Using this powerpoint

• I have narrated many of the slides in the notes section of this powerpoint. Please feel free to use this information for educational purposes.

• Useful websites:• www.weatheroutreach.org• https://www.meted.ucar.edu/loginForm.php?

urlPath=broadcastmet/climate&go_back_to=http%253A%252F%252Fwww.meted.ucar.edu%252Fbroadcastmet%252Fclimate%252Fcontent%252Fsec06_01b.htm#

Motivation: Why talk about this?

• This issue is not going away. • Understanding the science helps us

realize what role we play in the solutions to the issue.

Proportion of the U.S. Adult Population in 2009 …

What do Adult Americans Think?

For full report go to: http://www.americanprogress.org/issues/2009/05/6americas.html

Random sample size n=2,129 people

Understanding your Audience

What do Climate Scientists Think? Are humans responsible for observed warming?

Understanding your Audience

What factors have the effect of changing the Earth’s climate?

• Land

• Ocean

• Sun-Earth

• Atmosphere

Changes in Land and Ocean Circulation

What can change climate?

Precession26,000 years

Tilt 41,000 years

Eccentricity 100,000-413,000 years

The Milankovitch cycle, which has caused ice ages and warm periods in the past, is not causing the current changes we observe.

The Milankovitch Cycle

The Sun-Earth relationship

1750-1950: .2°F of warming occurred due to 1% increase in solar output during this period

1950-1970: slightly less output from the sun, led to slight cooling

What can change Earth’s Climate?

Source: NOAA

Data Show:• Solar output approximately steady• Sunlight is not causing the current climate change

Am

ount

of

sunl

ight

(

Wat

ts/m

eter

2 )

1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006

Energy coming from the Sun (1979-2007) (measured at the top of the Earth’s Atmosphere)

Monthly solar data

Average solar data

What can change Earth’s Climate?

Greenhouse Gases

What can change Earth’s Climate?

Greenhouse gases main factors

• Amount and rate of emissions released

• Effectiveness of heat trapping

• Residence time in the atmosphere

What can change climate?

Human caused (anthropogenic) greenhouse gases

What can change climate?

Why focus on CO2?

Amount of CO2

in the atmosphere- highest in 800,000 years

Historical rate: 30 ppm/1000 years

Current Rate: 30 ppm/last 17 years

satelliteobservations

balloondata

sea surfacetemps

permafrost melt

mtn. glacierretreat

polar ice capretreat

continentalice sheet

retreat

tree rings

coral reefcores

oceansediment

cores

ice cores

biological data

cave data

boreholes

How do we know? Rob Gillies slide modified, puzzle images from COMET

Warming

groundobservations

What data do climate scientists use?

The data …How do we know?

Looking at the graph, what can you conclude about 2008 temperatures?a) 2008 was the coolest year since 2000b) 2008 was warmer than any year before 1988c) Global warming has ended, global cooling is occurringd) Temperatures in 2008 are consistent with global warminge) Two years of temperature data are enough to make statements about

global warming

1988 2000

2008

Looking at the graph, what can you conclude about 2008 temperatures?a) 2008 was the coolest year since 2000b) 2008 was warmer than any year before 1988c) Global warming has ended, global cooling is occurringd) Temperatures in 2008 are consistent with global warminge) Two years of temperature data are enough to make statements about

global warming

Global average temperature changes in 2008

• Temperatures around the globe are not uniform

• One area does not give us the whole picture

• One time does not give us the whole pictureTemperature differences

Te

mp

era

ture

Diff

ere

nce

(°C

)co

mpa

red

to th

e y

ear

20

00

Image Courtesy: Dr. David Chapman

Why should we care?• Only a few degrees means:

– National Security Threatened – Health Impacts – Negative Effects on Economics – Hotter Summers/Warmer Winters– Drought and Floods– Sea-Level Rise– Extreme Weather– Ocean Ecosystems Stressed– Regional Impacts

Only a few degrees?

• Last Ice Age: 7-13°F cooler

125,000 years ago: 1°F warmer, sea levels were 20ft higher

Why should we care?

