Consequences of Global Warming

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Consequences of Global Warming
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Some Current Consequences of Global Warming

• More Severe Heat Waves of Greater Duration
• Sea-level Rise and Ocean Acidification
• Glacier, Ice Sheet and Permafrost Melting
• Spreading Disease
• Plant and Animal Range Shifts Plus Extinctions
• Coral Reef Degradation
• More Severe and Frequent Weather Events
• More Severe and Frequent Flooding
• More Severe Droughts and Fires

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The Melting Earth
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Mountain Glaciers

• Over 95 of mountain glaciers are shrinking

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Glacial Mass Decrease from 1980 to 2004
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Melting Glaciers
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Rongbuk Glacier
Rongbuk glacier in 1968 (top) and 2007. The
largest glacier on Mount Everests northern
slopes feeds Rongbuk River.
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Mt. Kilimanjaro Glacier Loss
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Two Ice Sheets
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The Arctic
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Projected Temperature Change from 1990s to 2090s
(left) and Projected August Precipitation change
from 1980-1999 to 2070-2089 (right)
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Decline in the Arctic WINTER Sea Ice
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Arctic Summer Sea Ice Record Minimum (2007)
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The Worst Scenarios of the IPCC Underestimated
the Amount of Summer Sea Ice Decline
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Computer Model Simulation vs. Observed Decline of
Arctic Summer Sea Ice
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Arctic sea ice area at summer minimum.
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Age of Artic Sea Ice is Decreasing
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How Will the Polar Bears Fare Under Global
Warming?
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Greenland Melting (1992-2005)(Volume loss (2005)
240 km3 per year)
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Greenland Total Melt Area 2007 value exceeds
last maximum by 10
Konrad Steffen and Russell Huff, CIRES,
University of Colorado at Boulder
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Greenland Ice Sheet Melting
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Greenland Ice Sheet Instability
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Jakobshavn Glacier Contributing to Sea Level Rise
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Decline in the Area of Arctic Permafrost
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Projected Temperature Increase and Permafrost
Declineby the 2090s
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Melting Permafrost in Siberia (Siberian CO2
equivalent release from land was 235 million
metric tons per year in 2006)
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Accelerated Permafrost Melting

• The 2007 Arctic warming that caused the rapid and
  extensive sea ice decline accelerated the melting
  of permafrost. The accelerated warming extends up
  to 1500 km inland.
• If the recent trend in sea ice loss continues it
  may triple Arctic warming, causing large
  emissions of carbon dioxide and methane from the
  tundra.
• Simulated western Arctic land warming trends
  during rapid sea ice loss are 3.5 times greater
  than predicted 21st century climate-change
  trends.
• This could lead to a non-linear catastrophic
  warming.

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Methane Hydrate A Wake-up Call
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Methane Hydrate Ice Burns
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The Methane Hydrate Danger 1

• The frozen Arctic continental shelf off Siberia
  has started to thaw and release long-stored
  methane gas. The consequence could be an
  unstoppable near- to long-term catastrophic
  warming of the Earth.
• In this region the carbon content of the methane
  hydrates is estimated at 540 billion metric tons,
  or the CO2 equivalent of 1.98 trillion metric
  tons.
• Methane hydrate in the shelfs sediments is
  perilously close to thawing. Three to 12 km from
  the coast the ocean sediment temperature is just
  below freezing at -1 to -1.5 C. Permafrost on
  land is as cold as -12.4 C.

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The Methane Hydrate Danger 2

• The permafrost has grown porous and is becoming
  unstable. The shelf has already become a source
  of methane passing into the atmosphere. If this
  Siberian permafrost-seal thaws completely and all
  the stored gas escapes, the methane content of
  the planet's atmosphere would increase
  twelve-fold leading to a catastrophic rise in
  temperature.
• The Arctic Ocean is getting warmer as the summer
  sea ice continues to recede and the ocean becomes
  ice-free for extended periods. This will probably
  result in the temperature of the continental
  shelf sediments rising above freezing, releasing
  vast quantities of methane to the atmosphere.

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Warming of the Arctic Ocean 2000 to 2007
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Methane Beginning to Increase After 8 Years of
Stability

• During the past 8 years the methane abundance has
  been relatively stable due to industrial changes
  in Russia, changes in the methods of rice
  farming, and methane capture from landfill sites.
• In 2007 the world methane abundance increased
  0.5.
• Based on carbon isotope analyses the methane is
  of biogenic origin.
• The source is probably the release from melting
  permafrost, and the Siberian Arctic continental
  slope methane hydrates.
• We may now be entering a non-linear climate
  response.