Variaciones del clima de la Ciudad de México durante el siglo XX.

Cities and CC
The city changes the climate and
the climate conditions the city
Adalberto Tejeda Martínez,
Universidad Veracruzana
www.publicacionesatm.blogspot.com
Elda Luyando López
Centro de Ciencias de la Atmósfera, UNAM.
Población en la Ciudad de México.
20000
18000
habitantes x 1000
16000
14000
12000
10000
8000
6000
4000
2000
20
00
19
90
19
80
19
70
19
60
19
50
19
40
19
30
19
21
19
00
0
Mexico’s population
2
Fig. 14. Promedios horarios del balance energético (en Prepa 7, del
1 al 14 de diciembre de 1998).
Q*
350
QH
250
w/m²
QE
150
QS
50
-50
-150
hora local
Hourly average of the
atmospheric/surface
energy balance
components (Texcoco
Lake, August 24,
1999, rural)
Horas
2200
2000
1800
1600
1400
1200
1000
800
Qs
600
Qs, stored soil heat
Qh
400
Qh, sensible heat
QE
200
QE, evaporation
Q*
0
W/m 2
Q*, Net radiation
600
550
500
450
400
350
300
250
200
150
100
50
0
-50
-100
Heat island in Mexico City
Observatorio de Tacubaya
°C
y = 0.0481x + 7.4175
14
12
10
8
6
4
20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80 84 88 92 96 00 04 08
19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 20
Mean annual minimum temperature. Period 1920-2009.
Mexico
City
Observatorio de Tacubaya
°C
y = 0.011x + 23.196
26
25
24
23
22
Mean annual maximum temperature. Period 1920-2009.
08
04
20
00
20
96
20
92
19
88
19
84
19
80
19
76
19
72
19
68
19
64
19
60
19
56
19
52
19
48
19
44
19
40
19
36
19
32
19
28
19
24
19
19
19
20
21
Mexico City
Temperature expected increase to
2030. Various GCM, 1ºC
Population in 2030
in millions
Average heat island
according to 2030
population (expected
maximum increase)
Ciudad de México
22.1
1.7°C
Monterrey
5.0
1.3
Guadalajara
5.4
1.4
Ciudad Juárez
1.8
1.1
Puebla
3.3
1.3
Mexico City
20
18
16
14
12
10
8
6
4
2
0
18
77
-1
88
18
7
88
-1
89
18
8
99
-1
90
19
9
10
-1
92
19
0
21
-1
93
19
0
31
-1
94
19
0
41
-1
95
19
0
51
-1
96
19
0
61
-1
97
19
0
71
-1
98
19
0
81
-1
99
19
0
91
-2
00
20
0
01
-2
01
0
No. de ondas de calor por década
Observatorio de Tacubaya
Number of heat waves (three or more consecutive days > 30°C) per decade.
Period 1877-2010.
Jáuregui, Luyando and Casasola, 2009
Comparativo de los umbrales de clasificación arbitrarios
Número de días
900
800
700
600
500
400
300
200
100
0
32ºC
33ºC
34ºC
35ºC
1931
1940
1941
1950
1951
1960
1961
1970
1971
1980
1981
1990
1991
2000
2001
2006
décadas
Times that Tmax has exceeded the above limit, 1931-2006, Port
of Veracruz.
20
19
19
19
19
19
19
19
19
19
18
18
18
01
91
81
71
61
51
41
31
21
10
99
88
77
Frequency of maximum precipitation in 24 hrs > 30 mm.
-2
0
-2
0
-1
9
-1
9
-1
9
-1
9
-1
9
-1
9
-1
9
-1
9
-1
9
-1
8
-1
8
09
00
90
80
70
60
50
40
30
20
09
98
87
Eventos por década
m
Observatorio de Tacubaya, Ciudad de México.
60
50
40
30
20
10
0
Risks of cities to CC by hydrometeors
(floods, landslides, droughts, heat waves)
Risks = threat x vulnerability x value
Global and local climate change the threat:
probability of occurrence of phenomenon
Uncontrolled urban growth increases
vulnerability
There is no greater value than the human
life
12
Vulnerability of human population
• Year 2000: 680 millions have not adequate water
services, and 850 millions have not toilets.
• In developing countries: 30 to 50% of urban
population in informal settlements.
• Inability of governments, financial failure and distorted
policies
• Antagonisms between government levels
• Deteriorating of governance.
13
Vulnerability of human population
• If slightly abnormal rain (or drought) causes
disasters, the city is NOT in the adaptation process
to climate change
• Concatenated disasters (flooding, pollution, disease,
economic deterioration, etc.).
• Poverty: mainly children, women and seniors.
14
Adaptation measures to climate change
• Scenarios of sea level rise and storm surge (expected
coastlines and settlements).
• Estimates of increases in heat waves, vulnerable
population (elderly) and state of health system
• Drought scenarios diagnosed with potable water system
• Increase of GHG emissions for air conditioning of
buildings (global warming and urban)
Planning and society
a) Inclusion of specific chapters in metropolitan
areas over a million in plans for adaptation to CC
b) Expert advice and support citizens to the authorities,
but with clear agendas and independ
a) ence of analysis and issue recommendations
c) Campaigns without transmission of panic among
younger generations
d) Studies of gender and vulnerable groups to detect
specific adaptation measures
e) Early warning systems with emphasis on human
settlements
Summary
Risks = threat x vurnerability x
value
• Risk levels by hydrometeors
in tropical cities (heat waves,
floods, droughts) are
increasing exponentially in the
time for urban growth (which
impacts the value and
vulnerability) and global
climate change and local
climate change
(increasing threat).