Chapter 2 2.pdf · Chapter 2 •Changes in Sea ... Skeptical Science(2010) 14. Chapter 2

Chapter 2

• Changes in Sea Level

• Melting Cryosphere

• Atmospheric Changes

• Summary

• Ice is melting faster (sea ice, glaciers, ice sheets, snow)• Sea level is rising• More ocean heat content• More intense rainfall• More severe drought• Fewer frosts• More heat waves• Spring is arriving earlier

IPCC (2013)

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Chapter 2




• Summary

The Evidence of Climate Change(NASA link)

• More drought• Hotter days/nights increasing• Colder days/nights decreasing• Heavier precipitation events• Stronger Hurricanes

IPCC (2013)

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http://climate.nasa.gov/keyIndicators/

Chapter 2




• Summary

Web Alert:Modern Day Climate Change

&Global Warming: A Sea Change

Sea levels rise from thermal expansion and land-ice melt

Warmer water molecules move faster so they expand

Ice on land melts and the water flows into oceans

Sato & Hansen (2010)

3

http://www2.sunysuffolk.edu/mandias/global_warming/modern_day_climate_change.html

http://profmandia.wordpress.com/2010/06/21/global-warming-a-sea-change/

Chapter 2




• Summary

Along shallow coastal locations such as the eastern coast of the US, vertical sea level rise corresponds to much larger horizontal movement of water inland.

Kitchen (2013)

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Chapter 2




• Summary

Video: Climate Change & Sea Level Rise

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http://youtu.be/kffsux-ifKk



Chapter 2




• Summary

Web Alert:

Surging Seas Sea Level Rise Analysis

Mapping Areas Potentially Impacted by Sea Level Rise

Choose a location and map impact of future sea level rise

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http://sealevel.climatecentral.org/

http://www.geo.arizona.edu/dgesl/research/other/climate_change_and_sea_level/mapping_slr/mapping_slr.htm

Chapter 2




• Summary

Video: Expecting the Unexpected: Abrupt Climate Change

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http://www.yaleclimatemediaforum.org/2014/02/abrupt-climate-change-focus-of-new-yale-forum-video/

Chapter 2




• Summary

Video: Stephen Colbert’s The Word: Sink or Swim

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http://www.cc.com/video-clips/w6itwj/the-colbert-report-the-word---sink-or-swim



Chapter 2




• Summary


• Arctic sea ice is decreasing in

• Extent (Area)

• Thickness (Older, thicker ice decreasing)

• Volume

Click for most recent image

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http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/

Chapter 2




• Summary



• Extent (Area)


• Volume


2012 set new record minimum sea ice extent

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http://nsidc.org/arcticseaicenews/

Chapter 2




• Summary



• Extent (Area)


• Volume

UK Hadley Center

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Chapter 2




• Summary

Video: A New Climate State: Arctic Sea Ice 2012

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http://www.youtube.com/watch?v=ZYaubXBfVqo&feature=youtu.be



Chapter 2




• Summary

Web Alert:

Modern Day Climate Change

• Rate of ice loss in Greenland has more than doubled over the 11 year period since gravity measurements began


Skeptical Science(2011)

Wahr (2014)16 9 8 7 6 5 4 3 2 1 0 1 2 3 4 5

GRACE Rate of Mass Change

Feb 2003 Feb 2007.

cm/yr water thickness equivalent

Feb 2003 Jan 2014.

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http://psc.apl.washington.edu/ArcticSeaiceVolume/images/BPIOMASIceVolumeAnomalyCurrent.png

Chapter 2




• Summary


• Antarctica losing land ice, the ice loss is accelerating at a rate of 26 Gigatonnes/yr2

• The last time Antarctica was ice free sea levels were more than 70 meters (> 200 ft) higher than present

• East Antarctic Ice Sheet (EAIS) is fairly stable

• West Antarctic Ice Sheet (WAIS) is unstable and collapse could raise sea levels 5-6 m (>15 feet)

• Antarctic Peninsula very unstable

Skeptical Science(2010)

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Chapter 2




• Summary

Video: One Vid to Rule Them All, Part 2

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http://climatecrocks.com/2014/06/03/one-vid-to-rule-them-all-part-2/



Chapter 2




• Summary

• Since 1900 the extent of permafrost has decreased by 15% during the warm season

• Decreased snow cover has exposed more permafrost to warmer temperatures

• Methane trapped in frozen ground is being released as ground melts. Methane is a powerful but shorter-term GHG (20x CO2, lasts for 9-15 years

• Positive feedback results

UNEP/GRID (2007)

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Chapter 2




• Summary

Video: Hunting for methane with Katey Walter Anthony

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https://www.youtube.com/watch?v=YegdEOSQotE



Chapter 2




• Summary

Video: Permafrost: The Tipping Time Bomb

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http://climatecrocks.com/2013/02/28/new-video-permafrost-the-tipping-time-bomb/



Chapter 2




• Summary


• 90-95% of worldwide glaciers are retreating (a few are

gaining).

• 27% of sea level rise due to melting glaciers

World Glacier Monitoring Service (2011)

Skeptical Science (2010) 19


Chapter 2




• Summary


• Droughts are increasing due to more evaporation in a

warmer world

IPCC (2007)

Diffenbaugh & Ashfaq (2010)

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Chapter 2




• Summary

• Many regions in the world, including the U.S., are

forecast to have severe drought conditions in the next

two decades.

