ss 2008 luka jakelja, stefan krase, christian kozina the impacts of climate change 1 how climate...

SS 2008 Luka Jakelja, Stefan Krase, Christian Kozina

The Impacts of Climate Change

1

How Climate ChangeWill Affect People Around The World

The Impacts of Climate ChangeStern Review, Chapter 3

Luka Jakelja, Stefan Krase, Christian KozinaThe Economics of Climate Change, SS 2008



2

Key message

“Climate Change threatens the basic elements of life for people all around the world – access to water, food,

health, and use of land and the environment.“



3

Table of contents

1. Introduction

2. Impacts on the water availability

3. Impacts on the food production

4. Impacts on the human health

5. Impacts on the use of land

6. Impacts on the infrastructure

7. Impacts on the environment

8. Non-linear changes and treshold effects

9. Summary and conclusion



4

1. Introduction









Table of contents



5

1. Introduction

„The consequences of climate change will depend on how the physical impacts interact with socio-

economic factors.“



6

1. Introduction

(IPCC FAR, 2007)



7

1. Introduction

IPCC scenarios

A1

B2B1

A2 economic growth

sustainability

global local (IPCC FAR, 2007)



8

1. Introduction

IPCC scenarios

A1

B2B1

A2 economic growth

sustainability

global local (IPCC FAR, 2007)



9

1. Introduction

IPCC scenarios

A1A1 T

A1 B

A1 Fl

non-fossil energy sources

balanced use

intensive use of fossil energy sources

(IPCC FAR, 2007)



10

1. Introduction

IPCC scenarios

Global sustainability (~ + 1.8°C)- population peak in mid-century, then decline- rapid change in economic structures

Global economic growth (~ + 2.8°C)- population peak in mid-century, then decline- rapid introduction of new technologies

National enterprises (~ + 3.4°C)- continiuously increasing population- econ. development regionally oriented

A1 B

B1

A2



11

1. Introduction

“The consequences of climate change will become disproportionately more damaging with increased

warming.“



12

1. Introduction

Relation between air temperature …

… and water holding capacity of the air.

exponential

y = ex



13

1. Introduction


… and extrem temperatures.

convex

(IP

CC

TA

R,

20

01

)



14

1. Introduction


… and storm damage.

cubic

y = x3



15

1. Introduction

There are two effects, that are not usually included in existing studies (do not consider 5-6 °C warming):

1. More extreme weather events: disproportionately increase

2. Non-linear effects and treshold-effects: become increasingly severe at higher temperatures (chapter 8)

The combined effect of impacts across several sectors could be very damaging and amplify the consequences of climate change.



16

1. Introduction









Table of contents



17


Meaning of water

• essential ressource for all life

• requirement for good health and sanitation

• input for almost all production

• essential for sustainable growth and poverty reduction

People will feel the impact of climate change most strongly through changes in the distribution of water around and its seasonal and annual variability.



18


Intensification of the water cyle

• droughts and floods become more severe in many areas

• more intense rainfall

• more rain in high latitudes

• less rain in the dry subtropics

• probably substantial changes in tropical areas

As a result, several billion people will be living in areas of more limited water avialability.



19

Changes in precipitation




20


Increase in annual river flows is not necessarily beneficial:

• Not enough storage to hold the extra water

• More serious flooding during the wet season

More crucial in dry reagions:

• Risk of droughts 40 % of land area (today 10 %) for + 3-4 °C

• Risk of extreme droughts 30 % (today 3 %)



21


Melting glaciers and loss of mountain snow:

• Meltwater needed during the long run dry season disappears permanently once the glacier has melted

• Risk of damaging glacial lake outburst

• Ganges: meltwater from glaciers = 70% of summer flow (!)

• India: 500 million peopleChina: 250 million peopleSouth America: tens of millions in the Andes

• All in all it threatens about 1/6 of the worlds population!



22

1. Introduction









Table of contents




Some Facts about agriculture:

accounts for 24% of world output

employs 22% of the global population

uses 40% of the land area

1 billion relies on agriculture (= people who live on less than 1 Dollar a day)

23




What are the Impacts:

Warming may improve growth

extend / shift growing seasons

increasing damage when reaching peak temperatures more often

Damage to crops because of windthrow, wildfires, soil erosion, waterlogging of soils

24




Impacts depend on:

Temperature

Location

Carbon fertilization

25



26


Temperature andlocation:

Source: http://www.globalwarmingart.com/wiki/Image:Annual_Average_Temperature_Map_jpg




Crop Productivity is projected to increase slightly at mid- to high latitudes (mean temp. increases of 1-3°C

At lower latitudes, especially is projected to decrease for even small temp. Increases (1-2°C)

Globally, potential for food production is projected to increase (temp. increases 1-3°C) above it will decrease

27




Carbon fertilization:

CO2 is a basic builing block for plant growth.

Able to offset waterstress and increasing temperatures in some extent

Earlier studies claimed that a concentration of 550 ppm CO2 leads to increases in crop yields of 20-30%

Recent studies showed that a concentration of 550ppm CO2 increases crop yields by just up to 8-15% (if CO2 responsive)

28




Impacts on regions (food):

Europe:

Especially the situation in southern Europe is projected to worsen (high temperatures and droughts). This region is already vulnerable to climate variability and water availability.

