Embed Size (px)
Citation preview
Michigan’s Changing Climate: Recent Past and Projected Future Trends
Jeffrey A. AndresenDept. of Geography
Michigan State University
Mean Temperatures vs. Year, Michigan1895-2010
Mean Winter Temperatures vs. YearIronwood, MI1902-2008
Grand Traverse Bay - Years Frozen by Decade 1851-2006
0
1
2
3
4
5
6
7
8
9
10
Year
s of
Fre
ezin
g
Yrs. BayFroze
Great Lakes Region (32°F threshold)
-10
-5
0
5
10
1895 1915 1935 1955 1975 1995
Year
Fro
st-
Fre
e S
ea
so
n (
da
ys
fro
m n
orm
al)
Length Spring FallSource: K. Kunkel, Midwest. Reg. Clim. Center
Great Lakes Region (1-yr, 1-week)
-100
0
100
200
300
1895 1915 1935 1955 1975 1995
Year
He
at
Wa
ve
Ind
ex
(%
de
via
tio
n)
INTENSE HEAT WAVES
Source: K. Kunkel, Midwest. Reg. Clim. Center
Annual Precipitation vs. Year, Michigan1895-2010
Frequency of Wet Days and Wet/Wet DaysCaro, MI
1930-2008
Great Lakes Region (1-yr, 1-week)
-60
-40
-20
0
20
40
60
1895 1915 1935 1955 1975 1995
Year
He
av
y P
rec
ipit
ati
on
Ind
ex
(%
de
via
tio
n)
FREQUENT HEAVY RAINS FREQUENT HEAVY RAINS
Source: K. Kunkel, Midwest. Reg. Clim. Center
Total Seasonal Snowfall vs. YearBay City, MI1897-2008
Total Seasonal Snowfall vs. YearChatham, MI1901-2008
Annual Number of Days with Snowcover >= 1” vs. Year, Chatham, MI1895-2008
Projecting the Future: Global Climate Models (GCMs)
Natural Variability or Anthropogenic Signal?
(Source: IPCC, 2007)
Source: (IPCC, 2007)
Source: (IPCC, 2007)
Source: (IPCC, 2007)
Model-Projected Mean Temperature DifferencesPontiac, MI 1990-2099
Model-Projected Precipitation RatiosPontiac, MI 1990-2099
Historical and Projected Wheat Yields by Year With and Without CO2 EnrichmentHadCM3 A2 ZS Scenario
Owosso/Pontiac, MI
Impacts of Climatic Variability
• Past history suggests that society will be able to cope/adapt with steady climatic changes, but possibly not with changes in variability (e.g. changes in extremes, storminess)
Summary• Overall, mean average temperatures in Michigan rose
approximately 1.0ºF during the past century. Warming of about 2.0ºF has occurred between 1980 and the present, much of it concentrated during the winter season and at night.
• Milder winter temperatures have led to less ice cover on the Great Lakes and the seasonal spring warm-up is occurring earlier than in the past.
• Annual precipitation rates increased from the 1930’s through the 1990’s but have leveled off recently.
• Most recent GCM simulations of the Great Lakes region suggest a warmer and wetter climate in the distant future, with much of the additional precipitation coming during the cold season months.
• Projections of future climate change in Michigan suggest a mix of beneficial and adverse impacts.
• A changing climate leads to many potential challenges for dependent human and natural systems, especially with respect to climate variability.
Local Coordinators:
