4. Climate Change

Describe long-term evidence (and patterns) of climate change and provide specific examples - For each type of evidence, explain how the past data can help us understand present trends and make future projections - Explain how past data confirms that climate change is the result of anthropogenic factors

*not just a cyclical event of changing patterns* 1. Growth rings (age, temp, precip, sunlight, nutrients) 2. Fossilized mud (plant DNA showing historic climate changes). 3. Ice cores - temp estimates based on 02 trapped in bubbles. - go back 100-100s of years - 02 in different isotope forms - 0-16 = "light", less neutrons, more 0-16 means colder climate - 0-18 = "heavy," more neutrons, more 0-18 means warmer climate

3 main sources of CARBON DIOXIDE emissions:

1. Power stations 2. Industry 3. Transportation

Explain how anthropogenic GHGs have contributed to global warming via an enhanced greenhouse effect, decreased albedo, positive feedback loops (How does a negative feedback loop differ?)

Greenhouse effect = warming of the planet due to heat trapped in the atmosphere. Enhanced effect warms MORE than usual. Decreased albedo bc asphalt, dark roofs. Green and white are reflective, but deforestation and glaciers and ice melting. URBANIZATION DECREASED ALBEDO. Positive feedback loop (see increased CO2 example) Negative feedback loop - Increased heat causes more water vapor to be absorbed by clouds = bigger clouds to reflect UV light.

Define anthropogenic.

Human-induced causes.

Explain the role aerosols can play in warming and where aerosol density is the highest globally.

LIGHT aerosols reflect light / DARK aerosols absorb and re-emit light to earth. Most concentrated in South America (also related to Amazon fires and agriculture), Africa (burning biomass). US not as bad because Clean Air Act of the 70s.

List reliable sources of climate change data and explain why vetting sources is so important.

Look at PRIMARY SOURCES - IPCC - NASA - PNAS (Proceedings of the National Academy of Sciences)

Describe IPCC climate projects over next century and how this differs based on different emissions scenarios. (See slides).

Lower emissions scenario Mid-Level emissions scenario Higher emissions scenario 2011-2030 2046-2065 2080-2099

Define aerosols. Examples of natural and anthropogenic aerosol pollutants.

Tiny particles. Suspension of fine solid particles or liquid droplets in air or another gas. NATURAL Fog Dust Forest fires Sea salt ANTHROPOGENIC Haze and smoke Fossil fuels Biomass burning

Describe strategies humans can use to mitigate climate change globally, nationally, and personally - Indicate which strategies are most effective at reducing GHG emissions

- better legislation - carbon capture storage (Shell) - carbon absorbing trees - daily actions like carpooling, short showers, etc. - electric cars - plant based diet

Explain how rising sea surface temperatures threaten coral reef - Describe the process of coral bleaching; how could impact global biodiversity?

- coral reefs located in more shallow areas in ocean bc light needs to reach them - increasing sea temps causes coral bleaching - photosynthetic organisms vacate the coral pores with increased temps

Identify anthropogenic GHGs and their relative abundance, sources, and contribution to warming.

1. Most Carbon dioxide 75% (transportation and energy) 2. Methane 16% (BUT really potent, 1 methane molecule = 20 CO2 molecules) 3. Nitrous oxide 6% (agriculture) 3 main offenders 1. Transportation 2. Power plants 3. Industry 2 main METHANE offenders 1. Fossil fuels 2. Agriculture

CARBON DIOXIDE emissions by country:

1. US & China - most CO2 emissions annually 2. India 3. Russia MAIN POINT: less developed countries have less CO2 emissions

Describe present-day evidence (and patterns) of climate change and provide specific examples. For each type of evidence, describe future projections if humans take no action to reduce GHGs.

1. atmospheric temp - warmer atmospheric trend over last 100 yrs 2. sea surface temp - general increase in sea surface temp over last 100 yrs 3. glacial melt (ARCTIC, GREENLAND, ANTARCTIC) - leads to rising sea level - glacier mass decrease, net loss - wildlife can't adapt (more grizzly bears moving north = competition) 4. rising sea level - cities likely to be underwater by 2070 - thermal expansion causing - abnormal weather patterns and extremes (rain in weird places, dry in some now, etc etc) - altered polar jet stream (bucket of water analogy) - severe storm increase - intensified el nino events bc increase in temp, warm sea temps

Describe some general patterns in species responses to climate change - Provide specific examples of how biodiversity is being negatively impacted by climate change

1. flowers blooming earlier (good for agriculture, BUT causes mismatch for species for food, disrupted reproductive cycles for organisms who feed/pollinate these things). 2. species migrating to higher altitudes and latitudes (GRIZZLY BEARS, CARIBOU) 3. Increasing pests (bark beetle infestations destroying forests)

Define greenhouse gases (GHGs); list naturally occurring GHG and their relative tropospheric abundance.