Dai (2010)

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Chapter 2




• Summary

• IPCC reports that intense rain events have increased in frequency during the last 50 years and human-induced global warming most likely contributed to the trend.

Pakistan devastated by massive flood, July 2010

Wikipedia (2010)

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Chapter 2




• Summary

• In the US and worldwide, extreme precipitation events are occurring more frequently in regions that are typically wet.

• Increased flooding is a direct result.

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Chapter 2




• Summary


Hurricane Katrina (NOAA, 2005)

• Greenhouse warming will cause stronger storms, with

intensity increases of 2–11% by 2100

• Possible decreases in frequency of tropical cyclones,

by 6–34%

• Substantial increases in the frequency of the most

intense cyclones

• Increases of the order of 20% in the rainfall rate within

100 km of the storm center

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Chapter 2




• Summary


Tropical cyclones in a warmer world (Pliocence)Federov, Brierley, & Emanuel (2010)

• According to NCDC, the destructive power of hurricanes has generally increased since the mid-1970s, when the period of the most rapid increase in global ocean and land temperatures began.

• By 2100, the climate is expected to warm 5 oC to 6 oC or more above pre-IR values. During the Pliocene, about 2.5 to 5 million years ago, CO2 levels were comparable to today's levels (near 400 ppm) and the climate was about 3 oC to 5 oC warmer than pre-IR. Geographically, the Earth was also very similar to today so the Pliocene offers a glimpse of what the world may look like by the year 2100.

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http://en.wikipedia.org/wiki/Pliocene

Chapter 2




• Summary

Web Alert:Summary of Key Points: Modern Day Climate Change

1.20 of the warmest years on record have occurred in the past 25 years. The warmest year globally was 2005 with the years

2009, 2007, 2006, 2003, 2002, and 1998 all tied for 2nd within statistical certainty. The warmest decade has been the 2000s, and

each of the past three decades has been warmer than the decade before and each set records at their end. The odds of this

being a natural occurrence are estimated to be one in a billion!

2.Temperature data from 1850 to present shows that there has been an increasing trend and the rate of warming has increased

rapidly in the past few decades.

3.Surface temperatures north of latitude 60o are warming at an accelerated rate in the past few decades.

4.The Arctic was experiencing long-term cooling in the past 2000 years according to Milankovitch cycles until very recently. The

cooling trend was reversed during the 20th century, with four of the five warmest decades of the 2000-year-long reconstruction

occurring between 1950 and 2000.

5.Sea ice extent has been dramatically reduced since the 1950s.

6.Since measurements began in 1953, there has been a dramatic decrease in sea ice thickness.

7.Greenland is losing ice mass and the rate is accelerating.

8.Antarctica is losing ice mass and the rate is accelerating.

9.The average mass balance of the glaciers with available long-term observation series around the world continues to decrease.

10.90% of worldwide glaciers are retreating.

11.Much of the heat that is delivered by the sun is stored in the Earth's oceans while only a fraction of this heat is stored in the

atmosphere. Therefore, a change in the heat stored in the ocean is a better indicator of climate change than changes in

atmospheric heat.

12.The heat content of the oceans is increasing.

13.The oceans are taking in almost all of the excess heat since the 1970s which underscores the point that ocean heat content is

a better indicator of global warming than atmospheric temperatures.

14.Much of this ocean heat will be vented to the atmosphere in the future thus accelerating global warming.

15.The Palmer Drought Severity Index (PDSI) curve reveals widespread increasing African drought, especially in the Sahel.

16.Global warming due to human activities is increasing the severity of drought in areas that already have drought and causing

more rainfall in areas that are already wet.

17.According to the US Climate Extremes Index (CEI), extremes in climate are on the increase since 1970.

18.The concentration of CO2 has reached a record high relative to more than the past 500,000 years and has done so at an

exceptionally fast rate.

19.Most of the warming in the past 50 years is attributable to human activities.

20.Although large climate changes have occurred in the past, there is no evidence that they took place at a faster rate than the

present warming.

21.If projections of a 5 oC warming in this century are realized, Earth will have experienced the same amount of global warming

as it did at the end of the last ice age.

22.There is no evidence that this rate is matched to a comparable global temperature increase over the last 50 million years!

23.Sea level gradually rose in the 20th century and is currently rising at an increased rate, after a period of little change between

AD 0 and AD 1900. The trend is 50% greater than that reported by the IPCC in 2007.

24.Sea level is predicted to rise at an even greater rate in this century, with 20th century estimates of 1.7 mm per year.

25.When climate warms, ice on land melts and flows back into the oceans raising sea levels.

26.When the oceans warm, the water expands (thermal expansion) which raises sea levels.

27.IPCC 1990 projected sea level increases were too conservative. The latest observations show that sea levels have risen

faster than previous projections.

28.Greenhouse warming will cause the globally averaged intensity of tropical cyclones to shift towards stronger storms, with

intensity increases of 2–11% by 2100.

29.Substantial increases in the frequency of the most intense cyclones are expected with increases of the order of 20% in the

precipitation rate within 100 km of the storm centre.

30.Rising sea-levels will result in more damage from hurricanes even if hurricane strength remains unchanged.

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http://www2.sunysuffolk.edu/mandias/global_warming/summary_key_points.html

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Chapter 2 2.pdf · Chapter 2 •Changes in Sea ... Skeptical Science(2010) 14. Chapter 2