It's not just about polar bears

I just sat down to have a quick look at some of the (too many) RSS feeds I subscribe to, and I clicked on ClimateArk.org, which is essentially an environmental news aggregator. Five headlines appeared in my Google Reader screen. They highlight one of the directions that seems more and more relevant to climate science and policy: regional impacts of climate change. As the entire planet warms slightly, there will be substantial, life-altering changes to some regions, while others will be largely unaffected. Well, at least not as directly affected as some. Understanding these regional variations and predicting where they will occur and estimating the impact of changes in the physical system to ecosystems and populations is an emerging science. Even with relatively well-understood effects, like decreasing snow cover and melting permafrost in the far north, have unknown consequences (like understanding how much methane will be released when the permafrost melts).

The articles that came up on ClimateArk.org show some additional examples. First, form the Senate Foreign Relations Committee held hearings about how climate change will impact national security. Essentially, this is an example of how regional climate change will amplify unstable political situations around the world by stressing food and water supplies, changing coastlines, and shifting weather patterns. Second, a study coming out of the University of Colorado and CIRES assesses the water supply in the Colorado River Basin, and the authors suggest that persistent drought associated with climate change could lead to severe water shortages in the basin, which supplies water to some 30,000,000 people. This article reminded me of Brian Fagan’s interesting book “The Great Warming,” which looked at the so-called Medieval Warm Period and the rise and fall of societies around the world. One of the take-home messages of that book was that a little warming isn’t too bad for a lot of societies, but persistent drought destroys them. The third news item that was sitting on the top of the ClimateArk.org feed was covered by two articles, and is about crops in California’s central valley. A UC Davis study finds there has been a decrease in the “chilling hours” that cropland experiences, and several important crops rely on this cold winter weather. I would venture to guess that this regional effect is partly due to land use change and partly due to global warming, but that is just a guess. The important thing is that this becomes a serious concern to the food supply for the whole country, and many other countries, not to mention that California’s economy had long depended on agriculture. If crops start to falter in California, it really could have a destabilizing effect on the national economy and will impact jobs (agriculture, packing, shipping) and food supply and prices.

It’s also worth noting that two of the above articles contain sentences that say something like, “climate change isn’t just about polar bears, it’s about security.” In the first it is national security and in the last food security.

Conflicting reports about Colorado snow pack?

Just last week I posted a link to an article saying the northern Colorado snow pack was slightly above the 30-year average, even though much of the state remains in drought conditions. Saturday, the same news source posted an article saying the state's snow pack is slightly below the 30-year average. 

So, what's the story? 

As of 1 March, the state-wide snow pack was above average for all the major basins. February was, however, quite dry, and lead to decreases in the percent of normal across all basins. [source: US Dept of Agriculture, Nat'l Resources Conservation Service] It is also notable that the dry conditions in early 2009 have made the snowpack much less than in 2008. The story from Friday, supposedly from GreeleyTribune.com (I can not find the article) specifically is about the 1 April report, though. 

Although the report from the USDA NRCS for 1 April does not appear to be available, the data is. Looking at the Basin reports, it is clear that the FortCollinsNow.com article from 1 April is misleading. Here are the relevant numbers:

CACHE LA POUDRE BASIN
BENNETT CREEK         83 64
BIG SOUTH             50 79
CAMERON PASS         105 108
CHAMBERS LAKE         74 72
DEADMAN HILL SNOTEL   92 99
HOURGLASS LAKE        69 64
JOE WRIGHT SNOTEL    100 110
LONG DRAW RESERVOIR   97 ****
RED FEATHER           91 94
Basin Totals          93% 95%
Number Courses         9  8
                   (LSWE = 108.5) (SWE = 93.3)
                   (LAST = 117.0) (AVG = 97.7)

Cameron pass is 108% of average, and 105% of last year (these numbers are as of today), just as the article reported. However, Joe Write Resevoir is just 110% of average, not the 112% reported. More importantly though, note that every other station in the Cache La Poudre Basin is below normal, some amazingly below normal. The basin as a whole is at 95% of normal, which is clearly below 100%. 

The Colorado state-wide snowpack stands at 96% of normal as of 1 April. This is the value given in the FortCollinsNow.com article from yesterday.

So to summarize, I think we've learned a couple of things. First, Colorado is, on average, below the 30-year mean snowpack. Second, there is large regional variability, and very large station-to-station variability. Third, we are reminded that news sources are not as reliable as they should be; the numbers in the article I linked to on Friday are a clear cherry-pick. Two spot measurements clearly do not reflect the overall situation in either the Cache La Poudre basin or state-wide. 

Northern Colorado has water!

Yes, according to a recent survey of mountain snow pack, northern Colorado is (slightly) above the 30-year average. I guess that means no water shortages this summer, right? Don't get too excited, Coloradoans, since almost the whole state is still in drought conditions according to the US Drought Monitor.