Global Climate Change Evidence And Drivers Lec 18 Flashcards
People often confuse what is happening where they live as an indication for what is happening globally, true or false?
True
When was the 2nd warmest august behind 1998?
August 2011
Global warming is now referred to as ?
Climate change
What indicators increase in a warming world
Air temp
Humidity
Ocean heat content
Sea level
Sea surface temp
Temp over oceans and land
In a warming world do the indicators increase or decrease?
Decrease
How do we know with some certainty past climatic trends?
Proxy data
The study of past climates
Paleoclimatology
Physical characteristics of the past Environmental conditions
Proxy data
Proxy data can come from?
Tree rings
Ice cores
Fossil pollen
Ocean sediments
Coral
Historic data (ships, newspapers wtc,)
What are corals skeletons made from
Calcium carbonate
What does calcium carbonate include?
Isotopes of oxygen and trace metals that can determine temp of water the coral grew
Identify plant species from which they came?
Pollen grains with distinct shapes
What do the pollen grains say?
Kinds of plant’s growing at time of deposit and climate of the area
What influences tree growth, patterns in rings, and density
Climate conditions
Trees contain?
Annual records of climate
Earths oceans and lakes have?
Sediment
What do scientists do with sediment?
Drill cores and examine the fossils and chemicals to interpret past climates
A sedimentary rock with a hardened cement of calcium carbonate that binds other materials such as gravel, sand, clay and slit
Caliche (western USA)
In an ice core which layer is more recent?
Top
What do the air bubbles in ice core contain?
Chemicals
World’s premier center for archiving, processing, and researching climate data
NOAA NCDC (National climatic data center)
What are done with the NCDC’s observations
Processed
Quality controlled
Behavior is examined over time
Has our past climate been stable?
No
Why hasn’t past climate been stable?
-Earths orbit is round (closer to sun in summer)
-Earth’s current tilt is different from 9,000 yrs ago (cool summers & warm winters)
-Earth’s position is closer to the North star (in 12000 yrs itnwill point towards Vega)
What 3 things explain past climate variation?
Milankovitch cycles
What are theMilankovitch cycles?
Orbital eccentricity
Axial tilt (angle)
Axial precision ( direction)
What is current axial tilt?
23.4 used to be 24.5
What is driving rapid and large increase in global temp?
Human population; correlation between population growth and increased carbon emissions
How many tons of CO2 added to atmosphere per person/ yr ?
1
Large amount of green house emissions come from
Burning energy
Long term storage of carbon?
Buried fossil fuels
The keeling curve uses what pattern?
The sawtooth (plants take up CO2 during year)
400 parts per mil for the first tome when?
May 9 2013
When was the last time 400 parts per mil happened?
Before modern day humans (3-5 mil years ago)
CO2 falls in summer and rise in the winter, true or false?
True
Carbon comes in what 2 forms?
12 and 13
Which carbon is lighter and more common?
12, 13 has an extra neutron
Which carbon is left behind during photosynthesis? ( plants prefer one over the other)
13
What is the process of plants using Carbon 12 called?
Stable Isotope Fractionation
If increase in atmospheric CO2 is from burning fossil fuels, what is happening?
Relative amount of Carbon 13 to Carbon 12 will be decreasing
Is there more or less carbon on earth?
No , it is just distributed differently. More in atmosphere than the ground
