The document discusses how climate change will impact cities through increased temperatures, more extreme precipitation events, and sea level rise. It provides projections for temperature increases and precipitation changes in North America. Cities will experience more heat waves that may be exacerbated by urban heat islands. Coastal cities are particularly at risk from sea level rise. Effective adaptation strategies are needed to reduce risks and increase resilience of cities.

1. Climate Change & Cities
James Voogt
Department of Geography
Western University
President: International Association for Urban Climate

2. CO2–Now above 400 ppm
280
Pre-industrial CO2level

3. Where are we going?
RCP = “Representative Concentration Pathways”
To keep temperature change <2°C relative to pre-industrial levels requires atmospheric concentrations in 2100 of about 450ppm CO2eq (high confidence)
These scenarios include substantial cuts in anthropogenic GHG emissions by mid-century.

4. How will climate change?
IPCC AR5 WG1 (2013)
Near term warming –all scenarios
Increasing rate of warming –high emissions scenarios

5. Temperature Projections: North America
IPCC WG1 2013
High Emissions
Low Emission
IPCC: Warming in the Great Lakes region is projected to be about 50% greater than that of the global mean warming; more warming further north; mean warming over land will be larger than over the ocean (very high confidence)

6. Projected Hot Days
MOE (2009)
IPCC AR5: “a current 20-year high temperature event will occur more frequently by the end of the 21st century (at least doubling its frequency, but in many regions becoming an annual or two-year event) and a current 20-year low temperature event will become exceedingly rare”
Toronto
Urban Impact: Shift in demands for cooling (increases) and heating (decreases)

7. Trends in the Number of Annual Heat Wave Days
Smith et al. (2013)
15 Heat Wave Indices and their change 1979-2011
Days per Year
Data suggest heat waves are already increasing
Very Likelyto change further by late 21stCentury

8. Heatwaves and Cities
The urban heat island can magnify heat wave effects
Toronto
Russian Heat Wave: 70,000 deaths
European Heat Wave: 55,000 deaths
Heat is the deadliest of weather hazards (US Data)

9. Future Climates and Heatwaves
Schäret al. (2004)
the probability of a summer experiencing mega- heatwaves will increase by a factor of 5 to 10 within the next 40 years
Chicago: Deaths from heat waves per year for 7 climate models run for 3 emissions scenarios
Peng et al. (2010)
Higher temperatures in polluted regions trigger feedbacks that increase ozone and particulate matter pollution

10. Precipitation
Evaporation increases in a warmer world
Warmer air contains more moisture
IPCC WG1 AR5 2013
High Emissions Scenario
RCP 8.5
Low Emission Mitigation ScenarioRCP 2.6

11. Precipitation in North America
IPCC WG1 2013
High latitudes –more precipitation
Subtropics –decreases in precipitation

12. Change since 1950 in Top 1% Heaviest Rainfall Events
US National Climate Assessment (2013)
IPCC: likelyincreases in either frequency or intensity of heavy precipitation

13. Extreme Precipitation
High moisture content in atmosphere
Polewardmovement of storm tracks
IPCC: Over most of the mid-latitude land masses extreme precipitation will very likely be more intense and more frequent in a warmer world
The Canadian Press / Winston Neutel
Toronto Rain Event 2013
Ontario’s most costly “natural” disaster
$850 million -insured losses
$1.2 billion –estimated total losses

14. TELLING THE WEATHER STORY | 14
By 2050, a 1990’s 1-in-20 year annual maximum daily precipitation amount is likely to become a 1-in-10 year event.
ABOUT TWICE AS MANY HEAVY SUMMER STORMS.
More heavy precipitation events in 2050
Toronto Rain –2005 -$624 m
Calgary Rain/Wind –2010 –$1B
Calgary Rain/Wind –2009 –$362 m
SW Ontario Rain/Wind –2009 –$482 m
Calgary Hail –1991 –$885 m

15. CBC

16. Flooding
High River AB, June 23, 2013 (REUTERS/Andy Clark)
Character of rainfall is changing: more intense; overall precipitation less frequent
Spatial changes to precipitation
More precipitation from extratropicalcyclones in winter
Hydrology changes –timing/amount of runoff
Human modifications

17. TELLING THE WEATHER STORY | 17
Severe Weather
Goderich Tornado: Aug 21 2011(AP/CP/Geoff Robins)
A trend towards environments that favour more severe thunderstorms

18. Fires in BC
MONTHS OF IMPACT
$5B + DAMAGES
30+ DEATHS
Ice Storms
1998 Eastern Canada Ice Storm
2013 Southern Ontario Ice Storm
$200 million in insured losses
Alex Urosevicfor National Post
“by 2046-2065, days with freezing rain are projected to increase by 35% to 55% for Toronto and Windsor, by 50% to 70% for Montreal and Ottawa, and by 70% to 100% for Kenora, Thunder Bay, and Timmins.” Canada in a Changing Climate 2014

