DHAKA, the capital of Bangladesh, and one of the fastest growing cities of the world, has been infamous for a while for being over-populated, traffic congested, waterlogged (urban flooding) and polluted (e.g. toxic waste, poor sewage system, harmful emissions, etc.). In less than 325 square kilometres of area, it supports more than 15 million people which makes it one of the most densely populated megacities. It has grown from a provincial town into a megacity after the independence in 1971. But the infrastructures, organisations and the systems inevitably could not cope up with the astonishing growth.

Dhaka has seen lots of changes in the urban mobility scenario, policies and regulations with their implications in the last 40 years. Motorisation was, and still is, quite low but the congestion is increasing due to various reasons. The number of non-motorised vehicles (NMVs) has increased by almost eight or ten folds; compressed natural gas (CNG) has been introduced; plan for mass rapid transit (MRT) systems and waterways, and phasing out of rickshaws have been going on; and a 20-year transportation master plan, Strategic Transport Plan (STP), has been proposed (which was recently revised).

Also, a trend of preference towards private vehicles (e.g. personal cars, motorbikes, etc.) from the late 90s till present has also been observed. A phenomenon which is not unprecedented in developing cities. One of the main reasons behind this trend in Dhaka is the lack of effective public transport and near non-existence of urban rail. The present state of affairs results in serious congestion in the whole traffic network of the city.

As a consequence of the horrendous traffic situation, air quality has deteriorated significantly. It used to be termed as the most polluted city in the world in the 90s because of the presence of high level of lead in air (coming from the emissions of the vehicles). Pollution from traffic and brick kilns had been identified as two of the most significant factors by various studies. In order to improve this severe situation, the authorities took some steps (e.g. banning two-stroke engines, introducing CNG, etc.). But there has been little systematic research on air pollution in Dhaka resulting from traffic but some estimations of emission from different sectors (e.g. transport, industry, residential) are available.

In spite of few projects in the 90s and 2000s, air quality monitoring data is still rare and mostly unavailable due to limited measuring facilities, economic constraints, and lack of initiatives. Bangladesh has Environment Conservation Rules (1997) and it developed an Air Quality Index (AQI) in around 2005 based on National Ambient Air Quality Standards (NAAQS) of the US (the AQI value runs from 0 to 500). The higher the AQI value, the greater the level of air pollution and health concerns. On February 17, 2014, Dhaka's air quality was measured at 172 AQI which is considered unhealthy and on January 25, 2017 it was measured at 361 AQI which is deemed extremely unhealthy.

Although particulate pollution levels are quite high in the capital, World Health Organization's numbers say it is 44th among the cities it monitors, in terms of fine particle (PM2.5) pollution. In terms of PM10, or coarse dust pollution, it ranks 71st. With unabated rise of personalised transport (rapid motorisation) and increasing congestion, the air pollution level is escalating to the previous terrible condition. According to the State of Global Air report, India and Bangladesh have experienced highest increases in air pollution levels since 2010.

One of the key solutions to solve Dhaka's traffic problem is to provide an adequate and effective public transport system. Dhaka is probably the only megacity where a proper public transport is virtually non-existent. Insufficient number of buses (and minibuses) along with mostly informal transports (para-transit) like rickshaws, CNG-fuelled three-wheelers, battery bikes, human haulers (locally known as Leguna, Maxi, etc.) cater to the demand of city-dwellers.

Scarcity of buses is not the only problem of the transport system. From the research studies done in Bengal Institute we have observed that there are mainly five main bus corridors in the city, and all of them run in the north-south direction. East-west connectivity is being provided by other informal transport or para-transit services, especially by human haulers. Even though the public transport services stop indiscriminately almost at every intersection, there is lack service in most of the areas in the city. The routes do not necessarily serve the traffic demand, rather they profit-driven. This results in utter chaos and unhealthy competition on the roads.

Experts and users both identified rain, bad roads and VIP movement as the main causes impeding smooth traffic flow. During the monsoon in 2017 the road condition became terrible, waterlogging was everywhere and spending more than two hours stuck in traffic daily has become the norm for Dhakaiites. The normal peak hour congestions in the morning and afternoon are compounded by frequent movement of VIPs and regular processions in the streets. Also, during Eid seasons the traffic situation in the highways was appalling; the commuters had to endure 10 or even 20km-long traffic jams.

Apart from traffic problems, the city is mainly facing two big problems, namely constant waterlogging (urban flooding) and migration (huge influx of people from other districts). We are yet to understand that climatic changes i.e. geologic changes and anthropogenic changes have a large impact on the capital city—along with some other factors, as research has indicated.

Climate change will physically affect Dhaka primarily in two ways: floods/drainage congestion and heat stress (a brief summary of few of the problems is described in the following sections). Long-term effects include in-migration (the term “climate refugees” has been floating around for a while), saltwater intrusion, loss of agricultural land, etc. Interestingly, Dhaka has never been the focal point in most discussions or studies on climate change. But the city had to take the brunt of many catastrophic disasters that have ravaged the country.

Existing transport routes and future proposals.

