1 - Foundations Flashcards
How does global warming increase sea levels and what has been observed to date?
5 main contributors
- Thermal expansion of ocean water
- Changes in groundwater storage (land-based water pumped out for use and ends up in oceans)
- Glacier ice loss
- Greenland ice loss
- Antarctic ice loss
Define arctic amplification
The Arctic is warming much faster than the rest of the globe (polar amplification / arctic amplification).
- This accelerates the loss of land-based ice in the Northern Hemisphere, including the Greenland ice sheet, which accelerates sea-level rise and worsens storm surges.
- Global warming melts highly reflective white ice and snow, which is replaced by the dark blue sea or dark land, both of which absorb far more sunlight and hence far more solar energy.
- In the Arctic, compared with lower latitudes, “more of the extra trapped energy goes into warming rather than evaporation.”
- In the Arctic, “the atmospheric layer that has to warm in order to warm the surface is shallower.”
- When the sea ice retreats, the “solar heat absorbed by the oceans in summer is more easily transferred to the atmosphere in winter.”
- In addition, temperatures above thick Arctic ice can get incredibly low, but it cannot get much colder than freezing above open water.
What are the main consequences of arctic amplification?
- The faster the Arctic heats up, the faster the Greenland ice sheet melts, and the faster sea-level rise impacts coastal communities.
- The faster the Arctic heats up, the faster the permafrost melts, and the faster it begins releasing vast amounts of heat trapping carbon dioxide and methane into the atmosphere, further accelerating global warming.
- Studies also suggest it weakens the Northern Hemisphere’s jet stream, which in turn causes certain weather patterns, including droughts, deluges, and heat waves, to get “stuck,” which in turn worsens and prolongs their impact.
According to the studies of NOAA, Francis, and the Potsdam Institute, how does Arctic amplification affect the jet stream?
“Enhanced warming of the Arctic affects the jet stream by slowing its west-to-east winds and by promoting larger north-south meanders in the flow,” NOAA (National Oceanic and Atmospheric Administration) explains.
Context:
The path of the jet stream “typically has a meandering shape, and these meanders themselves propagate east, at lower speeds than that of the actual wind within the flow. Each large meander, or wave, within the jet stream is known as a Rossby wave.” An August 2014 study from a team of scientists from the Potsdam Institute for Climate Impact Research provided a specific mechanism for why we are seeing this jump in extreme weather: Some Rossby waves are stalling out for extended periods of time. The study found that “in periods with extreme weather, some of these waves become virtually stalled and greatly amplified.”
Define albedo
The proportion of the incident light or radiation that is reflected by a surface
What are the current CO2 levels in the atmosphere and what is the maximum concentration that we plan to allow for?
Current levels: Recently past 400 ppm (parts per million)
Current trajectory: Above 600 ppm within this century
Mitigation path: Below 450 ppm (which equates to below 2 C global warming)
Why do winters still seem severe?
I) Warmer-than-normal winters favour snowstorms (especially cold winters often prohibit precipitation)
II) More water vapour in the atmosphere due to global warming, making extreme snowstorms more likely
What are the main incentives to accelerate development and deployment of CCS (carbon capture and storage) technology?
- A rising price on CO2 emissions, making CCS profitable
- Sufficient (=large) subsidies by government entity
- Sufficient (=large) investment and financing by the private sector
… or any combination of these factors
What CCS (carbon capture and storage) technology is currently most cost-efficient?
Integrated gasification combined cycle (IGCC) plus permanent storage in underground sites
Distinguish between the key phases of International Climate Change policy
Before 1990: Framing the Problem
I) political recognition of climate change as a problem
II) Mobilisation of the international community and subsequent formation of country coalitions
III) Articulation of fundamental ideas for the definition of responsibilities
1991-1996: Leadership articulated Defining I) Action to reduce emissions II) Help for developing countries III) Allow for economic growth in developing countries UNCED (1992) 2nd IPCC assessment
1996-2001: Conditional Leadership
I) Significant scientific work
II) Kyoto Protocol (1997), coming into force in 2005
III) US withdrawal from the Kyoto Protocol in 2001
2002-2007: Leadership competition
I) 4th IPCC assessment finds unprecendented growth rates of GHG emissions
II) Focus on market instruments over regulatory instruments
2008+: Leadership during the Financial Crises
I) IPCC mispredictions, and IPCC correspondence showing unethical behaviour become public
II) Economic contraction, and GHG emisisons growth in developing countries
III) 2 C Target defined, BRIC volunteer reduction targets
Describe the distinguishing factors of the 2015 Paris Agreement compared to previous agreements
1: More realistic path towards globally coordinated remissions reductions
2: Connect “voluntary” domestic climate policies to an international review mechanism, making them part of international policy deliberation and coordination (“soft reciprocity”)
3: 5-yearly Transparency regime to make national policies internationally comparable
What are the main emission types and their effect on radiative forcing?
Well-mixed GHG:
CO2 > CH2 > Halocarbons > N2O > 0
Short-lived gases / aerosols:
CO > non-methane volatile organic compounds (NMVOC) > 0 > NOx
Aerosols and precursors:
0 > mineral dust, sulphate, nitrate, organic/black carbon, cloud adjustments due to aerosols, albedo change due to land use
What connects greenhouse gases to warming?
Less heat escaping to space (at wavelengths where CO2 absorbs heat), more heat going back to Earth’s surface – i.e., downward infrared radiation at CO2 wavelengths. No alternative theory so far
Describe the impacts of human activity and fossil fuel development on climate patterns and variables
Global warming refers to observed warming of the planet due to human-caused GHGs. “Climate change” refers to all the long-term changes in climate – sea-level rise, extreme weather (rain, drought, etc.), ocean acidification. (Naturally occurring reasons for climate variability short term include earth orbital and solar output variability, volcanic eruptions, and El Nino/LA Nina events.)
Explain the cyclical, meteorological, and temporal relationships between weather and climate
Climate is statistical average of weather conditions over long periods of time and seasons; weather is atmospheric conditions at a given time/place. “A tropical climate” vs. “a rainy day.” Climate change impacts weather, i.e., the occurrence and severity of weather events.
Cyclical: Natural variability is exacerbated by long-term global warming, producing damaging local/regional effects. Hotter summers, wetter winters for example.
ENSO: El Nino plus climate change = even more extreme heat, storms, such as in 2010 – “an unprecedented run of extreme events.”
Meteorological: Climate change shifts precipitation patterns, making dry areas drier and wet areas wetter in some cases. Weather: more hot days or more rainy/snowy days.
Temporal: Weather is measured over hours/days (specific in time); climate over decades or longer (averages over time). Climate allows comparative averages, i.e., Florida hotter than Greenland.
