Not all climate change is Climate Change

With the current drought in California, the experts seem to agree that it is within the range of natural variation that has been measured and experienced in the past. In other words, this specific drought isn’t being linked directly to climate change, though a great deal of the conversation surrounding this drought seems to be about whether or not it can be definitively proved that human beings have caused the climate change that is causing this drought.

One op-ed I read about this clearly illustrates what we typically get wrong when talking about climate and Climate Change. Here’s an excerpt:

Why should we care about what caused this drought, or for that matter, other extreme events like this winter’s severe cold over the Midwest or last year’s floods in Colorado? An accurate interpretation of the cause or causes can provide a preview of the future. It can help us understand whether the current experience is normal, or may instead foretell a new normal. The diagnosis is key to the prognosis. [emphasis mine]

Following this along a climate skeptic’s line of thinking, we can see that it is very easy to make an argument against anything that would ameliorate or react favorably to climate change, because this particular drought isn’t being tied directly to anthropogenic climate change. The argument goes like this:

This drought is caused by normal weather variations. Because this kind of issue is not caused by climate change, we do not have to make policies that relate to climate change. 

I don’t know more about climate than the climate analysts. The author of the above paragraph is Martin Hoerling, who studies climate extremes for the National Oceanic and Atmospheric Administration (there’s more from him, here). I also don’t think that most of the climate experts working on this issue are trying to discourage efforts to deal with climate change.

However, there’s a part of this that isn’t being talked about very much. We’re very interested in causation, but reaction?

What’s different this time, however, is that the demand for water has greatly increased in the state, and it may very well be that the current stress created by the failed rains is more severe than for similar rainfall deficits 40 years ago.

Regardless of the root cause of this particular California drought–which very well may be natural climate variation, not capital-C Climate Change–it seems that a great part of the struggle in dealing with the drought is due to increased demand for water. To my mind, this is what we should be focusing on as much as or more than the cause of the drought.

Whether it’s climate change or Climate Change, we do not have very resilient or adaptive human systems currently in place. President Obama’s science adviser, John Holdren, makes the following points about drought as it relates to climate change.

These four mechanisms [of climate change worsening drought] are:

  1. In a warming world, a larger fraction of total precipitation falls in downpours, which means a larger fraction is lost to storm runoff (as opposed to being absorbed in soil).
  2. In mountain regions that are warming, as most are, a larger fraction of precipitation falls as rain rather than as snow, which means lower stream flows in spring and summer.
  3. What snowpack there is melts earlier in a warming world, further reducing flows later in the year.
  4. Where temperatures are higher, losses of water from soil and reservoirs due to evaporation are likewise higher than they would otherwise be.

So, although there doesn’t seem to be definitive proof that this current drought situation is caused by climate change, it seems clear that Climate Change has the potential to make drought conditions more frequent and more severe. Further, continuing unsustainable practices of land and water management means that no matter what the cause of the drought, we are ill-prepared to deal with the ensuing situation.

My point here is that arguing over causation is not as essential as Hoerling makes it out to be in the first quoted section I’ve pasted here. Causation is an important aspect of research, especially for climate scientists. However, extending public debate about the causation of specific climate issues seems to focus on the baseline question of Do we need to worry? If the public take-away from this kind of event is that climate change is irrelevant to (all) climate since it cannot be directly held responsible for this specific drought, we’re endangering the possibility for positive change towards more sustainable use practices (such as water conservation).

If you’re interested in learning more about this drought, this is the best article I’ve found so far (more technical, but still accessible).

And just to be perfectly transparent, here’s my reading list as I went about writing this post:


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