Africa:

By 2020, in some countries, yields from rain-fed agriculture could be reduced by up to 50%

By 2080, increase of arid & semi arid land of 5% to 8%

29



Relation of temperature and crop yield

• is not symmetrical

• it is distinctly asymmetricfairly flat at first and thensharply declining beyondan upper threshold

Source: Schlenker and Roberts (2006)


30



1. Introduction









31

Table of contents




What are the impacts:

Increase of malnutrition

Increase of Heat stress

Increase of vector-borne diseases (malaria, dengue fever)

Cold related deaths decrease

32



Peak temperatures may already be at the limit at some locations

Northern latitude countries will suffer less deaths in winter

1-3mio more die from malnutrition (+3° + low carbon fertilization)

40-60mio more people exposed to malaria in Africa (+2°)

WHO expects that 150 000 die p.a. because of climate change --> will double at just +1°C

33




34




35


Estimates of extra deaths (per mio people) from climate change



1. Introduction









36

Table of contents




Some Facts:

• More than 200 mio live in coastal floodplains with 2 mio km2 and 1 trillion worth of assets (less than 1m elevation above current sea level)

• 22 of 50 major cities are at risk of flooding

• Even if protected, residual risk of flooding like New Orleans

The homes of tens of millions more people are likely to be affected by flooding from coastal storm surges with rising sea levels

37



• Although protection level rises in line with GDP per capita additional people willbe flooded every year (figure)

• Warming of 3-4°C will lead to 20-80cm rise of sea level

• Upgrading coastal defences could partially offset these impacts

• Costs of upgrading rise exponentially with required height

• Today nearly as many political refugees compared to environmental ones

• Some estimates project that 150-200 mio people may become permanently displaced by the middle of the century due to rising sea levels, more frequent floods and more intense droughts.

38




39




1. Introduction









40

Table of contents




Cimate change will increase the intensity of storms, with impacts on:

Soil conditions• Droughts• Permafrost melting

Wind• Windspeed as an exponential function of temperature• Damage costs as a cubic function of windspeed

41



Source: Stern 2007


42



Some facts:

• Storms and associated flooding are the most costly natural disaster

• Causing 90% of the total losses from natural catastrophes

• With a large proportion in the developed world


43



1. Introduction









44

Table of contents



7. Impacts on the Environment

In the past:

• Species mooving polewards 6km/decade

• Decline of species (polar bear, caribou, white sprouce)

• 1% of world‘s amphibian species from tropical mountains

• Since 1500, 245 species extincted

• Today 800 species are threatened with extinction

45



EXCURSUS: What is a caribou?

Well…

46




Climate change occurs too rapidly for many species to adapt …

2°C warming:

• 15-40% of species facing extinction

• High risk of extinction of arctic species

• Irreversible bleaching of coral reefs

• Loss of vast ares of tundra and forest

47




3°C warming:• 20-50% of species facing extinction

• 25-60% mammals• 30-40% birds• 15-70% butterflies in South Africa

• Onset of Amazon forest collapse• Losing large areas of wetlands caused by rising see levels

4 or 5°C warming:

Full range of consequences not clear yet

48



1. Introduction









49

Table of contents



8. Non-linear changes and threshold effects

• Increasing chances of abrupt and large-scale changes

• Shifts in regional weather patterns (with consequences for water availability in tropical regions)

• Melting/collapse of polar ice sheets will have impacts on:• Population• Land area• GDP

50




Impacts of melting/collapse of polar ice sheets:

Sour

ce:

Ster

n 20

07

51




Source: Stern 2007

Potential temperature triggers for large-scale and abrupt changes in climate system:

52




53

Tipping pointsin the earthsystem

Source: Edenhofer 2007



1. Introduction









54

Table of contents



9. Summary and Conclusions

„Climate change will have increasingly sever impact on people around the world, with a growing risk of abrupt

and large-scale changes at higher temperatures.“

55



56

Thank you!



57

Questions

How will climate change affect people around the world (overview)?

What are the further consequences, when living conditions are getting worse?1



58

Questions

What are the basics for projections of future changes in climate (szenarios)?

What must be considered? 2



59

Questions

Why will the consequences of climate change become disproportionately more damaging with increasing warming?3



60

Questions

Climate change will alter patterns of water availability by intensifying the water circle.

What does it lead to? Are there real benefits for any countries?4



61

Questions

What is the main problem about melting glaciers and loss of mountain snow?

What is the main reason for sea level rise? What does it lead to?5



62

Questions

Will climate change increase worldwide deaths?

Are there any benefits for health? 6



63

Questions

What is maybe the most crucial fact regarding shifts in regional weather regimes such as changes in monsoon or the El Niño? 7



64

Questions

It is argued that with temperatures rising more and more species are threatened. What is the actual problem about this? One might argue that it is not a big thing that scuba diving at the Great Barrier Reef will not be that much fun anymore without the corals … 8

ss 2008 luka jakelja, stefan krase, christian kozina the impacts of climate change 1 how climate...

Documents