URBAN FLOODING AND WATERLOGGING

Waterlogging and drainage congestion due to river floods and excessive rainfall during the monsoon have already caused very serious damage. Flooding due to excessive rainfall is a severe problem in certain parts of the city, which get inundated for several days mainly due to poor and low capacity drainage system, clogged up sewer system, and inadequate pumping facilities to remove the stagnant water. In October 2017, newspaper reports noted that parts of the capital, including Malibagh, Rajarbagh, Mirpur, Mohammadpur, Shukrabad, Kalabagan and Bijoy Sarani, had been waterlogged. These areas, despite having an elevation of 60 feet and higher, were waterlogged due to excessive rainfall. The situation was so appalling that firemen had to ferry people on the submerged roads on their lifeboats at Shewrapara of Mirpur, Karwan Bazar and Motijheel areas during monsoon last year.

HEAT WAVES

Bangladesh ranked sixth among the world's top 10 countries most affected by extreme weather events in the last 20 years, according to Global Climate Risk Index published by the think-tank Germanwatch. The country's temperature during monsoon season is projected to increase by 0.7 degrees Celsius and by 1.3 degrees Celsius in the winter. Over the last 30 years, during March-November, Dhaka has been experiencing a slight increase in temperature and this average has sharply increased during the last five years, at a rate of 0.11 degrees Celsius. In recent days, the city has been going through extreme heat waves and humid weather in terms of frequency and intensity. Besides, Urban Heat Island (UHI) effect, i.e. specific characteristics of urban structures and anthropogenic heat sources, makes Dhaka city's temperature 1 to 5 degrees Celsius higher than the surrounding area.

EXCESSIVE AND ERRATIC RAINFALL

Climate change is increasing the temperature and therefore the potential for heavier rain. An estimation of yearly rainfall from 1978 to 2008 reflects an average rise of 4mm per annum in Dhaka. Observation suggests that since the number of days without rainfall is increasing, seasonal rainfall during monsoon (June-August) and winter (December-February) in Dhaka is decreasing during these periods, while sporadic heavy rainfall is becoming more frequent.

CLOUDBURST

On August 4, 2017, there was 123mm of rainfall in Dhaka in just three hours. This pattern of weather events has been observed in recent days. There had been no record of rainfall over 100mm in three hours since 2003.

SEASONAL AND RURAL-URBAN MIGRATION

Millions of people have already been displaced from the coastal areas of the country due to increasing salinity intrusion, erosion of river banks, cyclone and storm surges as well as lack of opportunities. Unsustainable levels of climate-induced displacement and migration are one of the apparent reasons for overpopulation, highly dense areas and congestion inside the city. Intergovernmental Panel on Climate Change (IPCC) estimates 20 million people will be displaced in Bangladesh in the coming five years.

Of all lifetime in-migrants, 42 percent went to Dhaka district and 56 percent to the three districts making up the Greater Dhaka Area (Dhaka, Gazipur and Narayanganj districts) (UNFPA, 2016). Three regions of Bangladesh are noted for their seasonal migration patterns: a) the Monga-prone districts in the northeast which suffer prolonged and severe drought during the winter, b) the southwest districts' people who suffer from sea level rise and saltwater intrusion in the dry season, and c) the northeastern haor-affected areas, which face flooding and waterlogging during the monsoon.

The topic of climate change has generally been overshadowed by other severe natural hazards. For instance, a year after the World Bank's study on climate change and sustainable development in Bangladesh, its country assistance strategy only mentioned climate change briefly, in the context of environmental problems. Nevertheless, BMZ, a German governmental organisation in a case study on climate change and conflict showed that this country has already been a primary victim of extreme weather events (cyclones, floods and droughts) that forced people to migrate. Finally in 2009, the ministry of environment and forests prepared and published Bangladesh Climate Change Strategy and Action Plan.

Almost half of Dhaka's population can be termed as urban poor not only in terms of their income level or living standard but also considering their accessibility to basic services and opportunity to resources. The city's existing problems will definitely be aggrieved by climate change, especially with the inflow of climate refugees. It is fast becoming one of the places for the marginalised who cannot afford to live anywhere else, but have to survive in the city for a living and have no other place to go.

Dhaka has started to move slowly but surely on the right track. It however is restricted by many problems, especially economic constraints and technical ability. It has developed a plan and various strategies with help from international agencies to mitigate or lessen the effects of climate change, and started taking very small steps to implement. Nonetheless, the planning and implementation of various projects and strategies tend to focus on the mid-term, if not the short-term. For instance, policies continue to be prepared in order to cope with natural disasters like floods, storm surges, cyclones, etc., rather than from the perspective of overall planning of mitigating the effects of climate change.

The same can be said about Dhaka's urban and transport planning. Many studies and plans under various projects since the 2000s have been done, namely Bangladesh Urban Air Quality Management Project (AQMP), Dhaka Urban Transport Development Study (DHUTS), Clean Air and Sustainable Environment (CASE) Preparation project, Strategic Transport Plan for Dhaka (STP), Detailed Area Plan (DAP), etc., by various authorities like Rajdhani Unnayan Kartripakkha (RAJUK), Planning Commission, Dhaka Transport Co-ordination Board (DTCB), Department of Environment (DoE) and many more. The two most recent additions to this list are Revised Strategic Transport Plan (RSTP) for Dhaka and Dhaka Structural Plan done by DTCB and RAJUK respectively.

But most of their recommendations or suggestions were not properly implemented or not implemented at all. Hopefully, the latest ones will not share the same fate as few of the public transport projects. We can look forward to sustainable planning and design for future Dhaka in 2018, which will take consideration of climate change impacts and transportation equity, and put emphasis on public transport and an inclusive approach.

Dhrubo Alam and Arfar Razi are research associates at the Bengal Institute.