Atmospheric heat absorbing molecules. NATURALLY occuring include 1. Water vapor 72% 2. Carbon dioxide 26% (exhaling) 3. Methane 9% (hooved animals eating) 4. Ozone 7%

Main point graph of carbon dioxide, methane, nitrous oxide showing...

CO2 greatly increasing over time from 1970 to 2004.

What does IPCC stand for? Who founded it? Purpose?

Intergovernmental Panel on Climate Change created by UN, works with Meteorological Organization It's purpose is to evaluate scientific studies related to climate change to objective assess data and MAKE PROJECTIONS

Identify the different layers of the atmosphere and what gases (%) and human activities occur in each.

Mesosphere Stratosphere (w/ Ozone layer) Troposphere (where we live) In Troposphere, there's 1. Nitrogen (78%) 2. Oxygen (21%) CO2 is only 0.3% of atmosphere but still causes major shift in climate when increased.

Compare and contrast natural and anthropogenic pollutants and their sources.

NATURAL Forest and grass fires Volcanoes ANTHROPOGENIC Industry Agriculture Mining

Explain why the ozone layer is important, how it was being depleted, and what global action preserved it.

Ozone layer protects from UV radiation from the sun. Ozone hole is a depletion of stratospheric atmosphere. It was being depleted by chlorofluorocarbons (CFCs) from AEROSOLS. The Montreal Protocol (1970s) preserved it by reducing CFCs.

Past data predicts future trends: Ice cores ____________ correlation between temperature and CO2 concentration over time CO2 concentration in ice cores correlates to antarctic temperatures at the same time.

POSITIVE

Primary pollutants v. Secondary pollutants

Primary pollutants = immediately damaging Secondary pollutants = primary pollutant mixes with AIR and has a reaction (ex: sulfuric acid)

Define albedo; describe the relative albedo of different types of surfaces and how this can affect warming.

The ability of a surface to reflect away solar radiation. Ice/snow = reflects Ocean = absorbs BUT more dark surfaces (blacktop, roofs) contribute to global warming by heat trapping even more.

Explain how naturally occurring GHGs produce a greenhouse effect and why this is important for life on Earth.

The earth would be inhabitable without the greenhouse effect bc it would be too cold. Sun heats earth's surface, causing earth's surface to give off heat, which gets trapped in the atmosphere since the stratosphere acts like a cap. Problems occur when this cycle is enhanced though.

Explain how scientists know the Milankovitch cycles are not responsible for climate change.

These are: Orbital Eccentricity - elliptical or round movements around the sun, 100k year cycle. Axial Tilt - angle of earth's tilt on its axis changes, 41k year cycle. Axial Precession - bc earth "wobbles", this changes of earth's orientation to the sun ALL OF THESE CURRENT POSITIONS INDICATE WE SHOULD BE IN A COOLING PATTERN

How have the IPCC reports changed?

They have changed over time in their assessment of whether or not climate change is human caused. 1990 didn't quantify human contribution 1995 evidence suggest discernible human influence 2001 human emitted GHGs are LIKELY responsible for temp increase 2007 human emitted GHGs are VERY LIKELY responsible for temp increase 2013 human emitted GHGs are EXTREMELY LIKELY responsible for temp increase

Explain the importance of the 2 degree C threshold and why the IPCC released a new report.

They previously released a report saying the earth cannot go past a 2 degree C threshold, which will cause more years of hot weather, droughts, etc. Mass extinctions. Now 1.5 degree C threshold because we've already warmed 1/2 a degree. We have less time now.

Describe how water vapor can cause a positive feedback loop in an increasing CO2 environment. (Positive does not equal good).

With increased CO2 (or methane for ex), this causing global warming. Warming temperatures causes increase evaporation, which puts increased water vapor in the air, which again warms the atmosphere. Cycle continues.

Define climate change.

alternation in the long-term patterns and statistical averages of meteorological events

Models show that _______________ factors have contributed to rising temperatures. Separating Human and Natural Influences on Climate-Graph - black line = actual temp - blue = natural AND human factors - green = natural factors ONLY black line does NOT follow natural factors only **shows that models do a great job of predicting real temps AND shows anthropogenic factors**

anthropogenic

What is the biggest contributor to present-day climate change?

global warming (consistent rise in earth's temperatures)

**history shows us that as C02 levels rise, so does ____________________** The spike in C02 is always FOLLOWED by a spike in temperature. LAST 150 YEARS SINCE INDUSTRIAL REVOLUTION SHOWS C02 SKYROCKETING

temperature

Positive v. Negative forces Positive forces = ______________ (low albeto) Negative forces = ________________ Anthropogenic forces are ________________

warming cooling positive

Differentiate between weather and climate, explain their relationship to one another.

weather = day to day conditions climate = long term patterns climate builds on weather