So What?

The Climate is Changing . . .

Overview

• The “worldview” on climate change

• Zoom in on Michigan

• Will it affect ME?

General trends

• Temperature increases: 4°F to 7°F by 2100

• Precipitation will increase in some places, and decrease in others

• Sea levels will rise

• Extreme weather events will be more frequent

WORLDWIDE

WORLDWIDE

• increasing ground instability in permafrost regions, and rock avalanches in mountain regions

• warming of lakes and rivers in many regions, with effects on thermal structure and water quality

• earlier timing of spring events, such as leaf-unfolding, bird migration and egg-laying poleward and upward shifts in ranges in plant and animal species

• range changes and earlier migrations of fish in rivers http://www.ipcc.ch/publications_and_data/ar4/wg2/en/contents.html

IPCC says:

IPCC says:

WORLDWIDE

• Most of the observed increase in the globally averaged temperature since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.

• Of the more than 29,000 observational data series, from 75 studies, that show significant change in many physical and biological systems, more than 89% are consistent with the direction of change expected as a response to warming.

http://www.ipcc.ch/publications_and_data/ar4/wg2/en/contents.html

Socioeconomic Effects

WORLDWIDE

• effects on agricultural and forestry management at Northern Hemisphere higher latitudes, such as earlier spring planting of crops, and alterations in disturbance regimes of forests due to fires and pests

• some aspects of human health, such as heat-related mortality in Europe, infectious disease vectors in some areas, and allergenic pollen in Northern Hemisphere high and mid-latitudes

• In the Sahelian region of Africa, warmer and drier conditions have led to a reduced length of growing season with detrimental effects on crops. In southern Africa, longer dry seasons and more uncertain rainfall are prompting adaptation measures

• Sea-level rise and human development are together contributing to losses of coastal wetlands and mangroves and increasing damage from coastal flooding in many areas

WORLDWIDE

http://www.news.wisc.edu/11878

• coastlines along the Pacific and Indian oceans and sub-Saharan Africa • large sprawling cities, with their urban "heat island" effect

Third World bears brunt of global warming impacts

So . . .

• Michigan is OK, then . . .

Right?

What climatic changes have YOU noticed?

• Warmer– Extreme heat will be more common – Nighttime temperatures are expected to warm more than

daytime temperatures • Drier overall– Average precipitation levels are unlikely to change, but the

seasonal patterns of precipitation will vary greatly• increasing in winter• decreasing in the summer

http://www.ucsusa.org/greatlakes/glimpactmigrating.html

General TrendsMICHGAN

Some DetailsWarmer Temperatures A 5-10oF rise in winter and a 7-13oF rise in summer temperatures by the end of the century is projected.

Precipitation Changes Although average annual precipitation may not change much, an overall drier climate is expected because rainfall cannot compensate for the increase in evaporation resulting from greater temperatures. Thus Michigan may see drier soils and more droughts. Seasonally, winter precipitation is expected to increase by 5-25% while summer precipition is expected to remain the same.

Extreme Events Extreme heat will be more common, and the frequency of heavy rainstorms will increase and could be 50-100% higher than today.

Growing Season The growing season could be 8-10 weeks longer.

Ice Cover Declines in ice cover on the Great Lakes and inland lakes have been recorded over the past 100-150 years and are expected to continue.

MICHGAN

But will it affect ME?

What is a Cooling Degree Day?

• Unit relating temperature to energy demand

• Used for comparisons, weather derivatives

• Every degree Fahrenheit the average daily temperature increases above 65˚F– Let’s see an example…

M T W T F S S

Avg. Temp 70˚F 88˚F 90˚F 95˚F 84˚F 87˚F 90˚F

# Degrees Above 65˚F

70 – 65 =

5

88 – 65 = 23

90 – 65 = 25

95 – 65 = 30

84 – 65 = 19

87 – 65 = 22

90 – 65 = 25

Cooling Degree

Days 5 23 25 30 19 22 25

5 + 23 + 25 + 30 + 19 + 22 + 25 = 149 total cooling degree days for this week

Discussion Questions

• Briefly describe the patterns you see in each scenario. How are conditions predicted to change over time?

• Are the predicted changes consistent with patterns you observed this summer? Why might there be differences?

• What are some ways you might be affected (both directly and indirectly) by the predicted changes?

• Will longer growing seasons automatically mean more crops? What other changes could affect productivity?

http://www.pileus.msu.edu