It’s Hot But Don’t Blame Global Warming
By Cynthia Barnett – 2/1/2009
FloridaTrend Magazine
Morton D. Winsberg fell in love with Florida more than 50
years ago, but the Illinois-born geographer never quite got used to the dog days
of summer.
In recent years, the Florida State University professor emeritus and author
of a book called “Florida Weather” began wondering: Is global climate change
making Florida’s hot season longer and hotter? With help from geography students
and researchers at FSU’s Population Center and Florida Climate Center, Winsberg
and co-author Melanie Simmons gathered and analyzed temperature data from 57
Florida weather stations going back six decades.
Their research showed that the hot season in Florida has gotten a lot hotter
— and longer — in some places, but not at all in others. The change, however, is
unrelated to global warming, the increase in the average temperature of the
earth’s atmosphere. Rather, they found, it’s a function of the lesser-known
phenomenon of local warming. The analysis “shows that weather can be very
local,” says Winsberg, “and also that weather can be a function of population
growth.”
Winsberg found the most notable climate changes along the state’s
southeastern coast, where development and wetlands drainage have been heaviest.
In most areas he analyzed, the heat is getting more intense. Of the 57 weather
stations, 49 saw an increase in the number of days with an average temperature
of 80 degrees. When it came to the length of the hot season, the biggest
increase was in Hialeah, with a 72-day increase, followed by Miami, with a
45-day increase.
Neither the intensity of the heat nor the increasing number of hotter days
was related to water temperatures in the Atlantic and Gulf, a fact that
surprised Winsberg. The heat trends also weren’t consistent across the state. In
fact, some areas, notably in the northeast part of the state, saw a shorter hot
season and a decrease in the number of dog days.
That evidence leads Winsberg and FSU meteorologists to blame the hot spots on
local land-use changes that accentuate the urban “heat-island” effect — the
pools of heat that large, dense concentrations of people produce in their local
climates. Cutting down trees, draining wetlands and pouring concrete all make a
place hotter, as anyone who’s walked across an asphalt parking lot on a summer
day knows, Winsberg says.
|
Geographer Morton Winsberg’s research suggests that local land-use changes — urban development and draining wetlands — may be contributing more to local climate change than global warming. [Photo: Jeffrey Camp] Contagious Energy Geographer Morton Winsberg retired a decade ago, but you wouldn’t know if from his teaching load, his research output and the hours he spends on the Florida State University campus. At 78, Winsberg no longer worries about getting his work published or being recognized by fellow academics. He had even been teaching Latin American and Florida geography at FSU for free until last year, when FSU put him back on the payroll. Winsberg is happy taking advantage of office space, grad students and GIS equipment so he can keep digging into weather and other interests. “I don’t play golf,” he explains. “I prefer to play with aggregate data.” Winsberg spent his career traveling the globe and writing about 100 research papers on topics as diverse as Jewish agricultural colonization in Argentina and Irish suburbanization in Boston, Chicago and New York. His favorite trip: Backpacking across northern Spain, following a medieval pilgrimage route to Santiago de Compostela, reputed to be the burial site of St. James. Winsberg says he dreaded becoming the sort of retiree “who kept up with the world via “I wanted to keep feeling useful and to be useful,” Winsberg says. He passed up royalties from his “Florida Weather” book so it would be more affordable ($16.95 at upf.com). In addition to his work on weather, his post-retirement writings include the book “Atlas of Race, Ancestry, and Religion in 21st-Century Florida.” He is currently researching the locations of megachurches, particularly those within metropolitan areas. Colleagues say he’s the only “emeritus” professor they know who spends as much time on campus as he did before retiring. “I’ve never talked to Mort about weather when he was not extremely excited about it,” says Melissa Griffin, Florida’s assistant climatologist. “He has this energy that flows out of him, seeps out of him, and other people catch it.” |
On a regional level, state climatologist David Zierden says, historical
records show that southeastern Alabama, Georgia and north and central Florida
have not experienced steady warming, but rather relatively warm periods, such as
the 1930s through the 1950s, followed by relatively cool periods, such as the
1960s through the 1980s.
|
State climatologist David Zierden says Winsberg’s data bolsters his belief, backed up by other Florida studies, that climate changes driven by land use ‘are as important or more important in Florida than what has happened here to date due to greenhouse gases.’ [Photo: Ray Stanyard] |
Heavily drained or developed areas bucked those trends, however. The most
dramatic example in Winsberg’s study is the difference between Belle Glade, in a
part of the Everglades drained for sugar production, and undeveloped Everglades
City. Since 1950, Belle Glade has seen a 32% increase in its number of dog days,
while Everglades City has seen a 3% decrease. The transformation of swampland
around Belle Glade to farmland appears to have caused a significant rise in
temperatures. “The draining of the Everglades and the upturning of all that
black soil has really changed the local climate in that area,” says Zierden.
