Midterm Study Guide ENVS Climate Change
Natural climate change and Milankovitch Cycles & Sun Spots
Every 100,000 years change in radiation has to do with cycles (25%) and sunspots (1.4%) we have avoided next glacial period.
Precession wobble
Every 21,000 years
Anthropogenic Climate change
Forcing and sensitivity
UV radiation
hits skin and is transformed to infrared radiation
Sun
hot (5,778-15,000,000°K) visible, UV, x-ray, gamma ray radiation is all sun shorter electromagnetic waves.
Monetary Impacts
hurricanes cause loss and damage, decrease in labor and photosynthesis productivity, negative impacts on coastal economies
Kyoto/Paris Protocol
if GHGs mix evenly, well then it doesn't matter where we reduce them. (offsets) So why don't we reduce emissions where it is cheapest to do so (Haiti, South Africa)
Sensitivity
immediate effect of co2 that is transient (short term). Since 1870 (industrialization) 1 degree (350 ppm) 2 degree (450 ppm) and paris agreement is 1.5 degree. 100ppm approx 1 degree of warming.
Why we resist CC knowledge
it is easier emotionally and more convenient politically to reject climate science. Denial is due to a surplus of culture rather than a deficit of information. Climate deniers adopt sceptic claims to climate gate which allowed deniers to claim that climate science emerged from privileged persons rather than disinterested nature. In the United States and Australia democracy has defeated science.
Public fraud
know climate change is true but choose to misinform public. Greenpeace expose exon has funneled money towards groups for doubt and uncertainty in the US. exonsecrets.org (40 years). There are two sides one that is funded to question science and one that is to tell people it is not happening. Stock holders need full discloser.
Global surface termperature change by end of 21st century
likely exceed 1.5 degrees celcius in terms of lowest scenario. Precipitation will increase in high latitudes and lower in pacific and mid latitude, sub tropical areas. 1983-2012 warmest 30-year period of last 1400 years in northern hemisphere. oceans warming, precipitation increasing, arctic sea ice extent decreased.
Common constraints on implementation
limited financial and human resources, limited coordination of governance, uncertainties about projected impacts, different perceptions of risks, competing values, absence of key adaptation leaders and advocates, limited tools to monitor adaptation effectiveness, insufficient research, monitoring, and observation.
Habitable Zone
liquid h2o and the zone moves out if sun brightens or green house gases increase and moves in if planet reflects more sunlight.
Extreme Events
since bout 1950 a decrease in cold temperature extremes and an increase in warm temperature. High sea levels and heavy precipitation events in a number of regions.
Pop displacement
slow onset effects of climate change. drought, desertification, coastal erosion, Sea level rise, internal and cross- border displacement. slow onset events act as threat multiplier. CC may be primary or secondary drive of displacement. Somalia- 700,000 IDPs, drought primary reasons for displacement
Key drivers of future climate
socio-economic development and climate policy to determine global mean surface warming by late 21st century.
Mitigation pathways
the action of reducing the severity of climate change by limit warming to below 2 degrees. When substantial emission reductions are required substantial technological, economic, social and institutional challenges are faced. International cooperation is critical for effective mitigation even though mitigation can also have local co-benefits.
What is the consensus?