Decreased water availability and increasing drought in mid-latitudes and semi-arid low latitudesIncreased damage from floods and stormsIncreasing fire risk Increased coastal flooding Up to 30% of species at increasing risk of extinction Significant extinctions

Energy Security/ Independence

Water

Increased water availability in moist tropics and high latitudes

Decreased water availability and increasing drought in mid-latitudes and semi-arid low latitudes

Hundreds of millions of people exposed to increased water stress

Food Productivity of all cereals decreases at low latitudes and in some other regions productivity decreases

Complex, localized negative impacts on subsistence farmers and fishers Tendencies for cereal productivity

to decrease in low latitudes and increase at mid-to high latitudes

Coasts

Increased damage from floods and stormsAbout 30% of global

Millions more people could

coastal wetlands lost

experience coastal flooding each year

Health

Increasing burden from malnutrition, diarrheal, cardio-respiratory and infectious diseasesIncreased morbidity and mortality from heat waves, floods, and droughtsChanged distribution of some disease vectors

Substantial burden on health services

Figure Modified from the IPCC Report SPM.2. Impacts will vary by extent of adaptation, rate of temperature change, and socio-economic pathway.

0°F 1.8°F 3.6°F 5.4°F 7.2°F 9°F

Key Impacts as a function of Increasing Global Average Temperature Change

Global mean annual temperature change relative to 1980-1999

Ecosystems

Significant extinctions around the globe

Up to 30% of species at increasing risk of extinction

Increased coral bleaching Most corals bleached Widespread coral mortalityIncreasing species range shifts

Increasing wildfire risk

Decreased water availability and increasing drought in mid-latitudes and semi-arid low latitudesIncreased damage from floods and stormsIncreasing fire risk Increased coastal flooding Up to 30% of species at increasing risk of extinction Significant extinctions

Energy Security/ Independence

Water

Increased water availability in moist tropics and high latitudes

Decreased water availability and increasing drought in mid-latitudes and semi-arid low latitudes

Hundreds of millions of people exposed to increased water stress

Food Productivity of all cereals decreases at low latitudes and in some other regions productivity decreases

Complex, localized negative impacts on subsistence farmers and fishers Tendencies for cereal productivity

to decrease in low latitudes and increase at mid-to high latitudes

Coasts

Increased damage from floods and stormsAbout 30% of global

Millions more people could

coastal wetlands lost

experience coastal flooding each year

Health

Increasing burden from malnutrition, diarrheal, cardio-respiratory and infectious diseasesIncreased morbidity and mortality from heat waves, floods, and droughtsChanged distribution of some disease vectors

Substantial burden on health services

0°F 1.8°F 3.6°F 5.4°F 7.2°F 9°F

Ecosystems

Significant extinctions around the globe

Up to 30% of species at increasing risk of extinction

Increased coral bleaching Most corals bleached Widespread coral mortalityIncreasing species range shifts

Increasing wildfire risk

1.8°F

stabilization

2×CO2

2.5×CO2

3×CO2 Up to 9.72°F

Warming by 2090-2099 relative to 1980-1999 for non-mitigation scenarios (Modified figure: SPM7 IPCC Report 2007)

Your bills• Heating and Cooling

– $$$ Hotter summers– $ Warmer Winters

• Water Bills– $$$ Drought and

Floods

• Cost of food– $$$ Sea Level Rise– $$$ Crop failures

Why should we care?

Our Bills

• $$$ Extreme Weather

• $$$ National Security

• $$$ Tourism

Why should we care?

Crops and Climate

• USDA predicts faster growth in grain/oil seed crops, but more prone to failure if precipitation decreases.

Why should we care?

Crops and climate

• Earlier plant growth increases vulnerability to spring cold spells

• April 2007 frost cost: $ 2 Billion in agricultural losses

Why should we care?

Food SupplyWhy should we care?

Climate Change and National Security

“National Security and the Threat of Climate Change” 2007, CAN

Corporation

“Global Climate Change: National Security Implications” 2008, U.S. Army War College

“National Intelligence Assessment on the National Security Implications

of Global Climate Change to 2030” 2008, Deputy Director of National

Intelligence for Analysis

Why should we care?

