EI Exam 3

Greenhouse effect

Natural process

Greenhouse effect step one

sunlight enters the atmosphere

Greenhouse effect step 2

Energy abosrbed at surface

Greenhouse effect step 3

energy is converted to heat 9infrared radiation)

Greenhouse effect 4

Earth’s surface reheats heat back up

Greenhouse effect 5

Greenhouse gases absorb outgoing radiation

Greenhouse effect 6

Heat is re-radiated back towards earth

What temperature would the earth be without greenhouse gases

0 F

Major greenhouse gases in order from most contributed to least

CO (80), CH4 (11), N2O (7)

Emission volume increases around what percent each year?

3

Sources of CO2 in US form highest to lowest

Transportation, Electric power, industry, residential/commercial, agriculture

What are large carbon sinks?

oceans and plants

How does the ocean absorb CO2

Dissolution in surface water, biological processes… polar waters are especially effective

Too much CO2 in the ocean leads to

acidification

Issues with plant absorbtion of CO2

deforestation, burning releases stored carbon and regrowth is slow

What percent of our glaciers are retreating

85-90

Antarctic ice loss is up how much in recent years

3x

Glacier loss reduces albedo, why is this bad?

Less reflection, more heat absorption

Sea level rise is caused by what percent of meltwater

50%

Due to permafrost melt, siberian temperature has increased up to

5 F

Shifting seasons worldwide examples

Earlier springs, later freeze-over, earlier ice-out, birds don’t fly as far south , butterfly moves upslope, species shifting polward

Increase in hurricane…

frequency, strength, size, water content

Hurricane Catarina (2004) - Brazil

First, and only recorded hurricane-strength storm in the south atlantic (expanding storm zones)

Hurrican Katrina (2005) - New Orleans

One of the deadliest in US history, massive levee failures, vulnerability of coastal infrastructure

Hurricane Sandy (2012) - NJ, NY

Unusual north movement

Hurricane Harvey (2017) - Houston

Record breaking rainfall - 60 in rainfall

Hurricane Maria (2017) - Puerto Rico

Still recovering, long-term infrastructure collapse, power grid failure

Erratic weather as evidence for climate change

California multi-year droughts, longer amazon fire season, indonesian rainforest burning, increased heat waves

Observed trends due to climate change

More record high temperatures, fdwer record low temperatures, more fatalities form heat

General circulation models (GCM’s)

Divide atmosphere, ocean, and land into 3D grid cells

GCM model calculates

energy entering, leaving, heat transfer, moisture movement, cloud formation, ocean heat exchange

GCMs predict

temperature change, jetstream shifts, circulation changes, sea level rise trends… but struggles with small scale

Today’s world if we were to immediately end greenhosue gas emissions

Atmospheric stability by 2050, unavoidable warming by about ~1.1 C

If things continue (business as usual) and emissions continue to increase

by 2060 CO2 levels reach 900 ppm, temperatures increase drastically

“Sustainable world” scenario

emissions stabilize by 2060, 1.2 C warming by 2100

Sea level rise if all greenland ice melted

global sea levels would go up 24 feet

Sea level rise if all antarctic ice melted

180 ft

consequences of 16-24 in of sea level rise

chronic flooding, loss of agriculture, saltwater intrusion into aquifers, infrastructure damage, meltwater form canada could chill europe

Climate belts shift

northward movement of agricultural zones, canada expands growing season, africa would have a short rainy season and the midwest would have a drying risk

wettness pattern shift

drier at low latitude, more intense rainfall events

Health effects of climate change

heat waves; increased mortality… malnutrition, diarrheal, cardiorespiratory illness, vector-borne diseases

+1 degree of warming

coral reefs largely gone, megadroughts in US Plains

+2 degree of warming

95% chance by 2100, ocean acidification threatens marine food chaines, greenland ice sheet destabilized, extreme heatwaves

+3 degree of warming

Arctic summer sea ice gone, hurricanes reach category 6, Amazon becomes savanna

+4 degree of warming

Tipping point for permafrost melting, west antarctic ice sheet threatened, south europe becomes desert

+5 degree of warming

major rainforest collapse, 100 million refuges, sub-tropical areas become uninhabitable

+6 degree of warming

Huge part of earth uninhabitable, mass extinctions, societal collapse

Mitigation strategies for climate change

Policy cahnge+emission caps, economic encentives (carbon taxes, cap and trade markets), adaptations planning