the balance of evidence says that, GHGs are increasing in the atmosphere, The atmosphere is warming, There is a discernable human influence, Impacts are serious, amplifying and irreversible, Immediate action is needed
Denial
the climate has always changed, humans are not doing anything
Global sea level
risen by 7-8 inches since 1900
Wishful Thinking
"technology will safe us" someone else will solve climate change example Winston Churchill warning of Nazi Germany, but British simply had wishful thinking that there would not be another war
Direct measurement
satellites, thermometer records
Greenhouse gases
CO2, CH4, N2O, O3, water vapor
3 ways to look at climate change science
science, policy and advocacy, and impacts of climate change
Five reasons for concern
1) unique and threatened systems 2)extreme weather events 3) distribution of impacts 4) global collection of impacts 5) large-scale singular events
Scientific consensus on CC
1. GHGs are increasing in the atmosphere 2. the atmosphere is warming 3. there is a discernable human influence 4. impacts are serious, amplifying, and possibly irreversible 5. immediate action is needed
3 main gases in atmosphere
1. Nitrogen, 78% N2 2. Oxygen, 20% O2 3. Argon .9% AR (CO2 is only .04% of atmosphere)
Energy Balance
1st law of thermo- energy cannot be created or destroyed, only transferred. energy hitting planet earth, must equal energy leaving. hotter an object, shorter the wave length
warmest year on record
2016 with over 2.1 degrees. sixteen of warmest years have been in last 17 years
Health
30% of worlds population living in heat risk areas
Forcing
405 ppm is greenhouse gas concentration and rate of increase of ppm increasing with time. Antartica has less fluctuation than northern hemisphere because less land mass, less forests. Arctic warms 3 times faster light surface.
permafrost melt
50% of below ground carbon, if 10% emitted=80ppm increase=10degrees C change. dead organic matter in permafrost, thaws out, forms methane at bottom of lake, methane bubbles released in summer, and trapped in ice in winter. (Video) flaring methane to turn it to CO2, because CO2 has less GWP
Scientific consensus Democrats vs. Republicans
73% of all voters think global warming is happening, 59% think it is caused by human activities. Most americans favor more climate change research. only 1/3 voters support drilling in Anwar- oil drilling supported over biodiversity?
Carbon concentrations
76% human anthropogenic gases are co2, 16% methane, 6.2%fertilizer/agriculture.
What percentage of scientists believe CC is happening?
97 percent
Greenhouse effect
Aerosols- type of pollution that cools the earth. The UV radiation bounces off cumulonimbus storm clouds. UV radiation comes down to Earth and some is reflected off snow and ice back into atmosphere in "atmospheric window". Some of the UV hits earth and is converted to infrared to infrared radiation. The radiation goes up and heats up cloud and then re-radiated back to earth to keep earth warm. Humans increasing GHG means that there is more re-radiated heat.
Risks and impacts
Agriculture- fragile livelihoods, poorest, most vulnerable people, Ethiopia- children born in areas affected by disasters are 35.5% more likely to be malnourished and 41% more likely to be prevented from growing or developing properly
Sun spots
Amount of radiation coming off the sun is not always constant. Solar cycle is 11 years. In any given year there could be up to 250 sun spots. Edges of sun spots are hottest portion of sun. Peak to peak change
Cryosphere
Arctic sea ice extent well bellow average throughout 2017, Ten smallest minimum arctic sea ice extents have all occurred since 2007, Greenland ice sheet losing ice mass nearly every year over the past two decades
General Circulation Models (GCM)
Atmosphere , hydrologic cycle, land surfaces, oceans. All under constant change and very complex.
Extreme Events
Best documented impacts of weather and climate are associated with extreme events. wildfires.
Impacts of climate change
Changes in climate have caused impacts on natural and human systems on all continents and across the oceans. Impacts are due to observed climate change, irrespective of its causes, indicating the sensitivity of systems to changing climate.
Republican view on CC
Conservative republics consistently disregard climate. As long as the climate change research has to do with energy policy that could generate revenue, the republicans are on board. In collaboration with fossil fuel interests and conservative think tank associate acceptance of global warming science with "liberal" views.
Future climate changes, risks and impacts
Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system. Severe pervasive and irreversible impacts for people and ecosystems. To limit climate change would require substantial and sustained reductions in greenhouse gas emissions and adaptation to limit climate change risks.
3 coping strategies
Denial, blame shifting, wishful thinking
Surface UV
Direct is 77% and reflected is 23%
Change in ocean currents: great ocean conveyer belt
Driven by difference in salinity. Salty warm water dives down near Greenland. If Greenland melts, large influx of fresh water could stop the diving down motion. Would result in much cooler European water.