19. CurrentClimate
Futurescenario
City[D=Cityonadelta]
Population in 2005
Exposedpopulation
Exposedassets
Exposedpopulation
Exposedassets
Mumbai,India
18.2
2.8
46
11.4
1598
Guangzhou,China[D]
8.4
2.7
84
10.3
3358
Shanghai,China[D]
14.5
2.4
73
5.5
1771
Miami,USA
5.4
2.0
416
4.8
3513
HoChiMinhCity,Vietnam[D]
5.1
1.9
27
9.2
653
Kolkata,India[D]
14.3
1.9
32
14.0
1961
NewYork-Newark,USA
18.7
1.5
320
2.9
2147
Osaka-Kobe,Japan[D]
11.3
1.4
216
2.0
969
Alexandria,Egypt[D]
3.8
1.3
28
4.4
563
NewOrleans,USA[D]
1.0
1.1
234
1.4
1013
Tokyo,Japan[D]
35.2
1.1
174
2.5
1207
Tianjin,China[D]
7.0
1.0
30
3.8
1231
Bangkok,Thailand[D]
6.6
0.9
39
5.1
1118
Dhaka,Bangladesh[D]
12.4
0.8
8
11.1
544
Amsterdam,Netherlands[D]
1.2
0.8
128
1.4
844
Sea Level Rise: Top 15 world port cities ranked by population exposure under the current climate and future climate scenario.
Population –millions; Exposed Assets: $US billions
Nicholls et al (2008)

20. EFFECTIVE CLIMATE CHANGE ADAPTATION
A MORE VIBRANT WORLD

21. More than half the global population now lives in urban areas and this is increasing (64-69% by 2050).
In 2006, urban areas accounted for 67 –76 % of energy use and 71 –76 % of energy-related CO2emissions.
Urban-Global Links CO2
Data from UN in Okeet al. forthcoming

22. It is important to see the urban climate effect as embedded in the general climate. The accumulated contributions of all the cities of the world does have an impact on global climates. Changes in the global/regional climates have an affect on cities.
Cities and Climate Change
Mills (2010)

23. GHG Emissions Vary with Climate and City Layout
Oke et al. (forthcoming)

24. Surface Controls on Urban Climates
Photo: J. Voogt
Form: Geometric structure
Land Cover(impervious, vegetated)
Metabolism (emissions of water, heat, pollutants)
City Size
Materials(radiative, thermal, moisture, aerodynamic)

25. At the building scale:
Solar radiation management
Shading
Reflectance (surface properties)
Greater use of daylighting
Facilitation of air movement
Application of urban vegetation: roof and walls
Application of water
Building material properties
On-site generation of energy

26. Where we are going: a (sobering) update
Friedlingsteinet al. (2014)
“Two thirds of the CO2emission quota consistent with a 2°C temperature limit has already been used, and the total quota will likely be exhausted in a further 30 years at the 2014 emissions rates.”
The window of opportunity to limit global average warming to < 2°C is rapidly closing. Significant mitigation efforts are needed immediately.

27. Take Home Messages
Anthropogenic climate change is occurring and effects will become more clear with time
Cities are important sites related to both emissions of GHG (climate forcing) and receiving impacts of climate change
Urban areas further modify climates: e.g. water balance changes and heat islands that exacerbate climate change in cities
More compact and densely occupied cities generally generate less GHG per capita. Policies to reduce emissions in cities should consider technology and fuel-switching, but also the potential for moderating the urban contribution of GHG through more efficient urban form, transport and land-use mix.

28. Risk Level withCurrent Adaptation
Potential forAdditional Adaptation to Reduce Risk
Risk Level withHigh Adaptation
Risk-Level
VeryLow
Med
VeryHigh
4°C
2°C
Present
Long Term(2080-2100
Near Term (2030-2040
Increased Risksfrom Wildfires
Heat-RelatedHuman Mortality
Damages from River and Coastal Urban Floods
NORTH AMERICA
IPCC North America: Risks

29. Pledges to Emissions Cuts made in Durban 2011
ClimateActionTracker.Org(as shown in Tollefson2011)

30. emissions
concentrations
temperature
sea level
IPCC (2002)
Climate Change Commitments

32. A summary of the tools/strategies (in black) employed at the building, building group and settlement scales to achieve climatic objectives at those scales. The application of tools at each scale has a climate impact at (red), and places limits on decisions made at (blue), the other scales.
Urban Scales, climate objectives and design tools
Objective Impacts Limits Buildings Building Groups Settlement Indoor comfort Shelter Buildings Location Materials Design (e.g. shape, orientation, etc.) Access to light, solar energy, wind. Air quality Building codes Outdoor comfort Outdoor health Building groups Local climate change: Emissions Materials/surfaces Building dimensions – flow interference & shadow areas Building placement. Outdoor landscaping, materials and surfaces. Street dimensions & orientation Guidelines on Densities Heights Uses Green-spaces Energy use Air quality Protection from extremes Settlement Energy efficiency Air quality Urban climate effect Mode and intensity of traffic flows. Energy efficiency Air quality Urban climate effect Zoning Overall extent and shape. Transport Policy