Kyoto protocol (1997)

Imposed emission limits, 92-94% of 1990 level for developed countries, no limits for developing countries

Coppenhagen Climate Change Conference 2009

Target = global reduction of 2% of 1990s levels, non-binding, no consequences, limited success

Paris Agreement 2015

Goal: <2 C warming, carbon neutral by 2060, global review every 5 years, transparency and limited enforcement, urged developed countries to commit money to developing countries

IPCC special report October 2018

1.5 C warming is likely, even with extreme mitigatio. Must cut 45-50% by 2030, net zero by 2050. Renewable energy expanding faster than expeted, fossil fuel use growing again.

Build back better act

$555 billion for climate and environmental justice

Paris agreement US

Trump withdrew in 2016, Biden rejoined, Trump withdrew

Enhancing carbon absorption

DOES NOT reduce emissions, Increase forest cover, soil carbon sequestration

Soil carbon sequestration

Grasses store carbon in deep roots, inexpensive, improve soi lhealth, reduce erosion, BUT limited capacity, reversed by poor land use

Biochar

pyrolysis of organic waste, produces stable carbon rich material

Bioenergy with carbon capture and storage (BECSS)

Uses biomass for fuel/electricity, captures emitted carbon

Enhanced weathering

crush limestone and put on fields, which absorbs carbon, long term carbon storage, mining and grinding require energy

Direct air capture

machines chemically separate CO2 from the air, it is sotred under ground

Ocean fertilization

add iron to stimualte photosynthesis, carbon will stil end in atmosphere

during last glacial maxima

air temp 9-13 F colder, oceans were 4 F colder, massive ice sheets over North America

Tropical deforestation loss

2% of original forest area/year

Commercial logging

75% deforestation

What percent of beef does the US import?

16%

What percent of deforestation is tied to beef production?

20%

Consequences of deforestation

displacement of nature people - hunter gatherers

How many years can tropical soils sustain crops without damage

3-4 years

How many years can tropical soils sustain grazing animals without damage

5-7 years

Deforestation causes a loss of diversity because

Rainforest used to cover 7% of the Earth’s land

What percent of all species were housed in rainforests?

over 50%

Rain forest importance

Genetic bank, 25% of medicine comes from here, biological control

Solution to deforestatino 1

slow population growth

Agroforestry

mixed crop systems, integration of trees and shrubs into crop farming

Solution for deforestation 2

Debt-for-nature swap, NGO’s (organizations (Sierra club)) raise money

Deforestation solution 3

pay for non-development, developed nations pay developing nations not to cut down their trees.

Ecuador Yasuni National Park

extrememly biodiverse, has over 1.7 billion barrels of oil underneath

Why Yasuni is so important

more trees in 1 hectare than all of north america, thousands of insects, and home of many different indigenous people

Yasuni Proposal 2007

Leave the oil underground for compensation, pay $3.6 billion

Yasuni Agreement collapsed

2013-2016, due to $336 mil pledged, donating countries had no perceived benefit

Yasuni 2016

Drilling near park started

Ecotourism

Travel focuses on experiencing natural environments

Problems with ecotourism

Requires workforce training, risk of greenwashing, environmental impacts

What percent of emitted CO2 ends up absorbed by the oceans

25-30%

Step one of ocean acidification

burning of fossil fuels

step two of ocean acidification

CO2 dissolves in seawater

step 3 of ocean acidification

forms carbonic acid (CO2+H2O → H2CO3)

Step 4 of ocean acidification

cabonic acid dissociates (H2CO3 → H+HCO3)

Step 5 of ocean acidification

hydrogen ions lower pH of ocean

Ocean pH in 1800

8.2

Ocean pH now

8.07

By 2100 ocean pH will be

7.8

Impacts of ocean acidification

reduces carbonate availability, organisms need carbonate to build shells

Impacts of ocean acidification on coral reefs

acid dissolves, calcium carbonate skeletons not forming, reef growth slows, reef becomes fragile

Coral reefs support what percentage of marine species

25%

impacts of ocean acidification on seafood

shell forming organisms affects (oysters, scallops, shrimp, lobster, clams)

As pH drops

ocean chemistry shifts, may reduce ability to absorb CO2

If ocean absorbs less CO2

more remains in the atmosphere

invasive species

non-native species introduced into an ecosystem and causes harm