Horizon Net Zero Dawn – keynote slides by Ben Abraham
Regional Climate Simulations Project
1. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Agriculture and Climate
Change
Eugene S. Takle
Agronomy Department
Geological and Atmospheric Science
Department
Iowa State University
Ames, Iowa 50011
gstakle@iastate.edu
Underwriting/Marketing Seminar, 30 March 2005
2. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Outline
Evidence for global climate change
Future atmospheric carbon dioxide concentrations
Simulations of global climate and future climate
change
Impacts of climate change for the US Midwest
“Climate surprises”
Social inequities and ethical issues
surrounding climate change
Summary
9. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Associated Climate Changes
Global sea-level has increased 1-2 mm/yr
Duration of ice cover of rivers and lakes decreased by 2 weeks in N.
Hemisphere
Arctic ice has thinned substantially, decreased in extent by 10-15%
Reduced permafrost in polar, sub-polar, mountainous regions
Growing season lengthened by 1-4 days in N. Hemisphere
Retreat of continental glaciers on all continents
Poleward shift of animal and plant ranges
Snow cover decreased by 10%
Earlier flowering dates
Coral reef bleaching
Source: Intergovernmental Panel on Climate Change, 2001 Report
10. Mann, M. E., R. S. Bailey, and M. K. Hughes, 1999: Geophysical Research Letters 26, 759.
25. IPCC Summary for
Policy Makers
An increasing body of observations gives a
collective picture of a warming world and
other changes in the climate system
26. IPCC Summary for
Policy Makers
An increasing body of observations gives a
collective picture of a warming world and
other changes in the climate system
Emissions of greenhouse gases and aerosols
due to human activities continue to
alter the atmosphere in ways that
are expected to affect the climate
27. IPCC Summary for
Policy Makers, cont’d
Confidence in the ability of models to
project future climate has increased
28. IPCC Summary for
Policy Makers, cont’d
Confidence in the ability of models to
project future climate has increased
There is new and stronger evidence that
most of the warming observed over
the last 50 years is attributable
to human activities
29. IPCC Summary for
Policy Makers, cont’d
Anthropogenic climate change will persist
for many centuries
30. IPCC Summary for
Policy Makers, cont’d
Anthropogenic climate change will persist
for many centuries
Further action is required to address
remaining gaps in information and
understanding
31. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Climate Surprises:
Low Probability but High-Impact Events
Breakdown of the ocean thermohaline
circulation (Greenland melt water)
Breakoff of the West Antarctic Ice Sheet
34. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Meltwater flows into
a large moulin on
Greenland and down to
the bedrock to "lubricate"
the sheet
BBC News: World Edition
http://news.bbc.co.uk/2/hi/science/nature/2558319.stm
35.
36.
37. For the Midwest
Warming will be greater for winter than summer
Warming will be greater at night than during the
day
A 3oF rise in summer daytime temperature triples
the probability of a heat wave
Growing season will be longer (8-9 days longer
now than in 1950)
More precipitation
Likely more soil moisture in summer
More rain will come in intense rainfall events
Higher stream flow, more flooding
38. Sub-Basins of the
Upper Mississippi
River Basin
119 sub-basins
Outflow measured
at Grafton, IL
Approximately one
observing station
per sub-basin
Approximately one
model grid point
per sub-basin
42. Ten-Year Mean Monthly Stream Flow Generated by the
RegCM2 Regional Climate Model Driven
with HadCM2 Global Model Results for the
Contemporary and Future Scenario (2040s) Climate
43. Relation of Runoff to Precipitation
for Various Climates
More precip
goes to
streamflow in a
future climate
46. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Social Inequities due to Climate
Change
Agricultural production
Freshwater availability
Sea-water innundation
Intergenerational equities
47. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Social Inequities due to Climate
Change
Agricultural production
Freshwater availability
Sea-water innundation
Intergenerational equities
48.
49.
50. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Impact on US Agriculture
(my speculations)
The US is a large enough country at a high enough latitude that it will have
regional winners and losers
Areas now marginal for agriculture may become less suitable
Some areas now having abundant water but limited growing seasons may be
winners
Areas with good soils and robust climate, like Iowa, may be impacted less
The US Midwest may experience more variability from
year to year, which would make agricultural yields
more variable (flooding, water-logging, drought)
Changes in consumption and agricultural production
in other nations may affect US agriculture more
than changes to US climate
Environmental refugees?
51. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Social Inequities due to Climate
Change
Agricultural production
Freshwater availability
Sea-water innundation
Intergenerational equities
54. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Social Inequities due to Climate
Change
Agricultural production
Freshwater availability
Sea-water innundation
Intergenerational equities
56. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Sea-Water Innundation
Example: The Maldives
Area: 115 square miles
Population: 143,000
Highest point: 20 ft above sea level
57. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Social Inequities due to Climate
Change
Agricultural production
Freshwater availability
Sea-water innundation
Intergenerational inequities
58. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Intergenerational Inequities
Sustainable Development: “To meet the needs of
the present without compromising the ability of
future generations to meet their needs.”
Energy sources?
Non-renewable earth resources?
Agricultural productivity?
Fresh water supplies?
Heavy metal contamination of soil
and water?
59. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Summary
Climate change is real and we need to be doing
something about it
The longer we wait, the fewer our options
Regional patterns of warming will be complicated
Climate surprises can’t be discounted
Climate change will create regional
agricultural winners and losers
Climate change carries ethical
implications
60. PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
For More Information
See my online Global Change course:
http://www.meteor.iastate.edu/gccourse
Contact me directly:
gstakle@iastate.edu
http://www.meteor.iastate.edu/faculty/takle/
Hinweis der Redaktion
From Jerry Meehl
This slide shows the time evolution of globally averaged surface air
temperature from multiple ensemble simulations of 20th century climate
from the NCAR Parallel Climate Model (PCM) compared to observations.
The simulations start in the late 19th century, and continue to the year
2000. The temperature scale at left is in degrees Centigrade, and
temperature anomalies are calculated relative to a reference period
averaged from 1890 to 1919. The black line shows the observed data, or
the actual, recorded
globally averaged surface air temperatures from the past century. The
blue and red lines are the average of four simulations each from the
computer model. The pink and light blue shaded areas depict the range
of the four simulations for each experiment, giving an idea of the
uncertainty of a given realization of 20th century climate from the
climate model. The blue line shows the average from the four member
ensemble of the simulated time evolution of globally average surface air
temperature when only "natural" influences (solar variability and
volcanic eruptions) are included in the model. Therefore, the blue
line represents what the model says global average temperatures would
have been if there had been no human influences. The red line shows the
average of the four member ensemble experiment when natural forcings AND
anthropogenic influences (greenhouse gases including carbon dioxide,
sulfate aerosols from air pollution, and ozone changes) are included in
the model. Note that this model can reproduce the actual, observed data
very well only if the combined effects of natural and anthropogenic
factors are included. The conclusion that can be drawn is that
naturally occuring influences on climate contributed to most of the
warming that occurred before WWII, but that the large observed
temperature increases since the 1970s can only be simulated in the model
if anthropogenic factors are included.
This confirms the conclusion of the IPCC Third Assessment Report that
most of the warming we have observed in the latter part of the 20th
century has been due to human influences.
A feature that corresponds to later 20th century trends. Not seen in GCMs. Linked to mesoscale circulation.