CE 401

Climate Change Science and Engineering

modeling of climate changepredictions from models

21 February 2021

team selection and project topic proposal (paragraph): due TODAY 2/21

poster project due Thursday - electronically

exam on first half of class: 3.1.2012

some pre-warned questions for the exam on the 1st :

• what is the average global percent increase in [CO2]/yr since 1959?

• what is the solar energy input [w/m2] at the top of the Earth’s atmosphere?

• what is the average albedo of the Earth [%]?

• what is the solar cycle variability in solar output measured at top of Earth’s atmosphere? [%]

• how many degrees [°C] is the Earth warmer with greenhouse gases than without?

• what ~ percent of global carbon emissions stays in the Earth’s atmosphere?

• what is the pre-industrial (1750) level of [CO2] [ppm]?

• what is the current level of [CO2] [ppm]?

• the carbon cycle

• where does CO2 come from and where does it go

• key components of the climate system

• what goes into a climate model

• what are feedback mechanisms

•

where are we in the syllabus: latest version always on website

source: IPCC 2007 The Climate System - very complicated

components of the system

speeds in the system

modeled global temperature changes from various [CO2] changes

feedbacks are important and modify “normal” models significantly

Figure 8.14

climate feedback parameters: WV=water vapor, C=cloud, A=albedo,LR=lapse rate,

summary of model results for feedbacks

IPCC

Salawitch

the models

Figure 9.1

components of modeled global temp change 1890-1990 (a) solar forcing, (b) volcanoes, c)GHG, (d) tropospheric and stratospheric ozone changes, (e) sulphate aerosol forcing,(f) sum of all forcings, for 1000mb to 10 mb, 0 - 30 km.

pressureheightabovesurface

solarvolcanoes

GHG ozone

sulphate aerosol total

relative radiative forcings 1890 – 1990 from models

what does the IPCC have to say about models and the past 100 years

detection and attribution of causes

basis for attribution of causes for climate change:

• detection: process of demonstrating that climate has changed in some definedstatistical sense, without providing a reason for that change

• attribution of causes: process of establishing the most likely causes for the detectedchange with some defined level of confidence.

Figure 8.5a) observed meanannual precip (cm)for 1980-1999

b) multi-model meansame time period

do predictions agreewith observations

precipitation – obsvd & modeled

IPCC

Observations

Natural + Human-induced

With human-induced influenceWith human-induced influence

Observations and Model ComparisonTemperature Change, 1900 - Present

Natural

Without human-induced influenceWithout human-induced influence

black = observations red = modeled natural + human blue = modeled natural alone

influence of anthropogenic and natural radiative forcings in models:

• significant cooling due to aerosols is a robust feature of a wide range of detectionanalyses

• GHG by themselves would have caused more than the observed warming

• high variance between models - how to identify the aerosol fingerprint (short life)

• using nearly any solar model shows that solar forcing cannot match the observed change

• nonlinearities are not understood (e.g. do forcings just add - most assume this)

synthesis of observed & modeled climate changes – IPCC 2007

IPCC statements on Detection

“little observational evidence of a detectable human influence on climate”

1990 Report

“The balance of evidence suggests a discernible human influence on global climate” 1995 Report

“There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities”, “warming over the 20th century is very unlikely to be due to internal variability alone as estimated by current models”

2001 Report

“the observed widespread warming of the atmosphere and ocean, together with icemass loss, support the conclusion that it is extremely unlikely that global climatechange of the past 50 years can be explained without external [human] forcing, and very likely that it is not due to known natural causes alone.”

2007 Report

basis for attribution of causes for climate change:• detection: process of demonstrating that climate has changed in some defined

statistical sense, without providing a reason for that change• attribution of causes: process of establishing the most likely causes for the detected

change with some defined level of confidence.

this is the “scientific” consensus, is it right?

I have been dismayed over the bogus science and media hype associated with the (dangerous) human-induced global warming hypothesis. My innate sense of how the atmosphere-ocean functions does not allow me to accept thesescenarios. Observations and theory do not support these ideas. (Professor Emeritus William Gray, CSU, 2006)

Predictions of harmful climatic effects due to future increases in hydrocarbon use and minorGHG like CO2 do not conform to current experimental knowledge, Robinson et al, 2007

On the most important issue, the IPCC’s claim that “most of the observed increase in global average temperatures since the mid-twentieth century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations [emphasis in theoriginal],” NIPCC reaches the opposite conclusion — namely, that natural causes are very likely to be the dominant cause. Non-governmental International Panel on ClimateChange (NIPCC - http://www.nipccreport.org/)

contrarians

Climate Projections for the 21st century

(based on the models)

Revelle and Suess (1957): “human beings are now carrying outa large scale geophysical experiment of a kind that could nothave happened in the past nor be reproduced in the future. Within a few centuries we are returning to the atmosphere and oceans the concentrated organic carbon stored in sedimentary rocks over hundreds of millions of years”

Singer , Hot Talk, Cold Science (1997): Industrialized nationsare poised to adopt policies that will cost hundreds of billions of dollars “to mitigate disasters that exist only on computer printouts and in the feverish imaginations of professional environmental zealots”

results of the models – the predictions and the assignment of cause - are a verypolarizing issue

the models use a set of economic scenarios, from “business as usual” = just keep ramping up carbon useage (A2), to models that take into account economic changes to a service/inofrmation based economy with reductions inmaterial intensity and use of clean and resource-efficient technologies (B1)

scenario assumptions:• fossil fuel use• population change• economic growth• technological innovation• attitudes to social and environmental sustainability• land use change

