climate change challenges: response of civil engineers · climate change challenges: response of...

Climate Change Challenges:Response of Civil Engineers

Professor Ainun Nishat Ph.D.

Professor Emeritus,

Centre for Climate Change and Environmental Research

BRAC University, Bangladesh1

Presented at Institute of Engineers, Bangladesh March 28 , 2015

• Climate change and climate variability are now real.

• A stable situation is not likely to be achieved soon.

• The IPCC-IV(2007), and now reconfirmed by IPCC-V (2013), concluded that global warming is unequivocally the result of human activities.

• Scientific consensus is clear; collectively, the whole world needs to urgently focus on what to do about it.

• Climate change has risen to the top of global policy agenda. In 2015, we hope see some concrete results in controlling global warming through „legally binding agreement‟ to be enforced by 2020.

Is there any doubt that Climate Change real ?

2


Why the world is worried about Climate Change!

Threat of Food shortage;

Threat of migration; Livelihood insecurity;

Increase in intensity and frequency of natural disasters

Loss of biodiversity and ecosystem

Health security threatened

Process of sustainable development affected

Coping capacity of LDCs, SIDS and countries in Africa is not adequate to cope

3


The Past IS NOT the Future

The Past is the Future

Current Trend

Un-quantified

Risk

March 28, 2015 4


Some Definitions……

Climate Change: any change in climate over time.

Climate variability: variations in the mean state and

other statistics (such as occurrence of extremes, etc.)

of the climate on all temporal and spatial scales.

======================================

Adaptation is a process to cope with the changing

environment..

Mitigation is interventions to reduce the sources or

enhance the sinks of greenhouse gases.

Loss and Damage : the definition is emerging……..

5


Issues in global debate

• CO2 emission has increased from 280 ppm before industrial revolution to about 400 ppm. May reach 600+ ppm by end of this century. Global average temperature is already up by about 1.0c. It may go up to by 6.0c as CO2 concentration goes up.

• Attempts are being made to fix the emission level 450 ppm and then lower it to 350 ppm. Temperature rise be limited to 2.0c and preferably at 1.5 C. Also the peak in emission should be controlled by 2020 and reduced by 80/85% compared 1990 level by 2050.

• Are these likely to be achieved? What were the goals set in Rio in 1992? What were the challenges set out in Bali in 2007? What has been the achievement in Copenhagen/ Cancun/ Durban/ Doha? Will the negotiation be completed and a legally binding Agreement will be finalized and operationalized in Paris in November 2015?

• Will developing countries, specially the Least Developed Countries be able to cope with the adverse impacts of Climate Change and Climate variability?


What is likely to happen

Frequency of extreme climatic events will increase e.g. same location will face floods and drought in shorter frequency;

Intensity of extreme climatic events will increase; e.g. short duration heavy rainfall specially in urban areas

Occurrence of erratic and unusual behaviour of weather will be frequent e.g. rain will occur at unexpected time and will not occur at expected time;

Snow and Ice will melt; in the long run the volume of snow melt water will be very low; threat of GLOF will increase;

Sea Level will rise; to what level is being debated.


Probable adverse impacts

Hydro-meteorological events• Increase in annual rainfall • Increase in droughts • Occurrence of short

duration heavy rainfall• Rainfall at unexpected

time• Rise in temperature• Increase in cyclones and

storm surge events

Other Impacts• Sea level rise

– Increase in salinity in coastal belt

– Inundation of coastal plains

• Snow melting and GLOFs

• Increase in river and coastal erosion

• Increase in vector borne disease

March 28, 2015 8


Goals set out in 1992 through UNFCCC

• Stabilization of the GHG concentrations at a level

that would prevent dangerous anthropogenic

interference with the climatic system.

• Such a level should be achieved within a time

frame sufficient to:

– allow ecosystems to adapt naturally to climate change.

– ensure that food production is not threatened, and

– enable economic development to proceed in a

sustainable manner.


Climate induced hazards

• Recognized globally as one of the most vulnerable (possibly the most vulnerable country) to adverse impacts of Climate Change

• Experiencing the increased frequencies and intensities of natural disasters.– Erratic rainfall.

– Flood with higher intensity

– Cyclones and Tornadoes

– Salinity intrusion

– Tidal surges

– Drought-like phenomenon

– River bank and coastal erosion

– Land Slides


Frequency of severe flood on increase

About 50 m

people

exposed to

severe and

moderate

floods

Floods during

1987, 1988,

1995, 2002,

2004 and

2007

March 28, 2015 12


Urban drainage congestion is on

increase due to heavy rainfall.


Urban drainage congestion is on increase due to heavy rainfall.


River Erosion rate increasing


Coastal zone vulnerability

More frequent rough seas -

Fishermen unable to go to

sea, livelihood under threat.

Salinity increase

Sundarbans: largest

mangrove in Asia under

severe threat


Untimely floods in 2012

(Source: FFWC, 2013)

March 28, 2015 17


Destruction by Cyclone Sidr


Severe Droughts in some places

while other places are Flooded

Presentation at Cornell University August 6, 2011

Impact of AILA


Impact of Aila

Gabura Union, Shyamnagar, Sathakhira: No dry place ….


People migrate from Kalabogi Village, Sutarkahli, Dacope.

