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BIOL 3999: Issues in Biological Science BIOL 3999: Issues in Biological Science

BIOL 3999: Issues in Biological Science - PowerPoint Presentation

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BIOL 3999: Issues in Biological Science - PPT Presentation

GLOBAL CHANGE BIOLOGY Dr Tyler Evans Email tylerevanscsueastbayedu Phone 5108853475 Office Hours MW 10301200 or by appointment Website http evanslabcsuebweeblycom PREVIOUS LECTURE ID: 356645

greenhouse co2 earth climate co2 greenhouse climate earth gases energy gas atmosphere carbon human emissions models effect future economic

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Slide1

BIOL 3999: Issues in Biological Science

GLOBAL CHANGE BIOLOGY

Dr. Tyler Evans

Email:

tyler.evans@csueastbay.edu

Phone: 510-885-3475

Office Hours: M,W 10:30-12:00 or by appointment

Website: http

://evanslabcsueb.weebly.com

/Slide2

PREVIOUS LECTURE

How human systems influence Earth systems

socio-economic development

p

roduction and consumption

r

esource use

ecosystems

climate

g

eochemical cycles

HUMAN SYSTEMS

EARTH SYSTEMS

Global

Change

BiologySlide3

HOW ARE HUMANS INFLUENCING EARTH SYSTEMS?

ALTERING CLIMATE

CLIMATE: refers to the behavior of the atmosphere over a longer period of time, and usually for a large area.WEATHER: refers to the conditions of the atmosphere over a short period of time, such as hours or days, and typically for a local areaSlide4

HOW IS CLIMATE ALTERED?

The power of a process to alter the climate is estimated by its

RADIATIVE FORCING, the change in the Earth's energy balance due to that process.RADIATIVE FORCES may be:POSITIVEe.g. increases in solar output

NEGATIVE

e.g. volcanic eruptions

Balance between positive and negative

radiative

forcing determines climateSlide5

RADIATIVE FORCING CAN BE CAUSED BY HUMAN ACTIVITIES

c

arbon dioxide emitted from the burning of fossil fuel is presently the largest single climate forcing agent, accounting for more than half of the total positive forcing since 1750.Slide6

Prior to the industrial revolution, the carbon cycle was approximately in balance.

SOURCES (add CO

2

)

respiration

SINKS (removes CO

2)p

hotosynthesisoceans

CO2CO2

Carbon dioxide is naturally present in the atmosphere as part of the Earth's carbon cycle (the natural circulation of carbon among the atmosphere, oceans, soil, plants, and animals).Slide7

Since that time humans have become a source of CO2 by releasing the carbon stored in fossil fuels

Currently, inputs of CO2 outpace the ability of the carbon cycle to remove it from the atmosphere

SOURCES (add CO2)respiration

f

ossil fuels

SINKS (removes CO2)photosynthesisoceans

CO2

CO2Slide8

A USEFUL ANALOGYSlide9

CO2 IS ACCUMULATING IN THE ATMOSPHERE

393 ppm in 2013

315 ppm in 1958Slide10

CO2 IS ACCUMULATING IN THE ATMOSPHERE

n

amed fore Charles David Keeling who collected data

b

ased on atmospheric data collected at Mauna Loa, HI

record starts in 1958 and still continues todaylongest continuous record of atmospheric CO2KEELING CURVESlide11

SEASONALITY IN KEELING CURVE

r

eflects seasonal differences in photosynthesis (SINK)

d

eciduous plants shed leaves in winter and respiration outpaces photosynthesis

in summer, photosynthesis outpaces respiration

respiration

photosynthesisSlide12

DOESN’T FULLY EXPLAIN SEASONALITY

w

hen it is winter in Northern hemisphere (i.e. respiration), it is summer in Southern Hemisphere (i.e. photosynthesis). so shouldn’t these differences cancel each other out?

m

ajor difference in percent land cover between Northern and Southern hemispheres

most land in Southern hemisphere is in tropics where very little seasonal variationthis difference is greatest at temperate latitudes, where deciduous forests dominatephotosynthesis in the Northern hemisphere growing season is greater than the amount of CO2 respired during winter in the southern hemisphere

equatorSlide13

HOW DOES CO2 AFFECT CLIMATE?

