In a segment on the causes of 2011’s extreme weather yesterday, CBS Nightly News completely ignored the influence of global warming pollution. The piece, reported by correspondent Ben Tracy, discussed the historic dust storm in Arizona, the record drought in the Southwest, and other floods, storms, and fires that are on track to make 2011 the most expensive year for climate disasters in U.S. history, even before hurricane season began.
Tracy, assigned to “look into why” there’s been so much violent weather, ascribed the “freak weather” entirely to mesoscale phenomena: La Niña, a “stronger than normal jet stream pattern,” and “warm water from the Gulf of Mexico”:
The dust storm is the latest freak weather phenomenon in a string of strange weather events. Drought in the southwest has fueled wildfires in three states, but in the western mountains there was so much moisture this winter the snow is still there. A lingering snow pack that hasn’t been seen for 15 years. That snow and record rains here in California were caused in large part by La Niña, cooler water temperatures in the Pacific that change weather patterns. That helped end California’s three-year drought. But la Niña was followed this spring by a stronger than normal jet stream pattern, creating winds that collided with warm water from the Gulf of Mexico, causing severe storms across the southern US, that led to all those tornadoes and record flooding.
Blaming La Niña for extreme precipitation in California is somewhat bizarre, since it is generally associated with drought in California. What is best said is that the weather extremes of 2010–2011 took place at the same time as La Niña conditions in the Pacific, so whatever underlying physical conditions exist must necessarily allow for both. Saying that La Niña “caused in large part” the record rains in California is a failure to accurately describe how our climate system works.
The weather expert in the piece, Jan Null, is a masters-degree expert on microclimates and heat deaths, not global climate, which may explain why the influence of climate change was not discussed.
In reality, the meteorological phenomena discussed by CBS News — the wildfires, droughts, floods, storms, jet stream pattern, La Niña, the warm Gulf water — are all ones that scientists know are influenced by global warming pollution. With hundreds of billions of tons of greenhouse pollution in the atmosphere, everyday weather is more intense, more unstable, and over all hotter. Regionally, the Southwest is getting drier and the Midwest wetter, while extreme precipitation becomes much more frequent. The oceans are warming significantly, and the jet stream is moving in response to the changed climate. Historically extreme weather is now the norm because of man’s reckless abuse of the atmosphere.
“It is irresponsible not to mention climate change,” Dr. Kevin Trenberth, one of the nation’s top climatologists, has told ThinkProgress about reporting on current extreme weather. Yesterday’s CBS News report was, quite simply, irresponsible.
SCOTT PELLEY: By far, the most awe-inspiring pictures we’ve seen this week came from Phoenix, Arizona, where a cloud of dust seemed to swallow up the entire city last evening. Flights were grounded, drivers couldn’t see more than a few feet in front of their cars. Folks who live in phoenix are calling it the mother of all dust storms. We’ve been hit by a lot of violent weather this year, and we asked Ben Tracy to look into why.
BEN TRACY: This is a legitimate haboob, or dust storm. The giant wall of dust that swept into Phoenix was bigger than most, a mile high and packing at least 60 mile per hour winds.
EYEWITNESS: We thought it was a cloud. then we got into it and it was just black.
TRACY: The dust began to gather near Tucson where it hasn’t rained in three months. By the time it hit Phoenix, it dwarfed the city. Larger than anything seen in 100 years. The dust storm is the latest freak weather phenomenon in a string of strange weather events. Drought in the southwest has fueled wildfires in three states, but in the western mountains there was so much moisture this winter the snow is still there. A lingering snow pack that hasn’t been seen for 15 years. That snow and record rains here in California were caused in large part by La Niña, cooler water temperatures in the Pacific that change weather patterns. That helped end California’s three-year drought. But la Niña was followed this spring by a stronger than normal jet stream pattern, creating winds that collided with warm water from the Gulf of Mexico, causing severe storms across the southern US, that led to all those tornadoes and record flooding. Meteorologist Jan Null studies weather patterns.
NULL: Whenever the atmosphere stays in a persistent pattern for an extended period of time we will get these weather events.
TRACY: And the weather may seem worse than normal because many of the storms have hit heavily populated areas. Chicago buried in record snowfall, Memphis flooded, large parts of Joplin, Missouri destroyed.
NULL: There’s more damage, more fatalities, and that makes it noteworthy.
TRACY: In fact, in an average year weather related damage would total about 6 billion at this point. In 2011 we have already hit 32 billion, the most expensive since they began tracking it 30 years ago. Ben Tracy, CBS News, Los Angeles.
PELLEY: We were talking in the newsroom about the weather today and we noticed this from the National Oceanic and Atmospheric Administration. So far this year there have been eight weather disasters in the U.S., blizzards, tornadoes, floods, wildfires, that did at least $1 billion damage each. and hurricane season is just beginning.
In a conversation with ThinkProgress, Jan Null said he thought the segment’s avoidance of global warming was “appropriate,” although he made sure to emphasize that he concurs with the IPCC on the existence and threat of global warming. Null’s hypothesis was that individual extreme weather events should only be looked at in the context of a long-term trend. His argument was an example of the error Trenberth warned against this January, when he said that “the null hypothesis should be that all weather events are affected by global warming rather than the inane statements along the lines of ‘of course we cannot attribute any particular weather event to global warming.’”