Presented at Institute of Engineers, Bangladesh March 28 , 2015March 28, 2015 23


SLR and Salinity

Intrusion


Flood Inundation Depth Map Existing Condition

Land Level (m PWD)

Inundation Depth (m)

7.00-19.004.00- 7.002.00- 4.000.00- 2.00

0.00- 0.15

0.15- 0.30

0.30- 0.60

0.60- 0.900.90- 1.801.80- 3.60

Above 3.60

No Sea Level

Rise

Upstream flow:

Average Year

(Year 2000 flow)

Land Level (m PWD)


7.00-19.004.00- 7.002.00- 4.000.00- 2.00

0.00- 0.15

0.15- 0.30

0.30- 0.60

0.60- 0.900.90- 1.801.80- 3.60

Above 3.60

Upstream flow:

Average Year

(Year 2000 flow)

Land Level (m PWD)


7.00-19.004.00- 7.002.00- 4.000.00- 2.00

0.00- 0.15

0.15- 0.30

0.30- 0.60

0.60- 0.900.90- 1.801.80- 3.60

Above 3.60

Upstream flow:

Average Year

(Year 2000 flow)

Upstream flow:

Average Year

(Year 2000 flow)

Land Level (m) PWD)


7.00-19.004.00- 7.002.00- 4.000.00- 2.00

0.00- 0.15

0.15- 0.30

0.30- 0.60

0.60- 0.900.90- 1.801.80- 3.60

Above 3.60

Land Level (m PWD)


7.00-19.004.00- 7.002.00- 4.000.00- 2.00

0.00- 0.15

0.15- 0.30

0.30- 0.60

0.60- 0.900.90- 1.801.80- 3.60

Above 3.60

Upstream flow:

Average Year

(Year 2000 flow)

Flood Inundation Depth Map: Projection Year 2015

Sea Level Rise 10 cm




Sea Level Rise 32 cmFlood Inundation Depth Map: Projection Year 2100



Short duration heavy rain: Land slides in Chittagong

• Landslides in Chittagong hills

killed 28 people last year (2012),

17 in 2011, 11 in 2008, and 127 in

2007, raising concerns about the

safety of those living in illegal

houses on the hilltops, slopes and

in foothills. Local Authorities have

the reasons behind these issues

are

1. The people do not want to

move out for not having

alternatives.

2. no alternative housing

arrangements so that they

could relocate.

3. influential people with political

blessing grab land, build

houses

Ref: The Daily Star (July 28th, 2013)

March 28, 2015 27


Vulnerability to Flooding


SLR Trends in different points of Bangladesh

Slide 29

3.9 mm/yr

1.4 mm/yr

5.6 mm/yr

The rate of sea level rise is far more than the historical

assessments!

March 28, 2015


Soil salinity

Increasing soil

salinity is pushing the

agrarians from the

coastal zone to

migrate.

One out of every 10

family is migrating!

(Map redrawn based on Survey of

SRDI, 2009)March 28, 2015 30


“ Kadam” in bloom in front of BRAC University;

Photograph taken on 15th December 2012

March 28, 2015 31


Parameters: drought,

flood and cyclone


Role of Engineers for Mitigation

• Efficient management of solid and liquid waste to

reduce methane production;

• Improvement of water and energy efficiency in all

infrastructure;

• Introduction solar irrigation

• Construction of “green building/ structures/

factories” that save heat energy;

• Brick production with lower CO2 emission levels;

• Support increasing „sink‟ for carbon sequestration;

•


Role of engineers in adaptation (1)……

• Consideration of future climatic scenarios in

planning and design of infrastructures

including roads, bridges, buildings, tunnels,

urban centers and township, etc.

• Flood management projects by accounting

for future hydrologic projections;

• Irrigation projects for low and untimely

rainfall situation;

• Preparation for Surges with dykes of higher

height including green belt on the sea-side.



• Upgrade urban drainage to manage short-duration

heavy rain in cities, towns, rural growth centers,

• Effective management of drainage infrastructures;

• Management of storm surges and cyclonic weather

by building dykes, shelters, drainage sluices, etc.

• Prevention of land-slides with slope retention

structures

• River basin management including hydro-power

generation and its distribution and augmentation of

flow in dry season.



• Push for river management infrastructures as river

bank and coastal erosion rates will increase.

• Support rain water conservation, specially in

coastal belt, to support water supply and

sanitation.

• Support climate change induced health hazards

through fighting vector bourne diseases,


Concluding Remarks

• We must prepare for Adaptation to Climate

Variability (the already occurring extreme

events) and keep in mind the trends indicated in

Climate Change forecasts.

• The process of development must not be

compromised.

• Response to floods, droughts, urban drainage

problems, storm surge and cyclones are known

but response to sea level rise and snow and

glacier melting is to evolve.


Concluding Remarks

• We must prepare for Adaptation to Climate Variability(the already occurring extreme events) and keep in mind the trends indicated in Climate Change forecasts. This is very important for all countries specially for the LDCs and Developing Countries.

• Response to floods, droughts, urban drainage problems, storm surge and cyclones are known but response to sea level rise and snow and glacier melting is to evolve.

• We must also push for Mitigation and control of GHG emission level

• The process of development must not be compromised.

• Science is clear; we need political will to achieve success both in Adaptation and Mitigation.


Thank

you for your patience

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