The idea of local climate change may seem contrarian at a time when
scientists and policy-makers focus on global warming and its causes, primarily
the release of carbon dioxide and other greenhouse gases into the atmosphere.
But Florida’s top global warming scientists, including Harold Wanless, chairman
of geological sciences at the University of Miami, agree that greenhouse gases
don’t seem to be impacting Florida’s temperatures. When it comes to global
warming, Wanless says, sea-level rise — caused by warming elsewhere,
particularly the Arctic — is the chief threat to Florida. Wanless predicts
Florida’s seas will rise three to five feet by century’s end.
As state and national policy-makers work to mitigate damages from the rising
seas, Winsberg says he hopes local officials and Floridians will use his data to
think more wisely about land-use changes and wetlands drainage.
“People just dread when the hot season begins, and they are so relieved when
it’s over,” says Winsberg. “We don’t want to extend the suffering.”
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Florida is warming w/the limiting temp for citrus fruits moving south?
Pielke Sr’s analysis of Florida suggests that urbanization, drainage enhancement & unirrigated crop conversion dries the land out w/less summer rainfall & greater extremes of high/low temps.
Was the longer hot season in Miami a bad thing? I have a feeling that it translates to billions of dollars extra over the years. Do the politicians really want to go back to cooler times? (less UHI?)
Anthony,
Are you familiar with the UHI study done in 1972 by T.R. Oke, “City Size and the Urban Heat Island”? You can find it by googling UHI and Oke. He compared night temperatures in rural areas with night temps in ten settlements with populations from 1000 to 2 million. His data was subjected to stepwise multiple regression analysis and yielded the formula:
Delta T (urban-rural) = 1.91 log P – 2.07 sqrt(u) – 1.73
where P is population and u is regional windspeed. (This assumes cloudless nights.)
What is surprising is the logarithmic relation between Delta T and P, and the amount of Delta T for even small settlements.
For example,
Delta T is over 2 degrees C for settlements of only 1000 people, over 5 degrees C for population of 10,000 and over 8 degrees for populations of 100,000 people.
If real, this changes the perception of “Rural” and “Urban” and shows how the GISS temperature records are meaningless without UHI adjustments.
It explains why the historical records from Great Britain show more of an increase in average daily minimum temperatures vs the avg. daily maximums, as the UHI is about an order of magnitude stronger in night than in the day.
It also might explain why other researchers found little UHI effect when comparing historical records of sites. The logarithment increase in UHI with population would mean that the stations they classified as “Rural” (with assumed zero UHI) actually had a large UHI effect.
We need more studies like this with data from cloudy nights, differing times of the day and different wind speeds.
Also unknown, as far as I can find, are studies on how these large numbers for local UHI (on calm and clear nights) affect the monthly temperature averages.
Dave (02:10:10) :
You might want to go over to Climate Audit and read the several threads on the accuracy and reliability of ice cores to report temperatures. If my fading memory is correct, there seems to be some question about whether the dissolved CO2, which is the indicator for temperature, actually remains unchanged in each strata while the ice is in place, and after the core is removed.
Well, as one who majored in geography for a couple of years, it is nice to see a study like this. (Actually, as I recall it, “climatology” was a part of the study of geography in those days. I remember one of my professors using having all the students in a class I was taking, somewhat like Winsberg, keep a record of rainfall where we all lived, so we could study and see how local topography influences microclimate. I suspect my “training” in climate studies — I went on to graduate in economics — is at least the equal of many of the so-called experts in the field.)
Willem de Rode (01:42:15) :
but finally the problem remains a global one namely overpopulation in this approach.
So what should we do about it? Anything? Why? Taking Florida as an example, if Miami-Dade is overpopulated, and this is causing the dog days of summer to last longer than their liking, they are free to move somewhere else, aren’t they?
Actually, is this really a “problem”? Calling something a “problem” implies that something needs “fixed.” And that raises the question of how, which will segue into who, will do the fixing. You didn’t say it, so I’m not attributing this to you, but my fear whenever I hear of a problem that needs fixing is that someone is going to decide that the .gov needs to be the one fixing it, which usually means a raid on my wallet or a restriction of my liberty, or both. Which is why the “climate change” issue is so contentious: it is being used to promote all kinds of expensive solutions and atrocious intrusions on individual liberty.
