Over the past 20 years, more than 4 trillion tons of ice from Greenland and Antarctica has melted and flowed into the oceans, raising sea levels by 11 mm. The U.S. and world are experiencing some of the warmest years on record. Climate change is exacerbating bark beetle outbreaks by speeding up their reproductive cycles and reducing cold-induced mortality through higher temperatures and drought. By 2050, climate changes could reduce U.S. GDP by over $1 trillion due to impacts on precipitation patterns. Climate change is also a driver of displacement as it undermines livelihoods. Species extinction risks increase substantially above 1.5-2.5°C of warming. The Earth's biosphere may

1. People, Energy, and the Environment

4. More than 4 trillion tons of ice from
Greenland and Antarctica has melted in
the past 20 years and flowed into the
oceans, pushing up sea levels 11 mm.
Shepherd et al. (Dec 2012). A
Reconciled Estimate of Ice-Sheet Mass
Balance. Science.

8. The U.S. is about to register the warmest year on
record in the lower 48 states, and the world its
ninth-hottest, a United Nations agency said in
a report, adding new urgency to the quest to
control global warming.
Two-thirds of the U.S. states suffered drought
this year, while heat waves hit across Europe
and in Morocco, Jordan, China and Russia, the
World Meteorological Organization said in a
report released in Doha, where UN climate
talks began this week. It noted Arctic sea ice
shrank to its smallest on record.
“The alarming rate of its melt this year highlighted
the far reaching changes taking place on
Earth’s oceans and biosphere,” WMO
Secretary-General Michel Jarraud said in a
statement. “Climate change is taking place
before our eyes and will continue to do so as a
result of the concentrations of greenhouse
gases in the atmosphere, which have risen
constantly and again reached new records.”
Guardian Environmental News Online

9. Climate change is one factor that appears to be
driving at least some of the current bark beetle
outbreaks. Temperature influences everything in a
bark beetle’s life, from the number of eggs laid by a
single female beetle, to the beetles’ ability to
disperse to new host trees, to individuals’ over-
winter survival and developmental timing. Elevated
temperatures associated with climate
change, particularly when there are consecutive
warm years, can speed up reproductive cycles and
reduce cold-induced mortality. Shifts in precipitation
patterns and associated drought can also influence
bark beetle outbreak dynamics by weakening trees
and making them more susceptible to bark beetle
attacks.
U.S. Forest Service
http://www.fs.fed.us/ccrc/topics/bark-beetles.shtml

10. This figure shows the estimated reduction in the U.S. GDP over the period 2010 to 2050
from changes in precipitation, an economically important climatic feature. The values on
the solid red line represent the total cost over the 40-year period – placing a 50%
probability on the loss of $1.1 trillion – the equivalent of ~7 million jobs. Note how fast
the losses accelerate at the lower probabilities. The dashed lines represent the
uncertainty of the best-estimate exceedance-probability values. For any given point on
the best-estimate line, it is highly likely (.95 statistical probability) that the impact will lie
somewhere between the corresponding values on the enveloping dashed lines based on
projections with available data.

11. Antonio Guterres, the UN high commissioner for refugees, told the Guardian:
"Climate change is today one of the main drivers of forced displacement, both directly
through impact on environment - not allowing people to live any more in the areas
where they were traditionally living - and as a trigger of extreme poverty and conflict."

12. “Climate change is likely to lead to some
irreversible impacts on biodiversity. There is
medium confidence that approximately 20%–
30% of species assessed so far are likely to be
at increased risk of extinction if increases in
global average warming exceed 1.5–2.5
ºC, relative to 1980–99.”
Nobel Lecture by R. K. Pachauri, Chairman of
the Intergovernmental Panel on Climate
Change (IPCC), Oslo, 10 December 2007.

13. “As global average temperature exceeds
about 3.5 ºC, model projections suggest
significant extinctions (40%–70% of
species assessed) around the globe. These
changes, if they were to occur would have
serious effects on the sustainability of
several ecosystems and the services they
provide to human society.”
Nobel Lecture by R. K. Pachauri, Chairman
of the Intergovernmental Panel on Climate
Change (IPCC), Oslo, 10 December 2007.
“Localized ecological systems are known to
shift abruptly and irreversibly from one state to
another when they are forced across critical
thresholds. Here we review evidence that the
global ecosystem as a whole can react in the
same way and is approaching a planetary-scale
critical transition as a result of human
influence.”
Barnosky, A. et al. Approaching a state shift in
Earth’s biosphere.
Nature 486, 52–58 (07 June 2012)

14. Let’s talk.