IB Geog Unit 2 Climate Change

• The natural greenhouse effect is when incoming shortwave radiation (insolation) from the Sun is reflected back by the Earth’s surface and turned into longwave radiation and absorbed by the atmosphere by natural greenhouse gases such as methane, CO2, water vapour etc. which heats up the Earth to ~15°C, making it suitable for life
• Sunspots follow an 11-year activity cycle , they are dark spots on the Sun which occur when concentrated magnetic fields well up to the surface of the Sun, increasing solar radiation output
• Global dimming refers to when suspended particulate matter in the atmosphere reflects solar energy back into space, causing a net cooling effect. Particulate matter can originate naturally from volcanoes or human pollution.
• Albedo is the proportion of incoming radiation that is reflected back into space by the Earth’s surface expressed as a percentage
• Permafrost is ground which has remained at or below 0 °C for at least 2 consecutive years. 80% of Alaska is covered with permafrost and the Dempster Highway in Northwestern Canada is built upon permafrost.
• Temperatures in Alaska have risen by 4 °C since the 1960s and as much as 10 °C in winter months according to NASA
• Methane is a greenhouse gas, large amounts of it are stored in permafrost in permafrost regions such as polar, tundra and mountain regions. Estimates say that the amount of methane stored in permafrost is 2x the amount of carbon in the atmosphere.

  
  

  Decomposition of dead organic bodies such as dead plants, belching from cows and rice farming could cause the release/ production of methane.

  
  

  Methanogens are a type of archaea which produce methane as a byproduct of anaerobic respiration (methanogenesis)
• The USA is the world’s 2nd largest emitter of GHGS, emitting 1/5th of the world’s GHGS while making up less than 5% of the global population

  Shifts from coal to gas fired plants have caused carbon emissions to decrease by 10%
• China is the world’s largest carbon emitter since 2007 as a result of industrialization

  It makes up 1/4th of all global emissions while making up 1/5th of the global population

  It has pledged to reduce the carbon intensity of the country’s growth by using more renewable energy, they spent USD 10b on wind turbines in 2010, about half of the global spending
• India makes up 1/5th of the world population and makes up 5% of all global CO2 emissions
• Qatar is an oil-rich desert state which has high per capita emissions, oil wealth is used to fund high energy usage, including lavish air conditioning
• Japan and Germany have phased out nuclear energy as a result of fears of risks of nuclear accidents after the 2011 Fukushima Nuclear Accident, causing an increase in total emissions as of recent
• Low-income countries may have a high per capita carbon footprint as they rely on wood-burning stoves for heat and cooking
• ENSO (El-Niño Southern Oscillation) is a variation in the direction of trade wind blowing, known as the Walker Circulation, which causes parts of South America to warm and parts of the Indo-Pacific region to cool and vice versa as a result of the movement of warm waters

  El Niño is when South America is warm, El Niña is the opposite

  Extra explanation: Walker Circulation causes ocean upwelling of colder waters in Chile and Peru when winds blow warmer water westward
• The Thwaites Glacier is a glacier in West Antarctica the about the size of Florida, because it slopes downwards into the ocean, it is more susceptible to increase in water temperature as a result of global warming, this has caused its grounding line to shift back and parts of its ice shelf to collapse, increasing glacier flow into the ocean, this could cause the full collapse of the glacier.

  If the Thwaites Glacier collapses, it could cause a 0.65m sea level rise and maybe collapse a large part of Western Antarctica with it, causing a 3m sea level rise.
• Tropical storms are formed when water at the ocean surface is ~26.5 °C, which creates a low-pressure zone above the water, forming winds, carrying water vapour up, which condenses into clouds, releasing latent heat energy, warming up the air and further decreasing pressure and thus, providing more energy for the cycle to continue as winds get stronger, forming a positive feedback loop. The Coriolis effect causes the collection of clouds to begin spinning
• Eccentricity refers to the shape of the Earth’s orbit, which shifts from elliptical to spherical every 100000 years because of gravitational pull from Jupiter and Saturn, when the Earth’s orbit is spherical, it receives 23% more sunlight at its closest approach to the Sun.

  The more spherical the orbit, the more even the seasons are in length
• Obliquity refers to the axis of rotation as it travels around the Sun. It varies between 22.1 and 24.5 °, the greater the axial tilt, the more extreme contrast between seasons. Milder axial tilt promote cooling as more water can form glaciers because of the lower amount of solar radiation received.
• Precession refers to the wobble of the Earth upon its rotational axis, caused by gravitational pull by the Sun and Moon. Axial precession determines the contrast of seasons between Northern and Southern Hemispheres.

  Apsidial precession refers to the variation in the Earth’s orbit.

  The combined effects of both apsidial and axial precession result in a cycle 23000 years
• Eyjafjallajokull is a volcano in Iceland which erupted in 2010, spewing ash which was blown South and East, disrupting European air transport. The eruption cause the melting of ice caps and flooding of nearby farms.

  The Furtwangler Glacier on Kilimanjaro is Africa’s only remaining ice cap, which is melting at a rapid rate.

  Alpine glaciers are thick masses of ice found in deep valleys or upland hollows. They are important in the Himalayas as they are the source of perennial rivers like Indus, Ganges and Brahmaputra.

  China‘s Urumqi No. 1 Glacier has lost 20% of its volume since 1962
• “Boiling Sea” phenomena in Siberia, caused by thawing of permafrost and release of methane
• Antarctica is losing more ice than it gains every year, at a deficit of 70 gigatonnes
• Locust swarms in East Africa and India occured as a result of a series of tropical storms which brought rainwater, which caused an increase in the amount of vegetation
• Carbon offsetting is the practice of compensating for a consumer’s emissions by funding an equivalent carbon emission saving elsewhere, e.g Cathay Pacific

  However, it may justify the use of fossil fuels and due to lack of monitoring, the carbon savings from offsetting are not sufficient
• Geo-engineering is the deliberate, large-scale manipulation of the planetary environment with the objective of counteracting anthropogenic climate change
• Ocean fertilization refers to the addition of nutrients to the ocean to promote phytoplankton growth, which increases the amount of CO2 sequestered.

  
  

  The Haida Salmon Restoration Corporation (HSRC) dumped 120 tonnes of iron-rich dust into the Pacific Ocean West of Haidi Gwaii over the course of 30 days, which resulted in plankton bloom which was confirmed by satellite images.

  
  

  Ocean fertilisation cannot meaningfully contribute to achieve Paris Agreement goals, as the required financial investment is too great to be realistic. There are also potential risks of large-scale disrupting ecosystems
• Enhancing cloud brightness refers to adding aerosols or seawater droplets to increase cloud albedo
• Injecting sulphur dioxide particles or aerosols into the stratosphere helps to form more reflective clouds. However, because of the rapid breakdown of aerosols, the process must be repeated quite often. Moreover, there are concerns that such aerosols may cause the depletion of the ozone layer.
• CCS (Carbon capture and sequestration) is the practice of capturing carbon dioxide, especially from CO2 emitting factories, and storing it within rocks underground.

  Norway is one of the first countries to engage in large-scale CCS projects, but critics say that it has justified the development and expansion of carbon-emitting industries, especially petrol in the case of Norway.
• The Canada lynx is a carnivore which feeds almost exclusively on the snowshoe hare, which lives in snow-covered areas within the region’s coniferous forests. They cannot live in areas where snow cover lasts less than 4 months a year.