen any changes [in severe weather]," Harold Brooks, Research Meteorologist at NOAA's National Severe Storms Laboratory in Norman, Okla., said.
However, with advancements in technology and social media, news of extreme and severe weather spread very quickly to all corners of the U.S.
"The big reason why we think that severe weather has gotten worse is our ability to communicate information about it. If you think back 100 years ago, a tornado that happened 10 or 20 miles away, you might not even be aware of it, if it didn't affect where you live directly. Now, you can watch people chasing tornadoes online live," Brooks explained. "So it's the fact that we are more aware and able to communicate that information about events so much better than we used to be able to that it makes us think severe weather has increased."
Future Climate Change Impacts on Severe Weather
There are still many limits to our knowledge of how severe weather will change as the climate warms, but some preliminary conclusions can be made from research so far.
Global Land-Ocean Temperature Index Graph from NASA's Goddard Institute for Space Studies.
"As the planet warms with more greenhouse gases, we really don't have very strong evidence as to what will happen with severe thunderstorms," Brooks said.
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24 Comments
Add CommentI'm very surprised Scientific American is publishing this article. The trend in many kinds of severe weather has in fact been firmly documented and attributed to climate change, including heatwaves and extreme precipitation.
Reply | Report Abuse | Link to thisTo single out only the data on thunderstorms and tornadoes and then to say that "There is no strong evidence to support severe weather becoming stronger, more frequent or more widespread..." especially as a stand along paragraph right up top is extremely misleading.
P.S. While the article cites Mr. Brooks in denying any connection between climate change and thunderstorms, some of the most authoritative scientists in the field on this subject, such as Dr. Kevin Trenberth and Dr. Gerry Meehl, both with NCAR, have a very different view. Scientific American does readers a disservice by failing to report the other side of the scientific debate.
Reply | Report Abuse | Link to thisthe USA is a fraction of the world's totsl area and any part of the USA a fraction of that.
Reply | Report Abuse | Link to thisNothing 'weird' about the weather where I live. No extremes.
Anecdotal media-driven events support of or not support the case for climate change is silly. Events are cherry picked 'to prove' whatever the agenda is.
Actually, SciAm usually beats the 'climate change is making everything worse' drum, so this IS the other side of the scientific debate.
Reply | Report Abuse | Link to thisThis article is misleading and disappointing. Virtually ALL of the credible evidence has established that the rapid rise in human CO2, methane and other greenhouse gases is damaging the climate and raising the sea level. Low-lying coastal areas have been wiped out already; many others are threatened. Vast numbers of people have already been displaced and many, many more will suffer. That there may not be more violent thunderstorms begs the question, and by reporting this without appropriate discussion of what we have to do to prevent further damage, you do your readers a great disservice.
Reply | Report Abuse | Link to thisThis article is a classic example of "Absense of evidence is not evidence of absense."
Reply | Report Abuse | Link to thisHaving lived in the same area for over 50 years, and frequently visiting a large section of the surrounding areas, I can say without question that anyone who claims the weather is not more severe and erratic than it was 50 years ago is either scientifically incompetent or lying.
Another excellent article SciAm. There is 100% evidence that a warming climate causes severe storms. It is recorded throughout history that when the climate heats up, you have more severe thunder storms, snow storms, etc., and heat waves. This has been happening throughout the history of the Earth. To return our planet to normal, we need to immediately stop burning fossil fuel. I did not say to stop using fossil fuel, I said stop burning fossil fuel. With electric cars and clean energy power plants, like: geothermal (above or below ground), solar, wind and wave (both ocean and river) we can return our planet to its normal cycle withing a very short period of time...a lot faster than you think. ...start mass producing electric cars and geothermal - above and below ground.
Reply | Report Abuse | Link to thisI am not sure what "firmly documented" means except that it might mean "vigorously reported without much study". While I suspect that the earths climate is warming and concede that there is some possibility that it has been exacerbated or caused by human activity, I am not ready to jump from those suspicions to validating every possible negative consequence. Certainly the change that could be caused by global warming will likely be inconvenient for most of us and catastrophic for a few. There will also be changes that will benefit some. It's not bad or good. It is change.
Reply | Report Abuse | Link to this"...wave (both ocean and river)"
Reply | Report Abuse | Link to thisWhat river do you live near that has waves steady or big enough to generate useful power? I think you meant wave power in large lakes, seas and oceans, but in-stream hydroelectric power in rivers. All good ideas.
So is your conclusion based on a rigorous examination of the evidence or is your lumbago just acting up. A feeling isn't enough to make a scientifically valid conclusion.
Reply | Report Abuse | Link to thisEven if the US completely converted to zero emissions technologies, the rest of the world cannot afford to make such drastic and expensive changes. Your sweeping pronouncement is the equivalent of "Let them eat cake." You are living in a fantasy world where you think that you can just wave your money powered magic wand. Most places it doesn't work that way.
Reply | Report Abuse | Link to this"...the rest of the world cannot afford to make such drastic and expensive changes"
Reply | Report Abuse | Link to thisYou assume that all changes have to be drastic and expensive. Some options are, but perhaps some are not, or not so much. Remember that many places are building new capacity that did not exist before, and why must they aspire to the same levels of wasteful consumption that the 'developed' nations presently demonstrate?
