Thursday, May 8, 2014

In the News: National Climate Assessment 2014

Earlier this week, the U.S. government released the National Climate Assessment (NCA), a hefty tome compiled by 300 experts in the field. This report presents a synthesis of the latest and greatest science on the issue of climate change in the United States, and was eagerly anticipated by those of us who fall into the green/ nature nerd/ environmentalist category. After admiring the report's slick website and appealing graphics, I scrolled through and excitedly began to read the report highlights... and then my eyes glazed over.

But wait... isn't this your "thing"? Don't you care about climate change?  Absolutely.  But truthfully, this report seems to be the same iteration of every other climate change report that I've seen in the past few years: climate change will affect our water supply and agriculture, threaten human health, lead to increased conflicts, cause species extinctions and range shifts, melt the Arctic, lead to increased extreme weather events, cause sea levels to rise and oceans to acidify, and hit hard economically.  These facts do not change from one climate report to another, and neither does the chilling conclusion: climate change is happening here and now, and we need to act immediately (actually, we needed to act yesterday, but better late than never...right...?).

One feature of the NCA that I was pleased to see is the option to click through region-by-region to learn how climate change is already affecting certain areas of the country, and what effects are predicted in the coming decades. I can't speak for everyone of course, but I've found that when someone communicates to me how a certain issue will impact me directly, I tend to start caring a little more about said issue.  Probably not the best attitude to have, but that's just human nature.  Perhaps if folks take the time to review the section of the NCA that is applicable to their own region, the urgency and grim effects of climate change will hit home, and action on climate change will ensue.  Or at least I can hope that it will.

Naturally, I scoured the section of the NCA focusing on the Northwest to find out what it had to say about the way climate change is affecting my home state of Washington. A local news station's erroneous conclusion that our region is not affected by climate change couldn't be further from the truth. The NCA report makes it clear that climate change is already taking hold of our region.

I found that the "Highlights" section of the report was just that - quick and to the point, with few statistics.  However, most people are unlikely to read through the detailed full report, so below I've attempted to expand on the "highlights" and include some of the statistics from the full version of the report. The report's four "key messages" and my thoughts thereon are as follows, for those of my fellow Northwesterners who may be interested:

Key Message #1: Water-Related Challenges

Climate change is expected to bring about changes in the timing and availability of water, especially in regard to water sources dependent on snowmelt. And these are not good changes.

Figure 21.2 NCA 2014 (Graph on the right is difficult to see, but the darker brown = decreased streamflow)

Already, snowpack in the Cascades has decreased 20% since 1950; spring snowmelt is occurring up to 30 days earlier; and summer streamflow has dropped as much as 15%.  What does this add up to? Less water available during the drier months (summer/fall) for the competing needs of drinking water, crop irrigation, migrating salmon, and production of hydroelectric power, among others. And these effects are only predicted to worsen as climate change progresses.  The report states that there is a "near 100% likelihood" that summer streamflow will be further reduced by the year 2050. When was the last time I read a scientific paper that said there was 100% chance of anything? Never. The authors aren't holding back when it comes to communicating the seriousness of this issue.

Also, if you think that the Pacific Northwest is rainy enough as it is, you aren't going to like this: by 2050, extreme daily precipitation is projected to increase up to 20%, and the number of days with greater than one inch of precipitation could increase 13% by 2070, leading to increased flooding and stormwater management concerns.

Key Message #2: Coastal Vulnerabilities

Rising sea levels and the increasingly acidic water of the Pacific Ocean pose a threat to coastal communities, infrastructure, and habitat.

Figure 21.3 NCA 2014
 Sea levels off the Northwest coast have risen eight inches since 1880, and are projected to rise an additional one to four feet by the year 2100. This increases erosion and potential flooding of coastal areas and beaches, and will also result in salty ocean water infiltrating fresh groundwater supplies.

Waters off the Northwest coast are among the most acidified in the world.  Ocean acidification has already hit oyster farmers hard, and threatens the survival countless other marine species. Increasing water temperatures have also altered the ranges, types, and abundance of marine species in coastal waters.

Key Message #3: Impacts on Forests

Warming temperatures threaten our forests with increased wildfires and outbreaks of tree diseases and harmful insects. Widespread tree die-offs are already documented and expected to increase.

Figure 21.7 NCA 2014
This section really hit me in the gut. If you have followed this blog for any length of time, you already know how precious our Pacific Northwest forests are to me.  Sadly, water deficits driven by climate change are anticipated to cause the annual area burned by wildfires to quadruple (to 2 million acres) versus the 1916-2007 period. 

Outbreaks of harmful insects such as the mountain pine beetle will also rise right along with the temperatures. These pesky insects have the capability to wipe out entire stands of pine trees.  The report does offer this consolation though... eventually, temperatures will warm up to the point where they "exceed the beetle's optimal limits," at which point the beetles should no longer threaten the forests. See... good news... it's going to feel like a furnace around here, and the trees will probably burn down anyway, but at least we'll reach a point where the beetles aren't a concern!

The Northwest climate is expected to reach such unfavorable conditions by late century that an estimated 21-38 current NW plant species will no longer be able to find habitat here. Subalpine forests and alpine ecosystems are projected to undergo complete conversion to other vegetation types by the 2080's.  The "evergreen" part of Washington is sure going to look different in the coming decades...

Key Message #4: Adapting Agriculture

Agricultural productivity in the Northwest will be threatened by soil erosion and water supply uncertainty.

We all love our Washington apples and wine, Idaho potatoes, and whatever produce Oregon is known for, but these, among hundreds of other crops, will be threatened by the changes in water supply brought on by climate change.  According to the report, the risk of water-short years for agriculture is expected to increase to 32% by 2020 and 77% by 2080.  Needless to say, this will have a tremendous impact on the region's economy and livelihood of the farmers.

The report does note that warmer temperatures, longer growing seasons, and increased atmospheric CO2 may produce an increase in crop yields, for a time.  However, these same conditions are also ripe for outbreaks of plant diseases, pests and insects, which could wipe out any possibility of greater crop yields.

Snoqualmie Valley - Lainey Piland photo

The NCA also includes sections on response strategies to deal with climate change.  The two main strategies are mitigation (taking steps to reduce or eliminate the carbon dioxide emissions that are causing climate change in the first place), and adaptation (planning for, and adapting to, climate change consequences that are already happening and/or are unavoidable).  I won't go into detail here on the response strategies, but they can be reviewed by clicking the link above.

So there we have it.  The National Climate Assessment 2014.  Really, the overall message isn't a new one, but the way in which it is presented appears to be effective. There is still much work to be done by our government--which is known for dragging its feet on the issue of climate change-- but at least, I am thankful that the current administration is making a statement and putting this information out there and making it available to everyone. 

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