global warming 2 Flashcards Preview

Past and Future Climate and Environmental change > global warming 2 > Flashcards

Flashcards in global warming 2 Deck (27)
Loading flashcards...
1

what GHG contributes most to CC?

Methane

its stored in hydrate deposits and in permafrost eg high arctic and siberia

2

positive feedback examples

temps warm > permafrost thaws> co2 and ch4 released

GHG increases> earth warms > increase in water vapour

3

negative feedback example

more clouds> more sunlight reflection> less radiation

4

define anomaly

amount of deviation from accepted normal value of that quantity

data - mean = anomaly

5

what year did we hit 1.5 degree warming

2016

6

what tells us cold and warm years

striped graphs

5 warmest years are recent

coldest years are in past

7

how is it hard to predict climate change?

as warming not evenly distributed

warming usually higher in high latitudes

earth climate is non linear dynamical system

8

what was the warming pause in 2000?

here there was no real trend in temp

it wasn;t predicted

don't know why is happened

lots of energy stored in oceans and linked to el nino and la nina

9

name 2 ways we see climate change impact?

glacier recession -169 glaciers all show same trend - problem for water sources and tourism

arctic sea ice reduction - ice cover shrunk by 9% over 1976-2000 and thats increased to 13.5% decrease

10

if east antarctic ice sheet melted how much would sea evel rise?

65m

11

if west antarctic ice sheet melted how much would sea evel rise?

3.4 m

12

if greenland ice sheet melted how much would sea evel rise?

7.5m

13

if arctic sea ice melted how much would sea evel rise?

0m

sea ice doesn't contribute to sea level change - only land ice does

14

name 2 ways sea level rises

ocean exppansion

melting glaciers

15

how much does ocean expansion contribute to sea level rise 2005 data?

2/3 from ocean expansion

16

how much does melting glaciers contribute to sea level rise 2005 data?

1/3

howevr melting glaicers contribute more to sea level rise than in the past

17

why is sea level rise not globally unifrom?

eg isostatic rebound - removal of glacial weight from continent, the crust will rebound after losing the weight, land rises relative to the sea, other side of land subsides eg North of uk lifting and south is subsiding

18

describe the impact of global warming on coral reef?

bleaching.

coral get nutrients from photosynthetic algae.

when water is too warm the coral expel algae living in their tissue.

bleaching can be reversible if water cools down

happens in warm waters and when ocean acidifies

19

give examples of bleached coral reefs

great barrier reef worst bleaching in 2016

japans biggest reef - 75% of it has died from bleaching

20

describe ocean acidification

1 half of co2 released over 200yrs has been absorbed by oceans.

co2 in sea water creates carbonic acid which lowers waters PH making it more acidic

this raises hydrogen ions in water and limits organisms acess to carbonate ions which are needed for shells

21

how do we predict cc?

climate computer models - solve math equaltions and asses land/ocean/cryosphere interactions

however not all accurate
data takes a while to process

22

what are the IPCC scenarios

RCP2/4.5/6/8.5

Possible climate futures - all possible depending on how much GHG emitted

23

what is the prediction of global surface temp?

1.5 - 4 degrees

24

what is radiative forcing?

difference of insolation absorbed by earth and energy radiated back to space

25

what is the prospected seal level rise by end of 2100?

40-83 cm

increased recently by 20-60cm

26

what is the prospected sea ice extent by 2100?

worse case scenario is ice free by 2070

27

"All models are wrong. Some are useful"

attempt to stimulate reality

all have errors - comparable to proxy data

all tested, comapres and evaulated