2.A - Humans have influenced the climate to form a new epoch "the Anthropocene"

Question 1

what scientific evidence is there that evidences human induced global climate change?

Answer 1

• correlation between GGs (CO2 is now at 410ppm) and temp rise. methane on the rise due to cattle and landfill
• there has always been natural fluctuation, but the pattern suggests that we are now outside the realm of this natural fluctuation
• in the last 140 yrs the temp has risen so sharply that it cannot be just responding to changes in the earth’s orbit (too quick)
• avg global temps have ↑ by up to 0.6° since the 19thC; the 4 hottest years since accurate records began have all been in the last decade
• temperature is often measured near urban centres e.g. Las Vegas, which have grown over time and therefore the warming is simply the result of the “urban heat island effect”

Question 2

what scientific evidence is there that goes against human induced global climate change?

Answer 2

• there has always been a natural fluctuation in global temps even before humans had the technological capability to affect it.
• the fluctuation in temps could/or can be an effect of sunspot activity, volcanic activity and orbit cycles
• 95% of the CO2 in the atmosphere is a result of natural sources, such as volcanoes
• water vapour is responsible for 96% of the greenhouse effect
• accurate records simply don’t cover a long enough period to be useful
• between 1930 and 1970 temps actually dropped
• temperature is often measured near urban centres e.g. Las Vegas, which have grown over time and therefore the warming is simply the result of the “urban heat island effect”

Question 3

describe the broad trend of increases in global temperatures between 1880 and 2015

Answer 3

• there has a consistent rise in global land and ocean temperatures in the 20th c
• 9/10 of the warmest years since 1880 have occurred since the start of the new millennium
• while rising temps have been the dominant trend of the past 135 years, several anomalies occurred in the period

Question 4

evidence of climate change - SHRINKING GLACIERS/ICE SHEETS

Answer 4

• in the Alps, valley glaciers may shrink by 80-96% by the end of the century
• more than 110 glaciers have disappeared from Montana’s Glacier National Park over the past 150 years, and the researchers estimate that the park’s remaining 37 glaciers may be gone in another 25 yrs

Question 5

why are glaciers good indicators of climate change?

Answer 5

• they are very sensitive to changes in environment (temperature or precipitation)
• and respond to climate fluctuations by growing or shrinking

Question 6

how are glaciers measured so they can indicate the rate of global climate change?

Answer 6

• high resolution satellite imagery
• which can be compared with historical maps/information
• build up a global database of imagery

Question 7

what are the impacts of a reduction in the size and number of the world’s glaciers?

Answer 7

• more than 110 glaciers disappeared from Glacier National Par in 150yrs
• approc 160,000 glaciers occupy the earth’s polar and mountain regions
• even glaciers w/in the same national park can respond differently to temperature fluctuations

Question 8

how is glacier national park changing?

Answer 8

• 1800s = 153 glaciers
• today = 25 glaciers
• measured by repeat photographs every other year (so much change that they’re now ↑ frequency)
• nowadays satellite/GPS technology can be used to track rate of change
• Glaciers are sensitive to changes in environment. seeing rates of change 2-3x global averages
• affect things downstream = huckleberry crop = food for grizzly bears

Question 9

evidence of global warming - RISING SEA LEVEL

Answer 9

• flandrian transgression = sea level rise by 120m
• sea level began to rise mid 19thC. since 1990 the avergae rise has been 1.0-2.5mm/yr
• recent evidence from satellite altimetry suggests that sea level is currently rising at a faster rate (3mm/yr) and this trend will continue
• 2 processes account for global sea level rise:
  > the thermal expansion of the oceans as the world’s climate warms
  > and the melting of land-based ice sheets and glaciers

Question 10

how has the avg loss from glaciers changed recently?

Answer 10

• the decadal average loss from glaciers in the World Glacier Monitoring Services Reference Network quintupled over the past few decades, from the equiv of 6.7 inches of liquid water in the 1980s to 18inches in the 1990s.
• ice loss from the Greenland ice sheet ↑ 7 fold form 34 bill tons per year betweeen 1992-2001 to 247 bil tons per year between 2012-16.

Question 11

what does the greenhouse effect cause?

Answer 11

• the greenhouse effect causes the atmosphere to trap more heat energy at the earth’s surface and within the atmosphere by absorbing and re-emitting longwave energy
• of the longwave energy emitted back to space, 90% is intercepted and absorbed by GHGs.
• without the greenhouse effect the Earth’s avg global temp would be -18°C rahter than the present 15°C.

Question 12

what have the actions of humans caused in the last few centuries?

Answer 12

• in the last few centuries, the activites of humans have directly or indirectly caused the concentration of the major GHGs to ↑
• scientists predict that this increase may enhance the greenhouse effect making the planet warmer.