CO2 is a GREENHOUSE GAS

and contributes to the GREENHOUSE EFFECT

the Sun emits energy that travels to Earth. Because the Sun is very hot, the energy is emitted in high-energy, short wavelengths that penetrate the Earth's atmosphere.Slide14

HOW DOES CO2 AFFECT CLIMATE?

CO2 is a GREENHOUSE GAS

and contributes to the GREENHOUSE EFFECTabout 30% of the Sun's energy is reflected directly back into space by the atmosphere, clouds, and surface of the Earth. The rest of the Sun's energy is absorbed into the Earth's system.Slide15

HOW DOES CO2 AFFECT CLIMATE?

CO2 is a

GREENHOUSE GAS

and contributes to the

GREENHOUSE EFFECT

Because the Earth is cooler than the Sun, the energy is emitted in the form of infrared radiation, at wavelengths longer than the incoming solar energy.Slide16

HOW DOES CO2 AFFECT CLIMATE?

CO2 is a

GREENHOUSE GAS

and contributes to the

GREENHOUSE EFFECT

greenhouse gases in the atmosphere absorb much of the long-wave energy emitted from the Earth's surface, preventing it from immediately escaping from the Earth's system. The greenhouse gases then re-emit this energy, warming the Earth's surface and atmosphere.Slide17

HOW DOES CO2 AFFECT CLIMATE?

CO2 is a GREENHOUSE GAS

and contributes to the GREENHOUSE EFFECT

t

he increase in the concentration of CO2 has amplified the natural greenhouse effect by trapping more of the energy emitted by the Earth. This change causes Earth's surface temperature to increase among other changes.

greenhouse gases have a POSITIVE RADIATIVE FORCE because they absorb energy radiating from Earth’s surface, rather than allowing it to be directly transmitted into space. Slide18

CO2 IS NOT THE ONLY GREENHOUSE GAS THAT AFFECTS CLIMATE

s

everal other greenhouse gases produced by human activities:

METHANE (CH4)

a colorless, odorless non-toxic gas consisting of molecules made up of four hydrogen atoms and one carbon atom.

NITROUS OXIDE(N2O)

is a colorless, non-flammable gas with a sweetish odor, made up of two nitrogen atoms and one oxygen atom

SULFUR HEXAFLUORIDE (SF6)

Human made gas containing one sulfur atom and six fluoride atoms

human sources of greenhouse gases far exceed natural sourcesSlide19

METHANE

methane (CH4) is the second most prevalent greenhouse gas emitted in the United States from human activities.

methane is emitted by natural sources such as wetlands, however over 60% of total CH4 emissions come from human activities.INDUSTRYAGRICULTURE

LANDFILLS

p

rimary source of methane is natural gas

e

nteric fermentation

b

i-product of decaying organic matterSlide20

NITROUS OXIDE

is a colorless, non-flammable gas with a sweetish odor

nitrous oxide is naturally produced in the oceans and in rainforestsglobally, about 40% of total N2O emissions come from human activities:FERTILIZER

NYLON

NITRIC ACID

CARSBURNING ORGANIC MATTER

i

mprove plant

production

a

lso used in fertilizers

formed in catalytic converters

Component of nylonSlide21

SULFUR HEXAFLUORIDE

fluorinated gases have no natural sources and only come from human-related activities

ALUMINIUMSEMICONDUCTORS

t

hese compounds were produced as an alternative to chlorofluorocarbons (CFCs), which were responsible for depleting the ozone layer

i

ronically, these compounds are potent greenhouse gases with long atmospheric lifetimes Slide22

