L19

Question 1

for there to be risk what other to things are needed

Answer 1

vulnerability and sensitivity

Question 2

why is climate change putting ecosystem at such risk?

Answer 2

because climate change is fast and ecosystems cant respond fast enough

Question 3

when is the resilience of ecosystems likely to be exceeded by?

Answer 3

this centrury

Question 4

what are some disturbances that will test the resilience of ecosystems

Answer 4

flooding 
drought 
wildfires 
insects 
ocean acidification

Question 5

approximately what percent of plants are at risk of extinction if global temps increase by 1.5-2.5

Answer 5

20-30%

Question 6

what is one negative impact ocean acidification will have on marine organisms

Answer 6

they may struggle to make shells

Question 7

In regards to re-distribution rates have most animals had to move to cooler or warmer environments

Answer 7

cooler due to rising temp

-phytoplankton moved the most

Question 8

what would happen if we got to RCP 8.5, could animals migrate fast enough

Answer 8

animals like moose, cheetah and butterfly could potentially survive however some species like trees and monkeys etc would not be able to move fast enough

Question 9

how has the spread of boreal forests changed

Answer 9

shift poleward

Question 10

explain mountain ecosystems, and what happens if the whole mountain was warmed

Answer 10

the temperature as you rise up the mountain cools so lots of different ecosystems in bands. If the temperature of the whole mountain rises, the bands of species move upward which leads to more competition and some species loss at the top that get pushed out.

Question 11

summer heatwave 2003 was the hottest summer since…

Answer 11

1500AD

Question 12

in the summer of 2003 what where the ozone exceedances

Answer 12

90ppbv

Question 13

how many standard distributions away from the mean was the summer heatwave of 2003

Answer 13

5 sd

Question 14

what was the chances that the summer heatwave of 2003 was going to happen

Answer 14

4 billion

Question 15

what was the number of excess deaths in England and wales and from which dates

Answer 15

2045 deaths from 4-13 august 2003

Question 16

what percentage deaths were attributable to air pollution in heatwave of 2003

Answer 16

33%

Question 17

as well as the increase in average rainfall what other factor can have a big impact on crop yield

Answer 17

the spread of the rainfall events, whether they are spread or packed into short time periods

Question 18

what is a FACE experiment

Answer 18

Free Air CO2 Enrichment

Question 19

what are the effects of climate change on crop yields (5)

Answer 19

• crop growth and yield will be enhanced by elevated CO2
• Warmer seasons will be shorter and yields less … but, adaptation can counter this to some extent
• A few days of hot temperature can severely reduce yields
• Crops will be vulnerable to variability in rainfall
• These processes will interact, and the details matter

Question 20

on average what are the predictions of climate change effects on crop yields

Answer 20

Up until 2030s ~1/2 studies suggest crop yields will increase(and half suggest they will decrease)
By end of 21st Century crop yields will decrease

Question 21

when do abrupt climate changes occur

Answer 21

Abrupt climate change occurs when the climate system is forced to cross some threshold, triggering a transition to a new state at a rate determined
by the climate system itself and faster than the cause – Alley et al., [2002]

Question 22

1. When is the Arctic expected to become sea ice free?

Answer 22

1. According to IPCC AR5, the Arctic is likely to become nearly ice free during the summer (September, when sea ice is at a minimum) before 2050 – note that this is not year-round ice-free conditions. However, these projections depend on the emission scenarios used by the models, and this is true for high-end emissions scenarios, such as RCP8.5. See IPCC AR5 Working Group I chapter 11 section 3.4.1 for more info on this: http://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter11_FINAL.pdf

Question 23

2. Sea-level rise depends on several factors other than temperature. List three of these factors.

Answer 23

2. Sea-level rise depends on several factors other than temperature. Three such factors are continental rebound after glaciation (isostatic adjustment), melting of glaciers and ice caps, and changes in the storage of water on land (reservoirs etc).

Question 24

3. Why is air pollution over Europe and the US likely to become more of a problem in a future climate? There are two main reasons, one meteorological and one chemical.

Answer 24

3. Air pollution over Europe and the US is likely to become more of a problem in a future climate because i) biogenic emissions of organic gases can contribute to the production of ozone, which is a major pollutant; ii) there may be an increase in the frequency of anticyclonic high pressure systems in summer, which allows the air to stagnate.

Question 25

4. The 2003 European heatwave was an exceptional event. When in the future is such an event projected to become ‘normal’?

Answer 25

4. The 2003 European heatwave was an exceptional event, but model projections of future temperature suggest such an event could become ‘normal’ by around 2050.

Question 26

5. What is a tipping point?

Answer 26

5. Tipping points are nicely described in the Wikipedia entry (http://en.wikipedia.org/wiki/Tipping_point_%28climatology%29). It is not a well defined concept. A tipping point defines a time at which a major and rapid shift in the state of the climate system occurs, which may be reversible or irreversible. Because of the lag between the forcing of the climate system and its response, a tipping point could be passed without much obvious change, but the response of the system then becomes inevitable. One example is the melting of the Greenland ice cap. It melts very slowly. But it also takes a very long time (hundreds of years) to reduce the CO2 concentration in the atmosphere to a level that would prevent the melting.

Question 27

6. Towards the end of this century the net carbon exchange with the terrestrial biosphere may become less negative (i.e. the biosphere will still absorb carbon, but it will absorb less than it does today). Why?

Answer 27

6. Towards the end of this century the net carbon exchange with the terrestrial biosphere may reduce partly due to loss of soil nutrients. At present, much of the biosphere is growing at a faster rate due to the extra CO2 in the atmosphere, but this is not predicted to continue indefinitely, and the reservoir of available nutrients for plant growth may start to get exhausted. Another reason why the terrestrial biosphere is predicted to absorb less carbon is because of the direct effects of climate change associated with rising atmospheric CO2, although models have low agreement on the magnitude of this effect.

Question 28

7. Changes in the amount of precipitation can have a significant impact on future crop yields. What other issue related to precipitation has been shown to be important?

Answer 28

7. Changes in the timing of precipitation during the growing season are also important, as shown by the observations and modelling results presented by Prof Challinor’s group.

Question 29

8. What have free air CO2 enrichment experiments told us about the response of crops to increased CO2?

Answer 29

8. Free air CO2 enrichment experiments (FACE) show that crops respond to increased CO2 availability. Some crops grow faster and reduce their loss of water (transpiration) because the stomata close up.

Question 30

9. An analysis of downscaled climate model projections for the UK predicts changes in UK summertime temperatures by 2050. What is the 10th to 90th percentile change predicted to be: 0.1 to 1 oC, 0.5 to 2 oC, 1 to 5 oC, or 2-10 oC?

Answer 30

9. An analysis of downscaled climate model projections for the UK predicts changes in UK summertime temperatures by 2050 of 1 to 5 °C.

Question 31

10. These same model projections suggest a risk of reduced summertime rainfall in the southern part of the UK. There is a 10% chance that rainfall could fall by: 5-10%, 10-20%, 20-30%, or 30-60%?

Answer 31

10. These same model projections suggest a risk of reduced summertime rainfall in the southern part of the UK, with a 10% chance that rainfall could fall by 30-60%. In contrast, winters are predicted to get wetter, so the annual mean precipitation may not change much.