Slides for GGR 314,Global Warming

Chapter 7: Heat and Water Stress,Terrestrial Species Extinctions

Course taught by

Danny HarveyDepartment of Geography

University of Toronto

Exhibit 7-1: Regions currently with water stress

Source: IPCC AR4 WG2, Chapter 3, Fig. 3.2

Source: Barnett et al. (2005, Nature, Vol. 438, 303-309)

Exhibit 7-2: Ratio of annual snowfall to annual runoff. The red line outlines the areas where runoff is predominantly from snowmelt and

there is not adequate storage to buffer seasonal variations.

Source: Barnett et al. (2005, Nature, Vol. 438, 303-309)

Exhibit 7-3: Retreat of the Gangotri glacier in the Himalayas

Source: IPCC AR4 WG4, Chapter 10, Fig. 10.6

Exhibit 7-4: Recent retreat of some Himalayan glaciers

Source: IPCC AR4 WG2, Chapter 10

Exhibit 7-5: Projected change in annual river runoff, 2050 compared to the 1961-1990 average

Source: Arnell et al (2011, Glob. Env. Change, Vol. 21, 592-603)

Exhibit 7-6: Numbers of people in different regions in 2050 experiencing an increase (top) or decrease (bottom) in water stress (<1000 m3/P/yr) based on climate projections by the same 4 AOGCMs featured in Exhibit 7-5.

Source: Arnell et al (2011, Glob. Env. Change, Vol. 21, 592-603)

Exhibit 7-7: Projected changes in annual river runoff; links to water and sustainable development

Source: IPCC AR4 WG2, Chapter 3, Fig. 3.8

Recall: Exhibit 4-5: Projected global mean temperature change for a business-as-usual scenario compared to variations during the previous

millennium and observed changes during the past 150 years, neglecting likely positive climate-carbon cycle feedbacks.

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1000 1200 1400 1600 1800 2000 2200

Year

Te

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Pessimistic Projection

Optimistic Projection

ObservedVarious Inferred Variations

Source: Harvey (2010, Energy and The New Reality, Vol 1, Earthscan, Fig. 1.5)

Exhibit 7-8: Distribution of maximum wetbulb temperature (Tw) that occurred at any time during the decade 1999-2008. The warmest Tw to

have occurred anywhere is about 30oC.

Source: Sherwood and Huber (2010, Proc. Nat. Acad. Sci., Vol. 107, 9552-9555)

Exhibit 7-9: Maximum annual Tw as simulated by an AGCM-ML ocean model after the global mean temperature has warmed by 10oC relative

to 1999-2008.

Source: Sherwood and Huber (2010, Proc. Nat. Acad. Sci., Vol. 107, 9552-9555)

Exhibit 7-10: Histograms showing the frequencies of different surface air temperatures for all time steps and grid points (black), maximum surface air temperatures at all grid points (blue), and maximum Tw values (red) as observed during the decade 1999-2008 (left) and as simulated after a global mean warming of 10oC (right). The red dashed curve in the right chart is the Tw distribution shown in the left chart for the 1999-2008 decade. The vertical dashed line is the absolute maximum Tw value (35oC) that humans can survive.

Source: Sherwood and Huber (2010, Proc. Nat. Acad. Sci., Vol. 107, 9552-9555)

Exhibit 7-11: Maximum mammal body size was a factor of 1000 smaller than today 70 million years ago, when temperatures were 5-7oC warmer. Cooling over the past 50 million

years (inferred from the data in the lower panel) made it easier to dissipate heat as the mass of the largest mammals increased during the past 70 million years and the

surface:volume ratio decreased. Mammals about 20 times less massive than the largest found today survived the PETM 55 million years ago

100 80 60 40 20 0

Age (millions of years)

Source: Smith et al (2010, Science, Vol. 330, 1216-1219)

Exhibit 7-12: Frequency distribution of departures of individual summers from the 1900-2006 average summer temperature, for the 1900-2006 time period (observed) and as projected for 2080-2100 (frequencies in each case are adjusted to represent 100 summers)

Source: Battisti and Naylor (2009, Science, Vol. 323, 240-244)

Exhibit 7-13: Frequency of summers in 2040-2060 that are warmer than the warmest summer on record (1900-2006)

Source: Battisti and Naylor (2009, Science, Vol. 323, 240-244)

Exhibit 7-14: Frequency of summers in 2080-2100 that are warmer than the warmest summer on record (1900-2006)

Source: Battisti and Naylor (2009, Science, Vol. 323, 240-244)

Exhibit 7-15: Average change (oC) in summer temperature in Europe, as simulated by 6 different high-resolution regional climate models

driven by 3 different AOGCMs, for 2071-2100 compared to 1961-1990.

Source: Fischer and Schar (2010, Nature Geoscience, Vol. 3, 398-403)

Exhibit 7-16: Ratio of number of heat waves per year in 2021-2050 (left) and 2071-2100 (right) to the number in 1961-1990 (a heat wave is defined as a spell of at least 6 consecutive days where the maximum temperature

exceeds the local 90th percentile for the 1961-1990 period).

Source: Fischer and Schar (2010, Nature Geoscience, Vol. 3, 398-403)

Exhibit 7-17: Increase in the temperature of heat waves during 2021-2050 (left) and 2071-2100 (right) compared to heat waves during 1961-

1990.

Source: Fischer and Schar (2010, Nature Geoscience, Vol. 3, 398-403)

Exhibit 7-18: Average daily maximum temperature during JJA for the 1961-1990 period (top) and numbers of days per year with maximum

temperature > 35oC and minimum night-time temperature > 25oC

Source: Lelieveld et al. (2012, Climatic Change, in press)

Exhibit 7-19a: Probability distribution of hourly temperature for the 1961-1990 period and as projected for 2010-2039 (orange), 2040-

2069 (red) and 2070-2099 (magenta)

Source: Lelieveld et al. (2012, Climatic Change, in press)

Exhibit 7-19b: Probability distribution of hourly temperature for the 1961-1990 period and as projected for 2010-2039 (orange), 2040-

2069 (red) and 2070-2099 (magenta)

Source: Lelieveld et al. (2012, Climatic Change, in press)

June 2006

August 2006 following a July heat wave

Exhibit 7-20a: Heliotropium convolvulaceum on a Mojave Desert Sand-dune

Photos by R. Sage, University of Toronto

Exhibit 7-20b: Opuntia cacti in the Mojave DesertAugust 2006 following a July heat wave.

The injury patterns are unusual and indicate severe stress

Photos by R. Sage, University of Toronto

Exhibit 7-20c: Cacti injured by heat stress Healthy cacti

Photos by R. Sage, University of Toronto

Exhibit 7-21a: Tundra vegetation near lower elevation limit showing evidence of dieback in the cushion plantEriognomum ovalifolium. White Mountains, California.

Photo by R. Sage, University of Toronto

Exhibit 7-21b: Healthy tundra. White Mountains, California.

Photo by R. Sage, University of Toronto

Exhibit 7-22: Impact of projected global warming (top) and increasing GDP per capita (bottom) on the incidence of malaria. Net result: malaria decreases

everywhere

Source: Beguin et al (2011, Glob. Env. Change, Vol. 21, 1209-1214)

Exhibit 7-23: Increase in the incidence of malaria (red) if GDP per person decreases by 50% (with an unchanged % of GDP devoted to

health and sanitation)

Source: Beguin et al (2011, Glob. Env. Change, Vol. 21, 1209-1214)