[MCN] Our new climate isn't looking forest-friendly

[Lance Olsen]

The article: Noah D. Charney et al, Observed forest sensitivity to 
climate implies large changes in 21st century North American forest 
growth, Ecology Letters (2016).
DOI: 10.1111/ele.12650
http://onlinelibrary.wiley.com/doi/10.1111/ele.12650/abstract;jsessionid=FE48F403B6D88E2BDB6B40AD7BBDB8E2.f01t02

News release here (includes informative, at-a-glance map)
http://phys.org/news/2016-07-north-american-forests-climate.html

Excerpts from the release:

The most dramatic changes in projected forest growth rates were found 
in the interior West of the North American continent, with up to 75 
percent slower growth projected for trees in the southwestern U.S., 
along the Rockies, through interior Canada and Alaska.

"Many previous climate modeling studies counted on the boreal forests 
to save us from the climatic disaster by offsetting our emissions, 
but we don't' see any greening in our results," said Valerie Trouet, 
an associate professor in the LTRR. "Instead, we see browning. The 
positive influence warmer temperatures are believed to have on boreal 
forests-we don't see that at all."

"In Alaska, for example, where trees have been projected to respond 
positively to warming temperatures under the boreal greening effect, 
we see that trees are now responding negatively instead," Evans said. 
"Trees in very high latitudes are limited by cold temperatures, so 
yes, in warmer years they grow more, but there is a tipping point, 
and once they go past that, a warmer climate becomes a bad thing 
instead of a good thing."

"There is a critical and potentially detrimental feedback loop going 
on here," Charney said. "When the growth rate of trees slows down in 
response to environmental stressors such as cold or drought, they can 
get by for a few years, but over time, they deplete their resources 
and are much more susceptible to additional stressors, such as damage 
by fire or a big drought or insect outbreaks. Year after year of slow 
growth therefore means forests become less and less resilient."

As a result, a forest can go from being a climate asset to a carbon 
producer very quickly.
"It's like a thermostat gone bad," Evans said. "Forests act as a 
carbon sink by taking carbon dioxide out of atmosphere, but the more 
the climate is warming, the slower the trees are growing, the less 
carbon they suck up, the faster the climate is changing."

Read more at: 
http://phys.org/news/2016-07-north-american-forests-climate.html#jCp
-- 
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"Increasingly, gaining access to farmland is part of a broader 
corporate strategy to profit from carbon markets, mineral resources, 
water resources, seeds, soil and environmental services."

https://www.grain.org/article/entries/5492-the-global-farmland-grab-in-2016-how-big-how-bad
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"When asked why climate change is so politically charged, John 
Holden, director of the White House Office of Science and Technology, 
tells us: "I think the most fundamental reason is this misperception 
that being in favour of addressing the climate change challenge is to 
be against jobs and the economy."

http://www.aljazeera.com/programmes/techknow/2016/07/politics-climate-change-united-states-160714105644450.html






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