Transcript doubling of CO 2

CE 401
Climate Change Science and Engineering
modeling of climate change
predictions 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

 components of the system
speeds in the system 
source: IPCC 2007
The Climate System - very complicated
modeled global temperature changes from various [CO2] changes
feedbacks are important and modify “normal” models significantly
summary of model results for feedbacks
Figure 8.14
climate feedback parameters: WV=water vapor, C=cloud, A=albedo,LR=lapse rate,
IPCC
Salawitch
the models 
relative radiative forcings 1890 – 1990 from models
solar
volcanoes
Figure 9.1
pressure

height
above
surface
GHG
sulphate aerosol
ozone
total
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.
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 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.
precipitation – obsvd & modeled
Figure 8.5
a) observed mean
annual precip (cm)
for 1980-1999
b) multi-model mean
same time period
do predictions agree
with observations
IPCC
Observations and Model Comparison
Temperature Change, 1900 - Present
With human-induced influence
Without human-induced influence
Observations
Natural +
Human-induced
black = observations
red = modeled natural + human
Natural
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 detection
analyses
• 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



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.
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 ice
mass loss, support the conclusion that it is extremely unlikely that global climate
change 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
this is the “scientific” consensus, is it right?
contrarians
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 these
scenarios. 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 minor
GHG 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 the
original],” NIPCC reaches the opposite conclusion — namely, that natural causes are
very likely to be the dominant cause. Non-governmental International Panel on Climate
Change (NIPCC - http://www.nipccreport.org/)
Climate Projections
for the 21st century
(based on the models)
results of the models – the predictions and the assignment of cause - are a very
polarizing issue
Revelle and Suess (1957): “human beings are now carrying out
a large scale geophysical experiment of a kind that could not
have 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 nations
are 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”
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 in
material 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
various scenarios of warming based on various economic models
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. # give
IPCC 2007
number of models run into that period
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 appears
in print - not adjusted
for a baseline $$ - and
in Al Gore’s film
same data adjusted
for a baseline $$
IPCC 2007
Projected changes in annual temperatures for the
2050s
source: GISS
BW 11
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
-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)
Vegetation Changes for Modeled Doubling of Carbon Dioxide
Present
now
Color Code:
Temperate forests
Grasslands
Deserts
Savanna
Tropical seasonal
forest
Tropical moist
forest
CO2 doubling
by 2050
Ice
Tundra
Boreal forests
source: IPCC, 1996
x 2 CO2
Current
Changes
current --> 2050
Future
ozone air pollution
Peak 8-Hr Ozone [ppbv]
(EPA Standard = 80
ppbv)
WSU/LAR - Lamb et al.
Difference
difference
winter
summer
Precipitation increases very likely in high latitudes
Decreases likely in most subtropical land regions
Regional Climate Modeling
Pacific 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 flow
from 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)
350
CO2 emissions (Tg C y-1)
300
250
92% of growth
200
150
100
50
0
China
India
US
-50
Global Carbon Project 2010; Data: Gregg Marland, Thomas Boden-CDIAC 2010
World
global energy production by type
greenhouse gas emissions
global GHG emissions (anthropogenic)
to 2004
Fossil Fuel CO2 Emissions: Top Emitters
2009
China
1600
(C tons x 1,000,000)
Carbon Emissions per year
2000
USA
1200
800
India
Russian Fed.
400
Japan
0
1990
93
95
97
99
2001 03
Time (y)
Global Carbon Project 2010; Data: Gregg Marland, Tom Boden-CDIAC 2010
05
07
2009
2500
(tons x 1,000,000)
1500
5
4
3
1000
500
0
Global Carbon Project 2010; Data: Gregg Marland, Thomas Boden-CDIAC 2010; Population World Bank 2010
2
1
0
Per Capita Emissions
2000
6
(tons C person y-1)
Total Carbon Emissions
Top 20 CO2 Emitters & Per Capita Emissions 2009
Human Perturbation of the Global Carbon Budget
2000-2009
(PgC)
10
Source
7.7±0.5
5
deforestation
atmospheric CO2
Sink
CO2 flux (PgC y-1)
fossil fuel emissions
land
5
ocean
2.4 (Residual)
2.3±0.4
(5 models)
10
1850
1.1±0.7
4.1±0.1
1900
1950
Time (y)
Global Carbon Project 2010; Updated from Le Quéré et al. 2009, Nature Geoscience; Canadell et al. 2007, PNAS
2000
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 Emission (PgCy-1)
Fossil Fuel Emissions: Actual vs. IPCC Scenarios
10
9
Observed
Projected
A1B Models Average
A1FI Models Average
A1T Models Average
A2 Models Average
8
B1 Models Average
B2 Models Average
7
Full range of IPCC
individual scenarios
used for climate
projections
6
5
1990
1995
2000
2005
Time (y)
Updated from Raupach et al. 2007, PNAS; Data: Gregg Marland, Thomas Boden-CDIAC
2010; International Monetary Fund 2010
2010
2015