Using the very same expert the CBS Evening News cited on Monday, Wednesday's NBC Nightly News made -- as its second story of the night -- the case that the current heat wave can be blamed on global warming. Anchor Brian Williams set up the piece by ruminating about how “you hear a lot of people saying it didn't used to be like this, didn't used to be this hot, and because of global warming we've done this to ourselves.” Reporter Tom Costello asked: “So is our current heat wave a symptom of global warming?" Jay Gulledge of the self-interested Pew Center on Climate Change confirmed “this heat wave” is “completely consistent with what we expect to become more common as a result of global warming,” before Costello noted there have been heat waves in the past, but insisted that “experts say our current heat wave is unique."
Costello soon cautioned that “scientists want to see whether this heat wave is part of a pattern of longer more intense heat waves before declaring it all part of a bigger global warming phenomenon.” Costello concluded, however, without any doubt, as he referred to “the concern that in the coming decades 100 degrees may be the new summertime norm.” (Transcript and more follows)
On the July 31 CBS Evening News, a story from reporter Bob Orr featured this soundbite from Gulledge: “Things are getting hotter and climate scientists definitely say that the average global temperature is getting hotter because of global warming.” Orr elaborated, without any counterpoint: “Gulledge says there's no longer any serious debate. Glaciers are melting, the oceans are warming, and it seems relentless rains alternate with droughts on an increasingly regular basis. Taken together it all adds up to global warming.”
Today show weather reader Al Roker was a lot less certain Wednesday morning than Orr or NBC colleague Costello (see NewsBusters item by Geoff Dickens), telling Matt Lauer that the current heat wave “is not unusual” and it "doesn't support nor negate global warming." The exchange, as the two stood by a weather map:
Matt Lauer: "You hear people put up with the heat and then they say global warming. This is global warming. What do you think?"
Al Roker: "We get heat waves. This is not unusual. It's been five years since we've had one of this magnitude but it happens, it doesn't support nor negate global warming."
The MRC's Brad Wilmouth corrected the closed-captioning against the video for the August 2 NBC Nightly News story. Brian Williams introduced it:
"This heat wave has been so punishing, so widespread, and has lasted so long, you hear a lot of people saying it didn't used to be like this, didn't used to be this hot, and because of global warming we've done this to ourselves. But is that indeed the case? NBC's Tom Costello has a 'Reality Check.'"
Tom Costello began, with his list on screen:
"The debate over global warming has been raging for years. But here's what most scientists say is certain: The earth is warming, 1.4 degrees Fahrenheit since 1920; the icecaps are melting and sea levels are rising; 10 of the last 12 years were the warmest since 1850; and the first six months of 2006 were the hottest on record. So is our current heat wave a symptom of global warming?"
Jay Gulledge, Pew Climate Change Center: "This heat wave and other extreme events we've seen in recent years are completely consistent with what we expect to become more common as a result of global warming, even though we can't be definitive on any single event."
Costello: "We've had heat waves before. The worst was in the 1930s -- 50 million acres turned to dust. In 1972, 891 people died in New York over a 14-day stretch. And in 1995, 733 people died in record heat in Chicago. But experts say our current heat wave is unique."
Dennis Feltgen, National Weather Service meteorologist: "So far, we've had about 80 daily high temperature records broken, and in addition, in the month of July, there were over 50 all-time records for the month of July broken."
Costello: "But scientists want to see whether this heat wave is part of a pattern of longer more intense heat waves before declaring it all part of a bigger global warming phenomenon. Still, the movement to curb greenhouse gases is gaining traction, with 22 cities worldwide signing on to former President Clinton's initiative to cut CO2 emissions."
Bill Clinton, on Tuesday: "We have to use less energy and find cleaner sources."
Costello: "The concern, that in the coming decades, 100 degrees may be the new summertime norm. Tom Costello, NBC News, Washington."
As for scientific certainty, in a July 13 report (PDF of it) for the Competitive Enterprise Institute, “Global Warming FAQ: What Every Citizen Needs to Know About Global Warming,” Iain Murray laid out some basic facts. An excerpt:
Q: Isn’t there a scientific consensus that global warming is real and bad for us?
A: There is no “scientific consensus” that global warming will cause damaging climate change. Claims that there is such a consensus mischaracterize the scientific research of bodies like the United Nations Intergovernmental Panel on Climate Change (IPCC) and the U.S. National Academy of Sciences (NAS).
Q: What do scientists agree on?
A: Scientists do agree that: 1) global average temperature is about 0.6̊Celsius—or just over 1̊ Fahrenheit—higher than it was a century ago; 2) atmospheric levels of carbon dioxide (CO2) have risen by about 30 percent over the past 200 years; and 3) carbon dioxide, like water vapor, is a greenhouse gas whose increase is likely to warm the Earth’s atmosphere.
Q: Doesn’t this mean we should be worried?
A: As Richard Lindzen of MIT summarized it in The Wall Street Journal, “These claims are true. However, what the public fails to grasp is that the claims neither constitute support for alarm nor establish man’s responsibility for the small amount of warming that has occurred. In fact, those who make the most outlandish claims of alarm are actually demonstrating skepticism of the very science they say supports them. It isn’t just that the alarmists are trumpeting model results that we know must be wrong. It is that they are trumpeting catastrophes that couldn’t happen even if the models were right as justifying costly policies to try to prevent global warming.”
Q: What don’t scientists know yet?
A: Scientists do not agree on whether: 1) we know enough to ascribe past temperature changes to carbon dioxide levels; 2) we have enough data to confidently predict future temperature levels; and 3) at what level temperature change might be more damaging than beneficial to life on Earth.
Q: Didn’t the National Academy of Sciences say greenhouse gases cause global warming?
A: The National Academy of Sciences reported in 2001 that, “Because of the large and still uncertain level of natural variability inherent in the climate record and the uncertainties in the time histories of the various forcing agents…a causal linkage between the buildup of greenhouse gases in the atmosphere and the observed climate changes during the 20th century cannot be unequivocally established.” It also noted that 20 years’ worth of data is not long enough to estimate long-term trends.
Q: Hasn’t the Earth warmed precipitously over the past 100 years?
A: The temperature rise of 0.6̊C over the last century is at the bottom end of what climate models suggest should have happened. This suggests that either the climate is less sensitive to greenhouse gases than previously thought or that some unknown factor is depressing the temperature....