What’s the New Climate Normal?

What’s the New Climate Normal?


On a state-by-state basis, the annual average minimum (left) and maximum (right) temperatures across the United States are warmer in the 1981-2010 Climate Normals than in the 1971-2000 version.
Credit: NOAA

The word "normal" has a different definition in climate science than in daily life. In the scientific sense, climate normal is defined as the average of the past 30 years of data about temperature, precipitation and other aspects of weather. Climate is what’s normal, what’s typical, what you’d expect.

Yet, we now have a new normal for climate. If you average the past 30 years of temperature data you will have a higher number of degrees than if you average an earlier 30 years of data. Climate is changing, which means normal is changing, at least in the scientific sense. We have a new baseline.

As Superstorm Sandy was headed for the East Coast of the US, NCAR scientist Kevin Trenberth explained Sandy’s relationship to climate in an op-ed stating that, “it is important to recognize that we have a “new normal,” whereby the environment in which all storms form is simply different than it was just a few decades ago.”

With the additional greenhouse gases we have added to the atmosphere, we have loaded the dice. Weather is not the same game, yet it is a part of climate as we know it today. In a few more decades we will have another new normal as climate continues to warm.

The word “normal” is used in many different contexts, and I wonder how the expression “new climate normal” will affect people’s perception of climate change.

In a speech after Superstorm Sandy had flooded lower Manhattan including the United Nations headquarters, U.N. Secretary-General Ban Ki-moon said that, “we all know the difficulties in attributing any single storm to climate change.  But we also know this: extreme weather due to climate change is the new normal.”

His use of the term “new normal” seemed to indicate that there are realities that we need to face, that we must take measures to be more resilient. Or, as UCAR Center for Science Education RETI teacher Kelly Ford put it, “new normal” means “get used to it”.  Our efforts to “get used to it” are important. We need to adapt to the new conditions, yet I wonder whether the term “new normal” will cause people to give up on trying to reduce the rate of climate warming. If a warmer climate is normal, then why stop it?

 “Normal” is also used to indicate that everything is fine.  For example, the subject of “new normal” came up yesterday when I was having a dental cleaning. (I know this example is a little far from climate change, but I think it relates.)

The hygienist was assessing the health of my gums with a numerical scale, proclaiming numbers as she prodded the gum by each tooth. All I understood of the scale was that numbers 1-3 were okay, and above three was bad. At one point she poked my gum and said “four!”

“Uh oh,” I responded, my mouth still wide open. While she is a strong advocate for flossing, the hygienist also tried to make me feel better about my four. “Some people think four is the new normal,” she said indicating, I suppose, that we are lowering the bar on healthy gums. I felt relieved. Part of my gum was still less healthy, but the word “normal” was comforting and I clung to it. If my gums are the new normal, then why floss?

Perhaps we are constantly assessing whether things are okay. Or perhaps we are not. We could be caught off-guard by a toothache or a superstorm. However, there are steps we can take to be more resilient and prevent future damage, to prevent rapid climate warming and tooth decay. We can address the new normal by taking steps to adapt to the new conditions while also preventing the situation from getting worse.

I, for one, resolve to floss.