Question 13

what is the atmospheric concentration (ppm) of carbon dioxide?

Answer 13

420

Question 14

what is the atmospheric concentration (ppm) of methane?

Answer 14

1.85

Question 15

what is the atmospheric concentration (ppm) of nitrous oxides?

Answer 15

0.315

Question 16

what is the atmospheric concentration (ppm) of ozone?

Answer 16

0.04

Question 17

what is the atmospheric concentration (ppm) of CFCs?

Answer 17

0.0004

Question 18

what is the total potental impact of carbon dioxide?
(ppm x Global warming potential)

Answer 18

420

Question 19

what is the total potental impact of methane?
(ppm x Global warming potential)

Answer 19

46.25

Question 20

what is the total potental impact of nitrogen oxides?
(ppm x Global warming potential)

Answer 20

93.2

Question 21

what is the total potental impact of ozone?
(ppm x Global warming potential)

Answer 21

80

Question 22

what is the total potental impact of CFCs?
(ppm x Global warming potential)

Answer 22

5.64

Question 23

what are the anthropogenic sources of carbon dioxide?

Answer 23

• CO2 is ↑ in the atmosphere due to combustion of fossil fuels, deforestation and marine pollution (which kills photosynthesisng phytoplankton)

Question 24

what are the anthropogenic sources of methane?

Answer 24

• methane is ↑ in concentration due to ↑ livestock farming and rice farming (this can be linked to population)
• in addition there is leakage from gas pipes/fields, coalmines and landfill sites (an anaerobic breakdown of rubbish)

Question 25

what are the anthropogenic sources of nitrogen oxides?

Answer 25

emitted from vehicles and power stations

Question 26

what are the anthropogenic sources of ozone?

Answer 26

• to be more precise this is tropospheric (i.e. found in the lower atmosphere rather than in the ozone layer)
• it is created when sunlight causes a photochemical reaction with hydrocarbons and nitrogen oxides from vehicles

Question 27

what are the anthropogenic sources of CFCs?

Answer 27

• have been used in aerosol propellants, refrigerators and fire extinguishers
• they were banned in 1987 as they were causing extensive damage to the ozone layer (which protects us from harmful UV rays)
• however they have a lifespan of 100+ years so still exist in the lower atmosphere

Question 28

how is LAND USE CHANGE a reason for rising GHG emissions since the pre-industrial era?

Answer 28

• around 1/3 of GHG emissions come from land use changes and the emission of carbon from deforestation, drained wetlands and cultivated soils
• today 40% of the land surface is taken up by agriculture, while up to 25% of the world’s forests have been lost since 1700

Question 29

how is RISING LIVING STANDARDS a reason for rising GHG emissions since the pre-industrial era?

Answer 29

• an ↑ wealthy population has a larger carbon footprint
• currently the US has the largest in the world with avg households producing about 50 tons CO2e per year.
• this is 5 times greater than the global avg

Question 30

how is the HUGE SURGE IN DEMAND FOR ENERGY a reason for rising GHG emissions since the pre-industrial era?

Answer 30

• there has been a huge surge in the demand for energy due to GLOBALISATION, TECHNOLOGICAL ADVANCES and INDUSTRIALISATION
• manufacturing industries, power station and transport burn more fossil fuels
• 87% of the world’s energy production is from burning fossil fuels and this produces CO2
• this contributes about 3/4 of the world’s atmospheric carbon since 1750.
• in an ↑ globalised world more people are flying on long haul flights and more goods are air freighted. planes have a carbon footprint 29x greater than high speed trains.

Question 31

how is RAPID POPULATION GROWTH a reason for rising GHG emissions since the pre-industrial era?

Answer 31

• rapid population growth 1 billion in 1800 to 7.4 bill in 2015
• a greater number of people in the world are obviously contributing more GHGs

Question 32

why is the percentage contribution of emissions between Europe and Asia different between 1960 and 2011?

Answer 32

• most CO2 emissions 1850-1960 originated from industrialised economies of NA and Europe. Historically USA has dominated
• since 1960, however, significant regional shifts have occured in emissions of CO2 and other GHGs.
• Asia’s emissions have ↑ massively while those of NA and Europe have stabilised and declined (Germany and UK)
• China overtook USA
• economic sectors - China = more primary/secondary economy whereas USA/UK have deindustrialised and outsourced production to China.

Question 33

when methane is included alongside carbon dioxide, Brazil and Indonesia rank as the 3rd and 4th biggest emitters. Why is this?

Answer 33

• this is due to the effects of large scale deforestation in Amazonia and Indo-Malaysia.
• scientists predict no amazon rainforest in 40-50 yrs
• its easy for people in UK to say you must stop deforesting when people are already enjoying a good standard of living

Question 34

which sectors dominate the UK economy?

