Global Environmental Change Lecture Notes
The Earth System Dr. David Hastings, Eckerd College
Sept 2, 2018
Graph of CO2, temperature measured from Vostok, Antarctica ice core Petit J.R., et al. (1999). Climate and Atmospheric History of the Past 420,000 years from the Vostok Ice Core, Antarctica, Nature, 399: 429-436.
★ 405 ppm
rate of increase (ppm CO2/yr) 3.5
rate of increase (ppm CO2/yr)
3.0
2.5
2.0
1.5
1.0
0.5
0.0 1960
1970
1980
1990
2000
2010
2014
Change in temperature from average (C)
2016 st All 17What yrs of 21 century rank among 18 do you see? warmest years on record.
No equivalent to these past 20 years in the temperature record. 2017 broke record for the hottest year on record without an El Niño.
GISTEMP Team, 2017: GISS Surface Temperature Analysis (GISTEMP). NASA Goddard Institute for Space Studies. Dataset accessed 2018-01-03 at https://data.giss.nasa.gov/gistemp Following the common practice of the IPCC, the zero on this figure is the mean temperature from 1961-1990.
1.5
1.0
0.5 0
-0.5 (F)
Global Temperature (C): 1998-2013 Temperature change from average
1.2 1
What do you see?
0.8 0.6 0.4 0.2 0 -0.2 -0.4
1995
2000
2005
2010
2015
The Earth is getting warmer
Change in temperature from average (C)
2016
GISTEMP Team, 2017: GISS Surface Temperature Analysis (GISTEMP). NASA Goddard Institute for Space Studies. Dataset accessed 2018-01-03 at https://data.giss.nasa.gov/gistemp Following the common practice of the IPCC, the zero on this figure is the mean temperature from 1961-1990.
1.5
1.0
0.5 0
-0.5 (F)
Where is global warming going?
Polar ice is melting
~½ of sea ice extent lost since 1980. Thickness of ice is half Sea ice volume = 1/5 of 1980 volume! Observations suggest climate system is more sensitive than models predict
Polar ice: models vs. observations
positive feedback loop! (aka vicious cycle)
Eckerd College w Sea Level Rise = 3 feet
Where is global warming going?
As the ocean acidifies, organisms such as corals, snails, and calcifying plankton will not be able to make their shells and grow.
www.divegallery.com
www.greendiary.com
www.noaanews.noaa.gov
Zooplankton (Pteropod)
Coral
http://elrid.cult.bg
Phytoplankton (Coccolithophore ) 18
www.travel-vancouver-island.com
www.nceas.ucsb.edu
www.bigmoviezone.com
www.noaanews.noaa.gov
Less certainty about biological impacts Broad agreement that that ocean acidification is occurring and will have large effects on many marine organisms, some positive, some negative.
http://elrid.cult.bg
19
Hurricanes and Tropical Storms The intensity of hurricanes in the North Atlantic has increased over the past 30 years, which correlates with increases in tropical sea surface temperatures.
Tornadoes + hurricanes
PROJECTIONS
Past 1,000 yrs
Past 130 yrs
Miami $2.5 billion Tampa $850 million
Global Climate Change: 101 • It’s happening now – The climate is changing: temperature is rising, oceans are more acidic
• We are causing it – changes are largely due to human influence not “natural”
• Scientists agree: – 97% climate scientists agree that climate is changing; due to human activity – broad consensus in scientific community
• We can’t wait: – If we don’t act now, there will be very serious consequences.
• We can fix it: – We can do something to reduce CO2 emissions. Solar and wind power are cheap, profitable, and are good business. JOBS US has abundant clean energy: offshore, onshore wind; solar in SE and SW