I’m not sure I see the “problem” here.
Prevailing winds from jet stream latitudinal/longitudinal relocation. The Jet stream (which can fly straight or wave and loop like a flag in the wind) allows sudden warm or cold air to flow into areas resulting in sudden temperature changes. If the jet stream shift stays around for a season or two, you can stay mighty cold or mighty warm in a hurry depending on whether it is blocking Arctic air, or bringing up warm tropical air. The temperature shift will be dramatic.
I meant, “…whether it is allowing Arctic air to drop into more southern locations, or bringing up warm tropical air.” My thought stream got interrupted by a need for coffee.
Forget the heat island, the interesting part is the blue areas in the mid and north of Florida.
The caption to the map says: “would have followed the general cooling trend seen elsewhere in the Southeast U.S.”
What cooling trend? Is not the Southeast U.S. part of the global globe?
Volcanic Activity, Massive solar flair, Tectonic Activity, Polarity shift in the polls (North and south have upended before), and pretty much anything else you can imagine. Most are not much more than ‘ideas’ since we really do not know what causes major changes over short times without other evidence.
You have to look at other data sources such as geologic to find a coloration if possible.
Wetland drainage is a critical component that is not modeled by the NASA team. he heat capacity of water overwhelms air temperatures. Over 50% of the wetlands have been lost this century and a large percentage (over 90% in California) have been channelized so that the cool waters are not stored and slowly released. Many of the threatened species are connected to wetlands.
People who don’t understand the science of the proposed Human Climate Warming, are believers who really just want to see the environment protected. We should spend our money fixing wetlands instead of throwing it away on dubious CO2 fixes. Fixing wetlands will help more species and is a good climate hedge whether it gets warmer or colder.
Dave, I woud be deeply suspicious of a claim that “the ice cores showed a sudden 5 degrees C movement, and the change came within a year, perhaps it was even instantaneous”. My understanding is that icecores have a much more limited resolution- look how long it took to work out that temperature changes preceded those of CO2 by some 800 years.
Mind you, it is the BBC that is saying this and we all know how unbiased they are when it comes to AGW and “tipping points”.
To Dave (02:10:10) :
Interesting that they highlighted the movement but didn’t indicate direction? I’d guess volcanic activity for a single year shift if downward? Just throwing something on the wall.
This is a fascinating study though in light of its impact on our understanding of UHI and controlling for it in data provided by weather stations.
Since I plan to retire in 3 years, 8 months and 14 days (not that I’m counting) in the Ocala/Leesburg area of Florida this is welcome news that the area is cooling over the last 50 years. 🙂 I don’t mind hot, humid weather having spent too much of my youth in SouthEast Asian areas that feature that type of weather, but having it not so hot as it used to be is a good thing.
Off topic but related. See this post by Dr Pielke, Sr on the observational evidence for global warming via the ‘Ocean Heat Content’ metric. http://climatesci.org/2009/02/09/update-on-a-comparison-of-upper-ocean-heat-content-changes-with-the-giss-model-predictions/.
Interesting that observation vs predicted model results for ocean heat content is SO far off (0 x 10^22 Joules observed vs ~6 x 10^22 joules predicted over the last five years). Is Dr. Hansen ever going to be asked to respond publicly as to why his predicted climate model results are not reflected in observational measurements?
The real irony about global warming and local warming is that if more land is drained to make room for sugar cane crops for alcohol production (as is done in Brazil but admitedly not here) then renewable fuels could increase the local temperature. Now at least sugar based ethanol can deliver a positive energy yield (compared with the corn based product) but will an increase in local temperatures cause increased used of electricity for air conditioning and will that net result be more energy used locally.
“with little or no land use change, areas showing a longer hot season would have followed the general cooling trend seen elsewhere in the Southeast U.S.”
so…it’s UHI masking cooling rather than cooling masking warming.
Does this not fly in the face of GISS land temperature measurements that do not agree with satellite measures?
Having spent much of my life in Florida. In fact in Kissimmee near the Disney growth area I am well familiar with the findings of Winsberg and Barnett. I lived there from 1960 – 1997. the amount of growth and wetlands drainage was terrible. Now they are worrying about where they are going to get potable water. Yes it is over population and the destruction of some of the best farmland in the United States also large amounts of drainage. The drainage started in the 1880’s and only increased as the climate there became more popular.