Good point faucets. Science is always battling the anecdotal 'certainty' of the Mr Peabodys of the world. the Peabodys don't want to be confused by evidcence...they 'just know'....and don't you go tellijg therm any different...afterall, Grandma smoked a pack of cigarettes every day and lived to be a hundred....when hit by a car.
Reply | Report Abuse | Link to thisIt is temperature difference between two different regions that generates severe weather. Extreame heat or extreme cold alone does not do it. If the earth warms up in the cooler lattitudes but remains much the same in hotter latitudes the temperature difference will be lowered & will decrease the severity of storms. Major storms that develop over tropical or subtropical regions move heat away from those regions to cooler areas. That is what drives all heat engines.
Reply | Report Abuse | Link to this"Low-lying coastal areas have been wiped out already; many others are threatened."
Reply | Report Abuse | Link to thisYou make it sound like Godzilla is rampaging around. Many are threatened, yes, even to the point of permanently evacuating large populations; but I'd be curious to know what your sourcing is on those which 'have been wiped out already.'
Perhaps if you tone it down a notch and keep things within the bounds of the actual, the denier crowd wouldn't have such a field day playing off the extremist views suggested by the kind of exaggeration you've engaged in above.
T
First, it was supposed closing of North Atlantic sea current circulation and new ice age. This didn't happen.
Reply | Report Abuse | Link to thisThen, it was supposed global warming and hot winters. This didn't happen.
Then, it was supposed that temperature keeps normal but extreme events happen more often. This also didn't happen.
Only one happens: money coming to climate research.
@DHWeiss
Reply | Report Abuse | Link to thisWhat are you smoking? Last time I went to the beach my grandparents were playing. I assure you it didn't disappear below the rising sea.
Unless sea level rises only in remote places and stays the same at home?
@ttheobald
Reply | Report Abuse | Link to thisWhy you believe that moderate climate believers are any more truthful than extreme ones?
Put it simply: warmists want taxpayers to pay huge sums for study and fight global warming, but deny both accuracy or responsibility for their predictions.
Was any scientist or environmental organization prosecuted for fraud after false claims that Netherlands disappears under waves by now or Himalayan glaciers will melt by 2035? Anybody was even fired from his seat in some climate panel? Nope, they all get huge grants for more climate research and produce new alarmistic predictions.
Jerzy
Reply | Report Abuse | Link to thisAgree. All this seal level rise must be in remote places. We visited an almost 200 year old whaling station that has stone ramp that could be used today wirthout an inch of adjust ment up or down.
...oops, this doesn't fit the doom and gloom extolled by the eglobal warming cultists... the end is nye!
The article uses inconsistent yardsticks to support a claim that extreme events increase is basically observational bias. It isn't.
Reply | Report Abuse | Link to thisThere never was a claim that tornadoes (or hurricanes for that matter) were increasing in frequency or severity. There are claims about anomalies (out of season, dissipative power, unusual locations, pattern changes).
http://www.ncdc.noaa.gov/oa/climate/severeweather/tornadoes.html
The historical chart 3/4 of the way down the page indicate the chaotic nature of annual tracking.
The USA extreme heat anomalies is a known:
http://www.ucar.edu/news/releases/2009/images/temps_2.jpg
The USA extreme flood damage increase is a known (save the 'increased property values' angle - it's set against massively increased flood response initiatives).
Globally, 2010 was the wettest year in the records (1880). And that's a lot of extreme weather. The extreme weather swings of last winter, and the scorching drought in Texas last summer, are not observational bias. It's a respect for the anomalies that occur instead of denying the general when a specific anomaly factor appears to be missing.
Owl, thank you for understanding that there are more than two sides to an issue! An article which speaks in support of climate change may not necessarily be a good or accurate one, and bad arguments should be shot down, even if they speak in favor of "your team".
Reply | Report Abuse | Link to thisGEO- The USA is about 2.7% of the Earth's surface. Nothing weird about our weather either.
Reply | Report Abuse | Link to thisI am going to have to beg to differ. While I know that I am going to be crucified once again by those of you that buy AGW here is a reference that constains very enlightening plots of the various data sets that are used to support AGW:
Reply | Report Abuse | Link to thishttp://www.oism.org/pproject/GWReview_OISM150.pdf
Without even reading the text and looking at the various data plots you should be ashamed to state things like 'The trend in many kinds of severe weather has in fact been firmly documented and attributed to climate change, including heatwaves and extreme precipitation.'
Now, why is this not published in a 'peer reviewed' journal you ask? Is it because the peer editors of viewpoints that are contrary to their own quite often supress such articles? I think back to a debate that raged is the geologic community regarding plate tectonics and the amount of rancor that was spewed by those that did not want to look at the data in an unbiased manner.
If you want to jump in and call me a 'denier' feel free but unless you can explain away the apparent correlations in figure 13 of the afore mentioned reference I have no use for your opinions or interpretations of what has or has not been proven regarding AGW.
Yeah yeah I did already over here...
Reply | Report Abuse | Link to thishttp://www.scientificamerican.com/article.cfm?id=merriam-kansas-peak-oil-and-climate-change