Answer 34

• the service sector dominates the UK economy, contributing around 80% of GDP; the financial services industry is particularly important, and London is the world’s largest financial centre.
• Britain’s aerospace industry is the 2nd largest national aerospace industry
• its pharmaceutical industry, the 10th largest in the world, plays an important role in the economy

Question 35

what has boosted the UK economy?

Answer 35

• the economy is boosted by the North sea oil and gas production
• its reserves were estimated at 2.8 bill barrels in 2016, although it has been a net importer of oil since 2005.

Question 36

what are the regional variations in the UK economy?

Answer 36

• there are significant regional variations in prosperity, with South East England and NE Scotland being the richest areas per capita.
• the size of London’s economy makes it the largest city by GDP in Europe

Question 37

how has the UK economy changed since the 18th c?

Answer 37

• in the 18th C the UK was the first country to industrialise and during the 19th C it had a dominant role in the global economy, accounting for 9.1% of the world’s GDP in 1870
• from the late 19th C the Second Industrial Revolution was also taking place rapidly in the United Staes and the German Empire; this presented an ↑ economic challenge for the UK
• the costs of fighting WW1 and WW2 further weakened the UK’s relative position
• in the 21st c however ot remains a global power and has an influential role in the world’s economy

Question 38

what was China’s economy like in the 20thC?

Answer 38

• in the early 20th C China was very much a rural economy and had low numbers of people living in cities
• between the world wars it was dominated by foreign powers

Question 39

what was china’s economy like until the 1970s?

Answer 39

• despite China’s huge population, until the 1970s the country’s economy was overwhelmingly rural.
• with an economy largely dependent on biofuels (timber, animal waste etc.), total emissions of carbon from burning fossil fuels were modest.

Question 40

what was china’s economy like after 1978?

Answer 40

• after 1978, the situation changed dramatically.
• an abrupt U-turn of policy by China’s leaders moved the country away from a strict command economy and the country embraced the free market
• economic liberalisation stimulated international trade and FDI
• thus China emerged as a major player in the global economy, with economic growth based on export led manufacturing.
• today China controls 12% of the world’s exports, compared with just 1% in 1970

Question 41

how did industrialisation change China’s economy?

Answer 41

• industrialisation was accompanied by spectacutal urbanisation; involving hundreds of millions of people, the migration from rural to urban areas in China in the past 40 yrs was the largest population movement in history
• economic progress has raised avg incomes to unprecedented levels.
• GDP per capita rose from $US299 in 1980 to $US12,763 in 2012
• China’s economic development and industrialisation were made possible by massive energy consumption. Most of this energy came from the country’s huge indigenous reserves of coal. Inevitably this produced large increases in carbon emissions

Question 42

how did China’s carbon emissions change as it industrialised?

Answer 42

• unhampered by international protocols like Kyoto, carbon emissions rose 2 and a half times between 2000-2014.
• today China consumes almost as much coal as the rest of the world together
• in 2006 it overtook the USA as the world’s largest emitter of carbon.
• although emission rates have slowed recently, coal still provides nearly 2/3 of China’s energy
• china’s aim to reduce CO2 emissions by 40% between 2005-20 appears to have little chance of success.

Question 43

evidence of global warming - SURFACE, ATMOSPHERIC, OCEAN TEMPS INCREASE

Answer 43

• consistent rise in the 20th century
• temp increased by 1.1C since 1900
• 9/10 warmest years since 1880 have occurred in 21st C
• several anomalies but powerful evidence
• helps determine effects

Question 44

evidence of global warming - INCREASING ATMOSPHERIC WATER VAPOUR

Answer 44

• directly related to temp and rates of evaporation
• warmer temps = more atmospheric mositure
• for every 1C in temperature rise due to increased CO2 levels, water vapour will DOUBLE that warming rate.
• positive FBL - increased atmospheric water vapour = more warming and vapour
• most fluctuations in levels as air can only hold water for so long. constantly in flux.

Question 45

evidence of global warming - DECREASING SNOW COVER AND SEA ICE

Answer 45

• decline of 2% since 1966 of cover in N hemisphere
• snow albedo reflects 70-80% of incoming infrared radiation = increased absorption = PFL
• in summer, sea ice decreases by 8% = more rapid changes and increased temp
• coasts = ecologically sensitive regions (loss of beaches = decreased economic tourism)

Question 46

what are the effects of human activity?

Answer 46

• due to population growth and technology advances
• human kind dominated influence forcing environmental changes
• means our earth has entered a new epoch called the Anthropocene

Question 47

what is the global energy balance and how can humans influence it?

Answer 47

• humans directly and indirectly cause concentrations of major GHGs to increased = enhanced GHE
• there’s always been natural fluctuations but
• patterns suggest its outside the realm of natural
• last 100yrs rise so sharp that can’t be due to earth’s orbit
• correlation between increased GHGs and temp