Florida history is full of reference to the changes made there. In this case I must agree it is localized warming but it is man made.
Bill Derryberry
Bill Marsh (07:54:05) :
Here’s the money quote from Dr. Pielke’s post:
“While the time period for this descrepancy with the GISS model is relatively short, the question should be asked as to the number of years required to reject this model as having global warming predictive skill, if this large difference between the observations and the GISS model persists.”
GIGO.
Thanks to those who answered my question.
The main response I seem to be getting is that the data was probably duff, and that there arent really events where you get a discrete movement in temperature.
Apart from the response which suggested that the last ice age ended very quickly.
I am sure though that I read somewhere evidence that the glaciers that created the Great Lake depressions apparently melted away in no time at all.
Would still like to keep the question open. Is there any evidence for large and discrete temperature changes on earth? And by that I mean a change of 4 – 5 degrees C, happening within a year.
If there is evidence for this, I would like to see a lot of money spent on it trying to find out why it happens.
Could they please do a similar study looking at the minimum temperatures in winter in Florida? We’ve had more nights below 20F here in north Florida this year than in the past few years. The cold this year has noticeably killed a lot of vegetation which has the potential to turn Florida into a bushfire tinderbox if there’s a dry spring/summer later in the year.
Dave (02:10:10) : asks about quick changes to global temperatures.
Chaotic systems like our atmosphere can experience movement from one stable state to another. This process can start slowly and reach a tipping point where it accelerates to the next stable state.
This may occur between ice ages and interglacials. Since ice melts at a specific temperature you could see a slow warming that was not sufficient to start melting. Then, as melting starts it quickly warms due to less albedo, etc., which causes more melting and you have a quick rise in temperatures.
Why are the SOHO sunspot and other pictures more than 2 days old ???????
http://sohowww.nascom.nasa.gov/data/realtime-images.html
No conspiracy just curious ???
It is so pleasurable to see stories of great people like this!
This caught my eye:
“Since 1950, Belle Glade has seen a 32% increase in its number of dog days,
while Everglades City has seen a 3% decrease. The transformation of swampland
around Belle Glade to farmland appears to have caused a significant rise in
temperatures. “The draining of the Everglades and the upturning of all that
black soil has really changed the local climate in that area,” says Zierden.”
More direct empirical evidence for the negative feedback exerted by water!
Long time reader, first time poster.
As a motorcycle rider, I can tell you that I unscientifically verify the local warming theory all the time. In Nashville, Tennessee the dense urban core quickly gives way to heavily wooded areas. There’s a huge park with dense forest just four miles away from downtown. The park has a narrow one-way road that meanders through it, but very few sections of it receive any direct sunlight. I took a ride once on a warm July evening that went through downtown. I was on the main drag, so I was going around 30 MPH on average. I was warm and toasty regardless of my speed in the urban area. As I got further out of downtown–even just a mile–it got noticeably cooler. When I was on the road going through the heavily forested park area, I was shivering, without going any faster than I went at any point in the urban roads. It really is common sense. The unshaded asphalt soaks up heat during the day and radiates it at night. The asphalt in the park is totally shaded all day, so there’s no extra heat from it at night.
Last Sunday, we had a beautiful 70-degree afternoon just a few days after a huge cold front had passed through. I took my motorcycle out for a 30 mile ride, and within one mile of road I could alternate between shivering and basking in gentle warmth.
It seems obvious, but for some reason it seems that a segment of the population wants to assume it’s a major disaster.
Some commenters ask me how it would be possible that population-growth induced weather changes can become a global problem. More than half of the global surface is water and so unpopulated. And even on the landpart the humans are concentrated on rather small areas ? Thus any problem associated with that can never be global ?
I think that is a very short-sighted vision. If any problems are associated with population growth they will be best sensible in these extreme dense populated zones. These area’s are spread over the whole globe, but that doesn’t matter. The consequenses of the weather changes will be felt by most of the humans because they live in these problem-areas.
Thus I think it is couting angels on a needlepoint to get involved in a discussion whether the article describes a global phenomenon of local wether changes or not.
The article describes very clearly a antropogenic induced warming that could influence weatherpatters all over the globe. And the consequences could be very negative for the humans, wherever they are on the world.
So stop chasing phantoms by insulting CO2 of this warming. Stop fooling ourselfes by trying to make ourselfs believe that it is not a global phenomenon. Just let minimize the impact of human presence on this earth. We all, the all globe, would benefit from it.
“At least it’s a “dry” heat!”
Dry and Florida are two words that have a hard time going together.