Further reading reference cards

Question 1

Quote (Wanner et al., 2008).

Answer 1

The Northern Hemisphere (NH) summer position of the Intertropical Convergence Zone (ITCZ) moved gradually southward during Holocene due to redistribution of solar energy via orbital forcing.

Summertime cooling of Northern Hemisphere and changing temperature gradients in oceans during the Holocene increased amplitude of El Nino Southern Oscillation (Wanner et al., 2008)

Question 2

Quote (Rafferty, 2014)

Answer 2

Scientists argue increases in solar radiation, no volcanic activity (limited aerosols) and changes in ocean circulation caused the MWP. Uncertainties in reliability of records, impossible to know for sure (Rafferty, 2014).

Question 3

Quote (Matthews & Briffa, 2005).

Answer 3

Some argue the LIA was caused by decreased solar radiation, others say increased volcanic activity (more aerosols), low summer insolation in Northern Hemisphere - uncertain as to why.

Most agree LIA was amplified by sea ice feedback’s. Albedo effect reflected much of the sun’s energy back into space (Matthews & Briffa, 2005).

Question 4

Quote (Li et al., 2016)

Answer 4

Climate reconstructions using multiple proxies provide the best results as they reduce the number of uncertainties. If multiple proxies agree then interpretations are more likely to be correct.

Tree ring proxy: + most widely distributed and used proxy, high resolution, dating of tree rings is effectively absolute. - Limited ability of capturing slow climate change variability.

Borehole temperatures: + Temperature-depth profiles from boreholes contain records of past surface temperatures due to thermal diffusion. - Only retains long term trends, harder to recover data the further back in time you go (li et al., 2016).

Question 5

What is NASA currently working on?

Answer 5

A mission called GeoCarb, which involves mapping concentrations of key carbon gases from geostationary orbit to improve our understanding of the carbon cycle (NASA, 2018).

Question 6

Name some benefits of NASA’s GeoCarb project:

Answer 6

Will let us see how different weather patterns influence carbon dioxide and methane levels (useful as global warming is changing weather patterns).

Will help us determine how much carbon dioxide is removed from the atmosphere by forests.

Will measure SIF (the faint glow emitted by leaves during photosynthesis) which will allow us to monitor the effects of drought on photosynthesis in various ecosystems.
(NASA, 2018).

Question 7

When is NASA’s GeoCarb expected to launch?

Answer 7

early 2020s (NASA, 2018).

Question 8

Quote (The Guardian, 2018)

Answer 8

In 2017, the record damage cost to the US caused by climatic hazards reached a new record (The Guardian, 2018) - proves impacts of global warming.

Question 9

Discuss desertification in China and include the reference.

Answer 9

Increasing desertification and sandstorms in China has caused hundreds of thousands of people to abandon their homes.

Since the 1950s the amount of desert in China has increased by an area the size of Germany and France combined.

(National Geographic, 2017).

Question 10

How has climate change impacted desertification globally? Include reference.

Answer 10

Desertification, land degradation and droughts have increased globally during the 20th-21st centuries.
Throughout the past 40 years, Earth has lost a third of its arable land to erosion, degradation and droughts.
(National Geographic, 2017).

Question 11

What is the Great Green Wall? Why was it made? Include reference.

Answer 11

The Great Green Wall is an ecological engineering effort to address the desertification problem in China.

Millions of trees were planted along the Gobi desert’s borders, increasing world forest by 10%.
(National Geographic, 2017).

Question 12

Name a problem with China’s Great Green Wall (include reference).

Answer 12

After planting people do not take care of the trees meaning they often die and fail to mitigate desertification.
(National Geographic, 2017).

Question 13

Why is it important to study modern and Holocene climates? Include reference.

Answer 13

Studying them provides essential information for understanding climate dynamics and future climate changes (Zachos et al., 2008).

Question 14

How could carbon stored in soils and low aquatic systems cause positive warming feedbacks?

Answer 14

Global warming makes some places drier which increases the likelihood of fires. If dried out wetlands and soils catch fire the carbon stored within them would be released to cause further warming.
(Zachos et al., 2008).

Question 15

Why is it important to take similar archives from multiple places?

Answer 15

Because having e.g. ice cores from different parts of an ice sheet increases the reliability of climate interpretations.
(Vinther et al., 2006).

Question 16

Name some potential causes of uncertainties for data obtained from ice cores:

Answer 16

Imperfect core stratigraphy/layers, core loss during drilling/handling, incorrect measuring of the core etc. (Vinther et al., 2006).

Question 17

What has been the main driver of ecological changes in central Turkey over the last two millennia?
(Include reference).

Answer 17

Human impacts.

England et al., 2008

Question 18

What four main land use phases has central Turkey undergone over the past two millennia?
(Include reference).

Answer 18

1. Cereals and tree crops.
2. Landscape abandonment and establishment of secondary woodland.
3. Re-establishment of cereal-based agriculture.
4. Agricultural intensification.
   (England et al., 2008).

Question 19

What proxies were used to identify land use changes in central Turkey over the past two Millennia?
(Include reference).

Answer 19

Pollen and Charcoal data.

England et al., 2008

Question 20

What was the Paleocene-Eocene Thermal Maximum (PETM)?

Answer 20

A time period with a rapid temperature increase around 8°C above the average temperature today.
(Gehler et al., 2015).

Question 21

What caused the Paleocene-Eocene Thermal Maximum (PETM)?

Answer 21

Some argue seabed methane emissions was the main cause of the PETM (Gehler et al., 2015), others argue it was volcanic activity which released massive amounts of carbon (Gutjahr et al., 2017).

Question 22

What are Ice Age cycles controlled by?

Answer 22

The earth’s orbit (precession, obliquity and eccentricity).

Hodell, 2016

Question 23

What does PETM stand for?

Answer 23

Paleocene-Eocene Thermal Maximum.

Question 24

Which reference is associated with most mitigation strategies?

Answer 24

(Vonberg, 2017)

Question 25

Name an advantage of putting a giant sunshade in earth (include reference):

Answer 25

It would have an immediate effect (Vonberg, 2017).

Question 26

Name some disadvantages of putting a giant sunshade in space (include reference):

Answer 26

It would be extremely expensive.

It would take decades before this may be possible but even then it is unlikely.

It could significantly impact climates and hydrological systems.

(Vonberg, 2017).

Question 27

Name an advantage of Synthetic trees (include reference):

Answer 27

They are a thousand times more effective at absorbing CO2 than normal trees (Vonberg, 2017).

Question 28

Name some problems with synthetic trees (include reference):

Answer 28

Would require hundreds of thousands of trees to meet warming/mitigation targets (huge amount of space).
Deep burial sites for the captured carbon would need to be found.
(Vonberg, 2017).

Question 29

What is the reference for biochar?

Answer 29

(Woolf et al., 2010).

Question 30

What is biochar? How can it be used as a negative emission solution? (include reference).

Answer 30

A type of charcoal rich in carbon made from biomass.

Burning biomass to produce biochar generates energy and the carbon is locked away within it for hundreds of thousands of years (Woolf et al., 2010).

Question 31

Name some advantages of biochar, include reference.

Answer 31

Biochar can be added to soils to increase productivity.

It is a source of renewable energy.
(Woolf et al., 2010).

Question 32

Name some disadvantages of biochar, include reference.

Answer 32

There are substantial uncertainties regarding its impact and sustainability.

Clearance of forests to provide land for biomass-crop production could cause greenhouse gases in the atmosphere to increase rather than decrease (Woolf et al., 2010).