Human health-heat waves more frequent and intense

Why should we care?

During heat waves death rate increases by 6%

Good news in the winter

• Warmer winters – less flu

Why should we care?

Milder temperatures = expanded range for many disease carriers

Why should we care?

Dengue hemorrhagiic fever first appeared in U.S.: 2005 – tropical borne disease

Experts worry that malaria could reappear

Air Pollution Worsens

Why should we care?

Higher humidity and warmer temperatures leads to more ozone and particulate matter forming and lasting longer

Air Pollution Worsens

• 1,000 more air-pollution-related deaths per year for every 1.8°F increase.

Why should we care?

Western US Climate Change• Most of the western US is

warming faster than the global average

• Other climate trends across most of the Western US in the past 50 years include– Longer frost-free growing

season– Earlier and warmer spring– Earlier flower blooms and leaf

out for several plant species– Earlier spring snowmelt and

runoff– Greater fraction of spring

precipitation falling as rain instead of snow

Utah Climate Change

• Last decade was 2°F warmer than the 100 year average

• Snow surveys show no clear long-term (80 year) trend in

mountain snowpack

• There is no clear linkage between recent global warming and precipitation within the basin of the Great Salt Lake

Utah Temperature (°F) 1895-2006

45

46

47

48

49

50

51

52

1895

1905

1915

1925

1935

1945

1955

1965

1975

1985

1995

2005

Line: 10 year running meanSource: National Climatic Data Center

Utah Temperature (°F) 1895-2006

45

46

47

48

49

50

51

52

1895

1905

1915

1925

1935

1945

1955

1965

1975

1985

1995

2005

Line: 10 year running meanSource: National Climatic Data Center

Projected Temperature Change

• Greater warming– In the Arctic– Over land than ocean– In winter than summer

• It is likely that Utah will warm more than the global average

• Projected warming for Utah (2.5xCO2 scenario) is 8°F by 2100– Comparable to the present difference in annual mean temperature

between Park City (44°F) and Salt Lake City (52°F)

Projected Precipitation Changes

• Less confidence in precipitation projections

• Mid and high latitudes wetter

• Most of subtropics drier

• Utah in the transition zone

Utah Snowpack and RunoffDecline in Utah’s mountain snowpack

and associated changes to spring runoff

• Expected trends– Reduced natural snowpack and snowfall

for the winter recreation industry in the early and late winter

– Earlier and less intense spring runoff for reservoir recharge

– Increased demand for agricultural and residential irrigation

– Warming of lakes and rivers with impacts such as increased algal abundance and upstream shifts of fish habitat

Utah Water Supplies and Drought

• It is more likely than not that water supplies in Utah and the Colorado River Basin will decline during the 21st century

– More definitive projections not possible at the present time

• The threat of severe and prolonged drought far worse than observed in the 20th century is real and ongoing

– Megadroughts have occurred in the past

Utah Agriculture

• Based solely on climate change, per-acre crop yields in Utah will likely increase on irrigated fields provided

– Water remains available for irrigation

– Temperatures do not increase beyond crop tolerance levels

http://www.uacd.org/districts/north_cache/programs/programs.htm

• Pasture yields and livestock forage will likely decline on non-irrigated fields

Other Utah Impacts• Great Salt Lake: Declines in

mountain snowpack will likely lead to lower average lake levels and increased average salinity unless average winter precipitation increases dramatically

• Human Health: Increased ground-level ozone concentrations and associated cardio-respiratory disease if non-climatic factors (e.g., emissions) do not change

• Wildfire: In isolation, expected climate change is likely to contribute to drier conditions and increased wildfire intensity

• http://www.cbsnews.com/stories/2007/10/18/60minutes/main3380176.shtml?source=search_story

Other Global Climate Trends• Mean sea level rose 7 inches in the

20th century

• Shrinkage of mountain glaciers, ice caps, and the Greenland ice sheet responsible for 35-40% of the rise since 1993

• Little or no long term trend in the average number of tropical cyclones per year

• Increasing financial losses from hurricanes due to the ever-growing concentration of population and development in coastal regions