CC misinformation
Funding, Exxon/Mobil Update 2017, Global Climate, Coalition, Competitive Enterprise Institute, American Petroleum Institute, Western Coal, Association, Koch Industries
Even though we are going into a trough (not a lot of sun spots) why are we seeing warming trend on earth?
GHGs
Oceans
Global sea surface temperatures well above average, Oceans absorb 30% of annual emissions of CO2.
what happens when solar radiation hits the Earth?
Greenhouse effect
Causes of climate change
Greenhouse gas emissions largely driven by economic and population growth have driven concentrations in atmosphere of carbon dioxide, methane, and nitrous oxide that are unprecedented in last 800,000 years.
Our relationship with the sun: the solar budget
H2o boils then when it is in the habitable zone it becomes liquid and outside of this zone it is frozen.
Naomi Oreskes
Harvard science studies professor agrees that humans are causing climate change according to Interngovernmental Panel on Climate change which meets every 5-7 years.
Observed changes and their causes
Human influence on the climate system is clear, and recent anthropogenic emissions of greenhouse gases are the highest in history. Recent climate changes have had widespread impacts on human and natural systems. Since 1950s the atmosphere and ocean have warmed and sea level has risen.
Projected changes in the climate system
It is very likely that heat waves will occur more often and last longer and that extreme precipitation events will become more intense and frequent. The ocean will continue to warm and acidify and global mean sea level will rise.
Why are Americans confused?
Koch industries- refining things from oil. Lobbying and writing law ALEC is 40% republicans. Heartland Institute is legislation for republican party which is all anti-environmental law. There is climate change misinformation funding companies such as Exxon/mobil.
Democratic view on CC
Of 28 issues asked about, global warming was ranked 15th most important voting issue but it was 4th most important for liberal democrats and 9th most for democrats. 91 percent of democrats oppose Trumps decision to pull out of paris climate agreement.
Ozone
Polar vortex became unstable and elliptical temperatures rising 5-7 degrees C above long-term mean
Clive Hamilton
Pre-enlightenment governed by the church. Maybe the enlightenment is done, maybe we are done basing opinion on evidence (climate change insinuation)
Five Reasons for Concern
Risks to unique and threatened systems, Extreme weather events, Distribution of impacts, Global aggregate impacts, large-scale discontinuities
Milankovitch Cycles
Studied glacial periods in how they come and go through different cycles. Eccentricity, obliquity, and precession wobble. They can influence the solar radiation intercepted by earth by up to 25%.
Reading 2: Expert credibility on climate change
The warming of the climate system is unequivocal" (2007) "Human influence on climate is clear" (2013) This article looked into the credibility of researchers reporting on climate change, the 1%-2% denying climate change had less credibility anyway
Obliquity
Tilt between 21.6 degrees and 25.5 degrees every 41,000 years
Distribution of impacts
Uneven and disproportionate harm, Poor, elderly coastal areas, Hurricane maria, superstorm sandy, Masai, Kenya: drought affecting farmers, Environmental justice
How long will anthropogenic carbon dioxide and its climate impacts persist?
Upper ocean will absorb and acidify including land biosphere uptake. The deep ocean will uptake and acidify while terrestrial carbon accumulates. Neutralization will occur by sediment dissolution and carbon weathering. It will take 100,000 years to get back to prehistoric levels of 250 ppm
How do they get temp in past?