Figure 10.4

multi-model means of surface warming relative to 1980-1999 for various scenarios.Shading shows 1 std dev range. B1, A1B, A2 are low, med, hi scenarios. # givenumber of models run into that period

various scenarios of warming based on various economic models

IPCC 2007

Figure 10.12

multimodel mean changes for A1B scenario – 2090 relative to 1990

extreme events:• increased risk of more intense, more frequent and longer lasting heat waves

• decrease in the diurnal temp range in most regions

• fewer frost days

• longer growing season

• increased summer dryness and winter wetness in NH midlats and high lats

• increase in extreme rainfall intensity

• evidence that future tropical cyclones could be come more severe

as it usually appearsin print - not adjustedfor a baseline $$ - andin Al Gore’s film

same data adjustedfor a baseline $$

IPCC 2007

Projected changes in annual temperatures for the 2050s

The projected change in annual temperatures for the 2050s compared with the present day, when the climate model is driven with an increase in greenhouse gas concentrations equivalent to about 1% increase per year in CO2

BW 11

source: GISS

-30%-10 0 10+30%

South Florida: 1-m rise in Sea Level

Change in January Average Daily Maximum Temperature (doubling of CO2)

source: Hotchkiss and Stone (2000)

Change in July Average Daily Precipitation (doubling of CO2)

source: Hotchkiss and Stone (2000)

Present

CO2 doubling

by 2050

Vegetation Changes for Modeled Doubling of Carbon Dioxide

source: IPCC, 1996

Temperate forests

Grasslands

Deserts

Savanna

Tropical seasonalforest

Tropical moistforest

Ice

Tundra

Boreal forests

Color Code: now

x 2 CO2

Changescurrent --> 2050

Peak 8-Hr Ozone [ppbv]

(EPA Standard = 80 ppbv)

WSU/LAR - Lamb et al.

Current

Difference

Future

ozone air pollution

differencedifference

Precipitation increases very likely in high latitudes

Decreases likely in most subtropical land regions

winter summer

Regional Climate ModelingPacific NW

• temp increases: 2.2F/2025, 3.5F/2045, 5.9F/2080• April 1 snowpack down by 30% across state by 2025, down 40% by 2045

• primary impact on Puget Sound will be a shift in the timing of peak river flowfrom late spring to late winter• shorter irrigation season• annual hydro production will decrease by a few %

• reservoir systems will likely be less able to supply water to all users – 30% by 2025• due to increased summer temps, area burned by fire is expecdted to double by 2045• rising stream temps will likely reduce quality and extent of salmon habitat• warming is expected during all seasons• sea level increases 2-13 inches by 2100• projected changes in annual precipitation averaged over all models are small (1-2%)• impact of climate change on crops will be mild in short term with increasing effects

• yields of dry land wheat will increase 2-8% by 2025

a quick look at global energy sources and projected demand

Change in CO2 Emissions from Coal (2007 to 2009)

Global Carbon Project 2010; Data: Gregg Marland, Thomas Boden-CDIAC 2010

92% of growth

-50

0

50

100

150

200

250

300

China USIndia World

CO2 e

miss

ions

(Tg

C y-1

)

350

global energy production by type

greenhouse gas emissions

global GHG emissions (anthropogenic)

to 2004

Fossil Fuel CO2 Emissions: Top Emitters

Global Carbon Project 2010; Data: Gregg Marland, Tom Boden-CDIAC 2010

1990 95 2001 05 200997 99 03930

400

800

1200

1600

2000Ca

rbon

Em

issio

ns p

er y

ear

(C to

ns x

1,0

00,0

00)

China

USA

Japan

Russian Fed.India

07

2009

Time (y)

Top 20 CO2 Emitters & Per Capita Emissions 2009

Global Carbon Project 2010; Data: Gregg Marland, Thomas Boden-CDIAC 2010; Population World Bank 2010

0

500

1000

1500

2000

2500

CHINAUSA

INDIA

RUSSIAJA

PAN

GERMANYIRAN

SOUTH KOREA

CANADA

UNITED KINGDOM

MEXICO

SAUDI ARABIA

SOUTH AFRICA

INDONESIAITALY

BRAZIL

AUSTRALIA

FRANCE (inl. M

onac

o)

POLAND

SPAIN0

1

2

3

4

5

6

Tota

l Car

bon

Emiss

ions

(to

ns x

1,0

00,0

00)

Per Capita Emissions

(tons C person y-1)

Human Perturbation of the Global Carbon Budget

Global Carbon Project 2010; Updated from Le Quéré et al. 2009, Nature Geoscience; Canadell et al. 2007, PNAS

5

10

10

5

1850 1900 1950 2000

2000-2009(PgC)

atmospheric CO2

ocean

land

fossil fuel emissions

deforestation

(Residual)

Sink

Sour

ce

Time (y)

CO2 f

lux

(PgC

y-1)

2.3±0.4(5 models)

4.1±0.1

7.7±0.5

1.1±0.7

2.4

ppp=purchasing power parity

toe per capita

1971 - 2003 by region; mtoe = million tonnes of oil equivalent

Who has the oil?USA

China

India

(http://www.energybulletin.net/37329.html)

Total global energy demand

70%increase

(International Energy Outlook 2006)

Energy use by type

(International Energy Outlook 2006)

Fossil Fuel Emissions: Actual vs. IPCC Scenarios

Updated from Raupach et al. 2007, PNAS; Data: Gregg Marland, Thomas Boden-CDIAC 2010; International Monetary Fund 2010

Foss

il Fue

l Em

issio

n (Pg

Cy-1)

5

6

7

8

9

10

1990 1995 2000 2005 2010 2015

Full range of IPCC individual scenarios used for climate projections

A1B Models AverageA1FI Models AverageA1T Models AverageA2 Models Average

B1 Models AverageB2 Models Average

ObservedProjected

Time (y)