Seattle Times Glacier Disaster

The headline in this morning's Seattle Times had a lot of shock value.  Using huge type, the word DISASTROUS boomed a serious warning.   It about the Northwest glaciers.  Terrible things were happening to them and terrible things would happen to us, from lack of water to dead fish.

Now I probably should just ignore this story.  The Seattle Times has a reputation for hyped environmental stories and irresponsible headlines, from ocean acidification killing shellfish (not true, oyster harvests have been fine and clams have been abundant) to pollution causing a change in storm intensity (again, not substantiated by either observations or models).

But I can't help note that this article did not tell the whole story and gave such a myopic view that wrong conclusions could easily be inferred.  Let me give you the perspective lacking in the article .

The story deals with glacier loss in the North Cascades, and featured the work of Mauri Pelto, a glaciologist at a small (1000 student)  eastern U.S college (Nichols).  Dr. Pelto has been coming out to the North Cascades since the mid-1980s to survey some of its glaciers and has described a loss of glacier ice mass for the past few decades, with a particularly large loss this year.  He has been blogging about "disastrous" losses of glacial ice, and several newspapers, including the Seattle Times have picked it up, with the ST going full out with a huge headline.

So is there a disaster going on?   To evaluate this, let's make sure we know how to recognize a disaster by checking the dictionary.

So a disaster should be a sudden event that causes great damage.  Are the changes in the glaciers a recent change?  Can this be connected with a sudden surge of global warming caused by mankind?
Will the impacts be significant?  Let's find out.

The respected International Program on Climate Change (IPCC) has examined the retreat of glaciers across the planet.    As shown by a figure from one of their reports, the lengths of glaciers across the world have been generally shrinking since the late 1800s.

As described by the IPCC and in other work, the explanation is clear.  The earth started warming in the late 1800s as it came out of the multi-century Little Ice Age.     This warming is thought to be natural since mankind's impacts (e.g., from emissions of carbon dioxide) were small then.   The glaciers starting melting due to increasing global temperatures.  And with some variability, the warming has continued since that time.

But what about Northwest glaciers?  As with their global cousins, most have been melting since the late 1800s.   This is easy to demonstrate.

One of the most respected experts on such matters, Professor Steve Porter of the UW Quaternary Center, has this plot of the boundaries of Rainier's Nisqually glacier on his website.  A steady retreat since the mid-1800s.

Or to see all of Rainier's glaciers, here is a graphic of the glaciers on the entire mountain in various years:

Big retreat between 1898 and 1913, which continued to 1971. This retreat would have been of a natural origin.

 Kristina Thorneycroft of Portland State University has studied the glacial trend over the North Cascades (see figure), with her results showing that either for the North Cascades Park as a whole or the South Cascades glacier area in particular, the downward trend  f glacial mass has been going on for more tha a century.

I can show you a dozen more of these kinds of figures from other scientists, but the bottom line is clear:  the retreat of glaciers have been going on for more than a century.  It started before mankind could have been the cause.

We can secure more detail about the North Cascade glaciers based on the research completed by the National Park Service.   Here is a summary plot showing the cumulative changes in the amount of ice in some north Cascade glaciers from 1993 to 2011.  Very little change from 1993 to 2001, a decline during the warm years of 2001 to 2007, and then little change during subsequent cool years.  I am sure that their update of this plot in the future will show a big melt this year.

Until roughly 1970, the retreat of NW glaciers was mainly natural in origin (because the radiative effects of mankinds greenhouse gas emissions were small until that time).   During the past few decades, anthropogenic greenhouse gas emissions have undoubtedly made a contribution to the trend. This year we have had very little snowpack and with record warm temperatures, there has been melting of the glaciers.  But one year does not make a trend.  And as I have demonstrated in my previous blogs (with references), there is little reason to expect that next year will be similar or that humans are the cause of the extreme warm anomalies this year.

So the first part of the definition of a disaster....that it be sudden...is clearly busted. Glacial melting has been going on a long time and humans have not been the main cause of the glacial retreat for most of the time.

According to the definition of disaster, there should be great damage or loss of life.  Well, I don't think anyone is claiming there is loss of life from glacial melt.  But what about damage?   The main thing folks are talking about is stream flow and water resources..

Nearly all of the water used in the Northwest is NOT from glacier melt, but rather from winter  rainfall and snowpack melting during the summer.

A peer-reviewed paper by Schaner et al, (2012) looked at this issue.  Here is a map with their results for our area, showing the largest percentage of glacier melt to water supply in rivers for at least one month.  Grey (less than 5%), green (at least 5%), yellow (at least 10%), orange (at least 25%), red (at least 50%).    Most of Northwest is less than 10%.  And this is generally only for one or two months during the summer.  The rest of the year glaciers provide little water.

The North Cascades have the most glacier area of any place around here and NC Park did a study for the percentage of glacier runoff for the summer period (see below).  The numbers are a bit high because they also include the melting of seasonal snow accumulation on the glaciers. For Ross Lake (important for power generation), we are talking about roughly 5% during the warm season.  Stehekin  River, perhaps 8%.  Baker River roughly 12%, and only for the small Thunder Creek are we up to about 25% for the warm season.

No major urban or agricultural area in our state is dependent on glacier melt.   And even north Cascades areas only get a few percent of their annual water from it.  Bellingham, the nearest major city to the North Cascades area featured in the Seattle Times story has no water issues this year and has not even had metering for its residential users (they are finally putting meters on now because of State law).

So the bottom line is that the impacts of reduced glacial melt are generally small, with only a few exceptions.

So the second part of the definition of disaster is not met.  There is little impact.

Based on the above, I will let all of you decide whether the Seattle Times was being accurate and responsible in their Disastrous title.  You can guess how I feel.  No where in the article were readers given the long-term perspective.  Not one mention of the little ice age.  That the glacial melt has been going on for a long time. No where were the minor impacts of loss of some glacial melt noted.  It was painted as a crisis.  And that is simply not true.

And there is something else...although lower elevation glaciers are melting, higher level glaciers are stable and are expected to grow under global warming, which is predicted to bring more water to our region.

This year was an amazingly anomalous year, with record summer temperatures.  Melting is greater this year.   But folks need to be very careful about assuming it represents any kind of trend or serves as an indicator of what we will experience during the next few decades.  By the end of the century, anthropogenic global warming will be large over our region and there will be a serious loss of lower-elevation glaciers.  Summer glacial melt will be greatly reduced.   It won't be good.   Fish will suffer.  Water supplies will tighten in a few locations.  But it won't be a disaster or crisis.

Thunder Creek

______________________

What to do something to deal with global warming?

    If you are interested in learning about and helping the Washington State revenue-neutral carbon tax initiative, check out the CarbonWashington web site.  The need signatures for the initiative and financial support.    I strongly support this bipartisan effort.