Dr. James J. O’Brien
Climatologist for the State of Florida
Dr. O Brien is the Robert O. Lawton Distinguished Professor of Meteorology & Oceanography and Director of Center for Ocean-Atmospheric Prediction Studies at Florida State University in Tallahassee, Florida. He was appointed as State of Florida Climatologist in 1999.
Full Biography
Moderator: Welcome to the globalwarming.org live chat. We are now taking early questions for Dr. O’Brien. Please keep your questions scientific in nature, as Dr. O’Brien is a climatologist, not a politician. And once we get underway, please remember to REFRESH THE PAGE to see the questions and answers as the hour progresses.
Moderator: Okay, here we go. Marlo in Washington asks a two-part question –
* Is a storm powerful enough to suck stratospheric air down to ground level theoretically possible?
* Is there any evidence in the paleoclimate record that something like that has happened before? In the movie, the Dennis Quaid character mentions that, in Russia, wooly mammoths have been found frozen in ice with vegetation still in their mouths. The mammoths appear to have been flash frozen. Is TDAT’s scenario a plausible explanation of how that might have happened?
Dr. O’Brien responds: Great questions.
I am not an expert on paleo climate, but I understand the oceans. Even now, stratospheric air extends into the upper troposphere in a big midlatitude storm. But this air never reaches the ground. When air is forced to sink. it must warm up adiabatically. the rate is about 1 degree F / 1000 ft. Don’t hold me to the exact number. In this mode, I can’t look it up.
All of us have felt down drafts from thunderstorms which are cool air, but the air has warmed maybe 30 or 40 in its descent from the upper troposohere.
I can’t comment on previous Ice Ages, but maybe the animals were too stubborn to quit eating!
Moderator: Randy in Poland asks a more general global warming two-part question:
* If global warming is human-induced in significant part, why is the South Pole getting colder?
* And, how can CO2 levels be the cause of warming when they have been even higher in the past than today and higher in Ice Ages?
Dr. O’Brien responds: I will try to answer your questions…
Yes, CO2 levels have been higher in the past, and it is true that they provide a delay of heat radiated out to space. In my opinion, the Earth’s climate system of air, water and ice and land, may react to the extra heat held in by CO2 in ways different than warming the biosphere.
In the Southeast U.S. all the urban stations are warming up, but the rural stations are cooling down. The rate is 2-3 degrees F in a hundred years.
The reason for the cooling is the land use change from swamps to agriculture. All the moisture from the wetlands helps reduce the radiation of heat on clear winter days.
The global warming persons would say yours and mine are only local effects. The heating of the cities is due to concete, asphalt, cars, people, etc. It is not due to CO2.
We need to remove the heat island effects from our temperature records.
Moderator: Jim in Virginia asks –
Is it really possible that polar ice caps could melt enough to cause a “desalinization tipping point” that would significantly alter oceanic currents, as in the movie? If so, how would the oceanic currents be altered and what would the effects be on the rest of the climate?
Dr. O’Brien responds: It is possible that lots of rains and melting could cap the Greenland and Gin Seas and reduce the sinking of cold water. Could it stop it? I don’t think so.
We have had periods of changes in salinity in the past 50 years which have modified the climate of the ocean in the North Atlantic which in turn really affected the climate of Europe and eastern North America. But nbot anything like the movie. The best scientists say that “rapid climate change’ like this would take 50 to 100 years.
Moderator: Erik at Johns Hopkins asks –
In the movie, the temperature in the North Atlantic Current off Greenland dropped 13 degrees (Celsius, I guess). What is the temperature normally, and what would happen if if it dropped this much?
Dr. O’Brien turns the floor over to a colleague: This is one of my recent Ph.D. students, who knows the answers better than me, Eric.
Eric: I have seen the ocean drop 8 degrees C or 15 F in a week, but this was due to upwelling of cold water from below where the normal surface temperatures were 26 C. This was in the equatorial Pacific. In the North Atlantic this can’t happen because the top to bottom temperature is only a few degrees.
And the air cannot remove the hear fast wnough. if you start to cool water by evaporation, fog will form and insulate the continuing evaporation.
Moderator: Chris in Virginia asks –
Assuming that global warming is occuring will we ever be able to estimate how much is natural variation and how much is due to human activities?
Dr. O’Brien responds: Nice question. Of course any variation in the sun will be felt in our climate. I am not an expert on solar variations. Recently however, I read that pollution from increasing pollution was reflecting sunlight and reducing short wave energy (light) from reaching the ground and ocean and turning into longwave energy (heat).
I would guess this would lead to global cooling! It is certainly a complicated issue.
Moderator: Frances in Maryland asks –
We’ve heard in the past about the strong effects El Nino has on weather events. What’s the story with El Nino now? Is anything significant happening?
Dr. O’Brien responds: Now I really like this question!
