In December 2008 the Washington Post reported that AT&T and DuPont planned to lay off a combined 14,500 employees. The lead of the story said: “Need more proof that the recession is real? An onslaught of grim unemployment and layoff reports yesterday should dispel any lingering doubts.”

Was the recession the only force behind these job cuts? No. Other variables would be needed to explain why the layoffs were hitting these specific companies, at this time, and at this scale.  But the recession was the obvious background condition, the broader context that could not go unmentioned in a proper news report on the layoffs, and there was no hand-wringing about drawing the connection. The article didn't caution that “No single bankruptcy or job cut can be definitively blamed on the recession.” No one waited for a computer model to precisely sort the causes of these layoffs. No one tracked down a contrarian to point out that layoffs happened long before the recession and that, in fact, such-and-such a company somewhere is hiring.

Which brings me to the massive heat wave that we're now emerging from. Scientific observation and analysis have established that human-induced climate change makes extreme heat events more common. But when heat waves hit, many reporters hesitate to mention climate change without appending disclaimers of the sort that you don't see on other beats.

In part, this likely reflects the success of the right wing in politicizing climate science and making journalists weary of touching upon a “controversial” issue.  But there may also be some genuine confusion arising from the argument most recently made by conservative columnist George Will on ABC's This Week. We shouldn't draw connections between the recent heat wave and climate change, Will said, because during winter cold snaps, climate advocates are the ones insisting that “There's a difference between the weather and the climate”:

Will's argument is that it's hypocritical for those concerned about climate change to trumpet weather events in the summer and downplay them in the winter. Foreign Policy writer Joshua Keating said something similar: “The public might be forgiven for wondering if the mantra 'weather is not climate' only applies when the weather is politically inconvenient for the person discussing it.” On the surface, there seems to be some logic to their statements. But in fact, there's a false equivalence embedded in this argument.

Here's the problem: “Weather is not climate” is a bad mantra, for the same reason that “Did climate change cause the heat wave?” is a bad question. In reality, weather is the data that, over time, reveal the climate. When someone asks if climate change caused a weather event, they are wrongly implying that the climate is an agent acting on a separate subject. But there are no weather events that are taking place outside the context of a changing climate, and as German climatologists Dim Coumou and Stefan Rahmstorf have said, “Attribution is not a 'yes or no' issue as the media might prefer. It's an issue of probability.”

We know human activities - burning fossil fuels, deforestation -- are shifting the average conditions. We don't always know exactly where and how that change shows up in weather (each type of weather extreme must be examined individually), but there is substantial evidence that climate change amplifies heat extremes. “Of all the different extreme events that can happen, the partial attribution of heat waves to ongoing climate change is one of the easier connections,” according to NASA climatologist Gavin Schmidt. It's this body of research showing long-term trends that makes it valid to link climate change and weather during heat waves but question the link for cold snaps.  Or, as Penn State's Michael Mann told Keating: "It's OK to talk about [weather] events when you discuss them in a proper scientific context."

When climate advocates say “weather is not climate” during the winter, they are trying to communicate that weather variability doesn't stop just because the planet is heating up on average. It's crucial to note that they are saying this in response to those who claim a snowstorm or a cold snap refutes global warming. When you're trying to overturn a theory that is based on long-term data, a single storm or weather event just won't do. The burden of proof is higher. A cold snap doesn't tell us much about climate, but a whole bunch of them would over time. The trends just aren't going in that direction.

Back to the recession analogy. Imagine if, in 2009, President Obama spotlighted a company that was thriving to argue that the recession was over. Such a statement would not be taken seriously anywhere. Why? Because of the broader context -- because of what we knew about the trends in employment, GDP, investment spending. By the same token, we know that by warming the climate, we're making heat extremes more probable, and when we bring up climate change during a heat wave, it's not to say that a specific heat wave is evidence of climate change -- we have plenty of evidence in the long-term trends -- it's to say "this is what global warming looks like." The alternative, refusing to recognize the symptoms of a disease we know we have, isn't a smart approach, and it's not good journalism.