Recent stories on ABC’s World News Tonight have shown conflicting takes on whether global warming has caused the current hurricane season – the first story supporting the theory, the second story (with a different anchor and reporter) dismissing global warming’s role. On World News Tonight Saturday on July 9, anchor Dan Harris relayed that scientists are wondering whether global warming is responsible for the early creation of strong hurricanes in the Atlantic Ocean. While introducing a story by reporter John Berman detailing the predictions of scientists that there will be stronger hurricanes in the future due to global warming, Harris introduced the story by saying, “Scientists have been surprised by the intensity of recent storm systems, and they're wondering whether global warming may be playing a role.” (Berman’s report itself did not specifically address the issue of whether the current hurricanes have been affected by global warming, but instead focused on predictions that future hurricanes will be stronger due to global warming.) Last Friday, six days later, on the July 15 broadcast, reporter Jeffrey Kofman filed a story detailing several converging factors that are causing the recent strong storms, at the end of which he concluded: "Scientists say this is not because of global warming, it is simply a lot of cyclical climate patterns conspiring to create the perfect conditions for a long season of perfect storms."

A complete transcript of the July 9 story which promotes the possibility of global warming influencing the current hurricane season, as well as future hurricane seasons, is below:

Dan Harris: "Scientists have been surprised by the intensity of recent storm systems, and they're wondering whether global warming may be playing a role. At its peak yesterday, Dennis was the strongest July hurricane ever reported off the U.S. coast. As ABC's John Berman reports, that record may not stand for long."
John Berman: "In Florida, they know just how powerful hurricanes can be. Over the last year, they have been reminded more times than they care to count."
Unidentified man: "I've had enough hurricanes."
Berman: "But it could get even worse. According to a comprehensive study, hurricanes will become even more intense because of global warming -- the idea that greenhouse gases are heating the earth's atmosphere and oceans."
Tom Knutson, Geophysical Fluid Dynamics Lab Climate Modeler: "Those storms that do occur are going to have the potential to be significantly stronger in a warmer climate."
Berman: "Hurricanes get their strength from warm ocean water. Higher water temperatures mean more energy for the storms."
Knutson: "As a storm is moving across the ocean, it's evaporating water from the ocean's surface, and that's supplying the fuel for the storm."
Berman: "Tom Knutson is lead author of the study which used one of the world's most powerful computers to simulate 1,300 virtual storms. He found that within 80 years, the average hurricane strength will increase by half a category in the five-step scale of destructive power."
Robert Tuleya, Old Dominion University Center for Oceanography: "It could be the difference between, say, a roof staying on the house and the roof being ripped off."
Berman: "Average wind speed could jump 15 miles an hour, rainfall two inches and storm surge several feet."
Tuleya: "In our simulations, you end up with some of these really monster storms."
Berman: "The study says nothing about how global warming will affect the frequency of hurricanes, but the researchers say that is next on their agenda. The residents of Florida will be waiting. John Berman, ABC News, New York."

And here is the complete transcript of the July 15 story which concludes by dismissing the influence of global warming on the current hurricane season:

Elizabeth Vargas: "Another major storm is causing misery in the Caribbean. Tonight, Hurricane Emily has winds of 115 miles per hour and could threaten Texas by Tuesday. It is the fifth named Atlantic storm since June 1st. the first time since they began keeping records in 1851 that so many major storms have formed so early. So for our 'Closer Look' this evening, what's behind all this? And are more deadly hurricanes on the way? Here's ABC's Jeffrey Kofman."
Jeffrey Kofman: "Last week, Hurricane Dennis, now Hurricane Emily. July is supposed to be low season for hurricanes. But it seems just like peak season, late August, early September. And there are good reasons."
Stan Goldenberg, NOAA Meteorologist: "Really, what you have is you have just a combination of a lot of favorable factors hitting the Atlantic right now, setting up for a very, very active year, which has already really started now."
Kofman: "The first named storms of the season -- Arlene, Bret and Cindy -- had limited punch. Dennis and now Emily are different, born from storms blowing off the coast of Africa in an area meteorologists call the Tropical Box, where warm water acts like jet fuel for hurricanes. Usually, these waters stay cool until late August, but already this July, the entire area of the Atlantic where hurricanes form is two to four degrees warmer than normal."
Bruce Albrecht, University of Miami Meteorologist: "This time of the year, we don't expect to see hurricanes forming off systems that come off the African coast. And this year is an exception to that."
Kofman: "And then, there's the Bermuda high, a high-pressure system that is sitting over the north Atlantic. Right now, it stretches almost to American shores. Hurricanes can't penetrate it, so they are forced westward to the Caribbean, Florida and the Gulf. Even the wind patterns over the Atlantic this summer are helping the hurricanes thrive."
Goldberg: "Yes, we're seeing a lot in June, July so far. But, really, I would expect the worst is yet to come. We've got a lot of activity to go. This is going to be a very, very busy year."
Kofman: "Scientists say this is not because of global warming, it is simply a lot of cyclical climate patterns conspiring to create the perfect conditions for a long season of perfect storms. Jeffrey Kofman, ABC News, Miami."