Use ratios of O16 and O18. When temp is warmer there is more O18, when cooler, more O16
Global aggregate impacts
a. Economic costs of inaction b. Biggest death event happen in poor areas c. Hurricane Katrina costliest insurance
Extreme weather events
a. Heat waves, floods, droughts, wildfires, hurricanes/storms b. Taclaban, phillipines, hit twice by super typhoon, Yet rebuild in same vulnerable area
Risks to unique and threatened systems
a. Species extinction, coral reefs, tropical glaciers, island nations and indigenous people such as Tuvalu b. Walrus- loss of sea ice=loss of habitat
Large-scale discontinuities
a.Substantial loss of ice sheets b.Ocean circulation change c.Forest dieback
Future pathways for sustainable development
adaptation and mitigation are complementary strategies for reducing and managing the risks of climate change. Emission reductions over the next few decades can reduce climate risks, increase prospects for effective adaptation, reduce the costs and challenges of mitigation in the longer term and contribute to climate-resilient pathways for sustainable development
Proxy measurements
alkenones sediment for shells, boron isotopes for ocean PH, leaf stomata for fossilized plants, ice cores.
Foundations of decision-making about climate change
analytical approaches for evaluating expected risks and benefits, recognizing the importance of governance, ethical dimensions, equity, value judgments, economic assessments and diverse perceptions and responses to risk and uncertainty
Three big low probability, high impact
carbon positive feedback: permafrost, methyl hydrates, Ocean acidification, Change in ocean currents: great ocean conveyer belt
Oceans under GCM
circulation, temperature stratification
Future risks and impacts caused by a changing climate
climate change will amplify existing risks and create new risks for natural and human systems. There will be environmental injustice.
Earth
cool (288°K) radio, microwave, and infrared radiation. Earth radiation is longer electromagnetic waves.
Land surfaces
cover types, vegetation, soil moisture, snow cover
eccentricity
elliptical orbit every 100,000 years around sun effects solar radiation
Latent heat
evapotranspiration which can cause ocean storms
Climate change beyond 2100, irreversibility and abrupt changes
even if anthropogenic emissions of greenhouse gases are stopped aspects of climate change and impacts will continue. The risks of abrupt of irreversible changes increase as the magnitude of warming increases.
Response options for mitigation
mitigation measures intersect with other societal goals creating the possibility of co-benefits or adverse side effects. If well managed these intersections can strengthen the basis for undertaking climate action.
Blame shifting
moral disengagement where people disavow their responsibility for problem or solutions. Blaming China because they have more GHGs.
Adaptation and Mitigation
no single option is sufficient by itself. Effective implementation depends on policies and cooperation at all scales and can be enhances through integrated responses that link adaptation and mitigation with other societal objectives.
Greenhouse gas mixing
over 3 years GHGs mix evenly in atmosphere. Highly unequal- majority of sources in northern hemisphere, majority of "sinks" also in northern hemisphere
Paleo and proxy measurements
paleo: looking at past Proxy: other things that indicate temperatures that go back millions of years. Ice cores: see effect of temperature in geological record can count years based on layers created by ice. Use mass spectrometer to find out how much co2 in bubbles by extracting air sample from core
Irradiance of sun
plus or minus 1.5% W/m3
Drivers of anthropogenic GHG emissions
population, economics, lifestyle, energy use, land use patterns, technology, climate policy
Hydrologic cycle
precipitation, evaporation, runoff
Backcasting
predict future temperature by knowing past
Atmosphere
pressure, wind, temp, solar radiation, clouds, moisture
Think Tanks
promotes systematic discrepancy. The Kochtopus is the influence of koch cash that profit from oil, gas, fracking, forest products.
Adaptation
reducing vulnerability and expire to present climate variability including policy design and disaster risk reduction. Adaptation focuses primarily on local to national scale outcomes but its effectiveness can be enhanced through coordination across governance scales including international cooperation.
Aerosols
the same molecule that causes acid rain cools the earth
Solar insolation
the solar radiation intercepted by earth.
Common enabling factors and constraints for adaptation and mitigation responses
they are supported by common enabling factors which include effective institution and governance, innovation and investments in environmentally sound technologies and infrastructure, sustainable livelihoods and behavioral and lifestyle choices.
Where is it warming?
upper ocean and atmosphere.
Natural rang of variability of CO2 in atmosphere?
~180-300 ppm. 405 ppm not seen for at least 2 million years and probably 20 million years and Strong correlation and b/n GHGs and temp.