El Nino has always occured. We have records from peru since 1500 and earlier from corals from the Galapagos.
El Nino occurs on average every four years. there is also La Nina which means cold water off Ecuador.
El nino will be back again, but probably next winter. there have been times when it went away for 10 years or so.
Keep in mind El Nino is a good dude for the U.S. El Nino kills Atlantic hurricanes! It brings rain to the Southeast which suppresses wildfires, particularly in Florida. El Nino causes bad climate in many parts of the world, but for the U.S. it is mostly good.
Moderator: Drammach asks –
Doesn’t much of the Global warming we are experiencing have to do with Solar activities rather than human activities..?
Dr. O’Brien responds: Nice question. of course any variation in the sun will be felt in our climate. I am not an expert on solar variations. recently however I read that pollution from increasing pollution was reflecting sunlight and reducing short wave energy ( light) from reaching the ground and ocean and turning into longwave energy ( heat).
I would guess this would lead to global cooling! It is certainly a complicated issue.
Moderator: Mary in Louisiana wonders –
Early in the movie, the change in the ocean currents causes a big hailstorm in Japan, snow in India and devastating supertornados in Los Angeles. Are any of those scenarios close to reality?
Dr. O’Brien responds: This is hollywood!!
The hailstones are too big to stay upstairs long enough to grow this large. Every now and then in our west there is a freak storm that produces a big piece of ice. It is made up of the combination of many hailstones.
I would guess that we have had really enough severe storms in the United States and other lands that would have produced these big stones if it was possible! There is plenty of snow in northern INDIA. It is possible to have a snowstorm in central INDIA. Hey it has even snowed in ORLANDO and where I live in TALLAHASSEE.
I believe I have read that tornadoes have been seen in every state in the US. but they are near impossible in southern California.
Moderator: Dan asks –
Since the Earth has a natural greenhouse effect, which is necessary to keep the earth from freezing, and the warming itself may be the natural progression of Earth evolution, but if not, has the possibility of Global warming being caused by the removal of Fossil fuels from the earth’s crust ever been considered? Fossil fuels could be a natural insulator between the earth\’s crust and the extremely hot core and with this insulation being depleted couldn’t the warming be coming from below rather than above?
Dr. O’Brien Responds: Great question Dan
Again not my field. but geophysicists have measured heat flow from the earth for a long time. when we have volcanoes on land they give off a lot of heat but only in a local region . There real danger to the climate comes if lots of ash is pushed up into the stratosphere where it can insulate us from the sun and cause what is called ”nuclear winter.” There are a lot of volcanoes under the ocean and many rifts in the plates through which boiling lave oozes. ( I like that word!). The effect is almost never seen at the top of the ocean where we sail and swim. the high specific heat of seawater easily absorbs the heat locally.
Moderator: Carl in Colorado asks –
The movie had three of those “superstorms” starting up at once near the North Pole and then moving southward. How likely is that to happen after the temperature in the North Atlantic changes? Is even one likely?
Dr. O’Brien Responds: Don’t know. But lets ask MOTHER NATURE.
When we have a monstrous hurricane in the Atlantic, we dont have a big sister in the Pacific. When we have a monster typhoon in the Pacific we dont get a category 4 or 5 in Atlantic. There can be several storms in one basin at a time. This is due to very unstable circumstances that breeds a pack of storms one after another.
Moderator: Marian asks –
When I was taking geology, there was a considerable amount of speculation regarding the long-term effects of global warming. The immediate agreed on effects seem to be an increase of heated water at the top of the oceans and an increase in melting of the ice caps which will affect water levels around the globe. I’ve also heard it suggested that the increase of fresh water from the melting ice caps into the worlds oceans might change the deep water currents that move throughout the world which would affect temperatures further.Have any of these theories been studied in-depth and is there any way to lessen or halt their progression? Is it reversable?
Is there any way that global warming has a historical basis (beyond El Nino/La Nina or volcanic activity)?
Dr. O’Brien Responds: If there is substantial global warming, I would guess the ocean will warm up and some glacial ice and floating ice will melt. There are many scare stories about sea level rise. Here is the best truth!
Everyone who estimates sea level rise from tide gauge stations gets the same answer about 2.1 mm /year . This is about 10 inches in 100 years. recently scientists have looked at altimeters which measure sea level everywhere and have found 14 inches sea rise in a hundred years. the difference is NOT global warming but a better measurement.
All the scientists who have looked for acceleration of sea level rise have not found any. much of the observed sea level rise is due to crustal rebound from the ice ages.
Other examples, New Orleans is sinking because they messed up their wetlands so sea level is rising in New Orleans. There are many other examples there are the theories you mention. They have not been measured in depth.
Moderator: Thank you all for participating, and thanks to Dr. O’Brien. This concludes our online chat. Check our website for the next one.
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