GREENHOUSE GASES THROUGH TIME

CARBON DIOXIDESlide23

GREENHOUSE GASES THROUGH TIME

METHANESlide24

GREENHOUSE GASES THROUGH TIME

NITROUS OXIDESlide25

GREENHOUSE GASES THROUGH TIME

SULFUR

HEXAFLUORIDE

AND RELATED COMPUNDS Slide26

NOT ALL GREENHOUSE GASES ARE CREATED EQUAL…Slide27

ATMOPSHERIC CONCENTRATIONS OF ALL THESE GREENHOUSE GASES ARE INCREASING

2008

economic

crisisSlide28

2008 Global CO2 Emissions

from fossil fuel combustion

and some industrial processes (million metric tons of CO2)

h

alf of emissions are coming from two countries

not corrected for population (i.e. per capita)Slide29

WILL THE TREND OF INCREASING GREEENHOUSE GASES CONTINUE?Slide30

FUTURE GREENHOUSE GAS EMISSION SCENARIOS

Predictions focus on carbon dioxide:

other greenhouse gases track the pattern of CO2CO2 is by far the largest source of greenhouse gases

A CO2 PROBLEM

U.S.A (84%)

WORLD (77%)Slide31

FUTURE CO2 EMISSIONS SCENARIOS

g

oal of developing future emission scenarios is not to predict the futureunderstand what futures are possible and where major points of uncertainty lieinform how present-day decisions will influence a range of possible futuresto develop future emission scenarios and how this will impact climate scientists use MODELS: a mathematical representation of the interactions between human activities and key components of the Earth systems.

FUTURE CLIMATE MODELS

t

o construct climate models, scientists divide each of the Earth's components spatially into a set of boxes. Simple models may have only a few boxes. The most complex models may have more than a hundred thousand.Slide32

CLIMATE MODELS HAVE TWO COMPONENTS:

1.) Earth System Modelsexplore future changes in physical and biogeochemical responses to changing atmospheric composition and

radiative forcinguse mathematical equations based on well-understood principles to depict the behavior of Earth processes in each box.the movement of energy, air, and water are represented as horizontal and vertical exchanges between the boxes. In this way, models represent interactions between different parts of the climate system and the world.Slide33

2.) Integrated Assessment Models

driving forces and responses by humans through changes in technology, economies, lifestyle and policy

explore alternative socio-economic conditions that would result in such future atmospheric composition changes

Integrated assessment models contain three main factors:

CLIMATE MODELS HAVE TWO COMPONENTS:

a. POPULATIONb. URBANIZATIONc. ECONOMIC DEVELOPMENT

m

ore people = more CO2

m

ore urban areas = more CO2

bigger economy = more CO2Slide34

EFFECT OF POPULATION SIZE ON CO2 EMISSIONSSlide35

EFFECT OF ECONOMY ON CO2 EMISSIONSSlide36

INTERNATIONAL PANEL ON CLIMATE CHANGE (IPCC)

international body for the assessment of climate change established by the United Nations and World

Meterological Organization in 1998goal is to provide the world with a clear scientific view on the current state of knowledge in climate change and its potential environmental and socio-economic impacts.

t

housands of scientists from all over the world contribute to the work of the IPCC on a voluntary basis and reflect a range of views and expertiseSlide37

FUTURE CO2 EMISSION SCENARIOS

v

ery rapid economic growth

p

ursue wealth over environment

changes in economic structures

reductions in energy useclean and resource-efficient technologies.Slide38

LECTURE SUMMARY

climate is altered by changes in

radiative forcingcarbon dioxide emitted from the burning of fossil fuel is presently the largest single climate forcing agentinputs of CO2 outpace the ability of the carbon cycle to remove it from the atmosphere

accumulation of CO2 in atmosphere exhibits a distinct seasonal trend

CO2 and other human emissions act as greenhouse gases and contribute to the greenhouse effect.

greenhouse gas emission are tightly linked with economic developmentgreenhouse gases emissions are expected to increase over the next centurySlide39

NEXT LECTURE:

CO2 AND TEMPERATURESlide40

http://www.esrl.noaa.gov/gmd/ccgg/trends/mlo.html

NOAA Earth System Research Laboratory

MORE INFORMATIONhttp://www.ipcc.ch/TRENDS IN CO2 EMISSIONS

IPCC AND EMISSION SCEANRIOS

GREENHOUSE GASES

http://www.epa.gov/climatechange/ghgemissions/Environmental Protection Agency