Much of this urbanisation will unfold in Africa and Asia, bringing huge social, economic and environmental transformations.
Urbanisation has the potential to usher in a new era of well-being, resource efficiency and economic growth.
But cities are also home to high concentrations of poverty. Nowhere is the rise of inequality clearer than in urban areas, where wealthy communities coexist alongside and separate from, slums and informal settlements.
Rapid urbanisation under poverty
“Around 40 percent of the African population currently lives in the urban areas; By 2050 this number is going to increase to 61.8 percent of Africa’s projected, Institute of Human Settlements Studies Ardhi University, Prof Alphonce Kyessi said during the Climate Change Impact, Adaptation and Mitigation (CCIAM) workshop in Dar es Salaam recently.
The aim of the workshop was to present research findings concerning impacts of climate change on human settlements.
He said that informal urbanisation– growth and expansion of the informal sector, including informal settlements, leading to economic inefficiency, environmental degradation and human misery.
Dominating informal settlements
He said a large percentage (about 80 percent) of the residential houses in the Tanzanian urban context can be classified as informal settlements (more than 100 in Dar es Salaam occupying above 5,197 hectares);
Kyessi added that the informal settlements can be characterised by their generally low quality of construction and poor living condition –liable to flooding noting that the most recurrent construction types in the informal settlements can be classified as adobe, rammed earth, mud and wood and cement –stabilized brick.
Challenge to human settlements
“Many settlements concentrate on the coastline, along rivers and steep slopes facing many climate change challenges of sea level rise, induced flood hazards and landslides” he said.
He explained that they are particularly vulnerable to the effects of climate change because of multiple stresses and low adaptive capacities, arising from endemic poverty, weak institutions, and complex disasters and associated conflicts.
“Human activities, in particular fossil fuel use and changing land-uses are the dominant factor in the growth of atmospheric greenhouse gases and are responsible for most of the warming observed over the past 50 years.
“Impacts on the environment and society are inevitable,” he explained in detail.
Trends in climate-related disasters
He detailed that the storm frequency and temperature have increased since the 1970s, the Sahel and Southern Africa have become drier during the twentieth century.
However he said that water supplies and agricultural production will become even more severely diminished. By 2020, in some African countries agricultural yields could be reduced by as much as 50 percent.
By the 2080s, the area of arid and semiarid land in Africa will likely increase by 5-8 percent.
On the other hand he said weather-related disasters are doing increasing damage to water and food supply which are already scarce in many places.
Critical infrastructure such as energy, roads and drainage, transport, telecommunication towers and sanitation are becoming more vulnerable to climate change related risks, he said.
Insufficient levels of urban planning and government investments in infrastructure – in many settlements, especially urban areas, infrastructure development and economic growth lag behind the rapidly-growing urbanization phenomenon.
Extent of impacts
A 2011 Study projected exposure of Dar es Salaam city’s Population (more than 100,000 residents) to a 100 year storm event by 2030 if no adaptation measures are taken. By the year 2050, coastal and inland assets worth US$2,000 million will be exposed to CC impacts.
Temeke’s coastal areas have most people at risk when compared to Ilala.
The December 2011 flooding displaced about 10,000 people and affected 50,000 people in Dar es Salaam while the April 2014 floods displaced about 2,000 people, entering 600 houses, washing away 13 houses and requiring 283 patients to be treated for waterborne diseases.
Managing the Impacts
He said that one of the ways to manage the impact is developing a comprehensive vision of the settlement green structure through green infrastructure planning, compact and green settlement development is a prerequisite for the protection and development of the green infrastructure.
Also densification should include planning of green areas to achieve an adequate level of supply of green areas within the built matrix for example in urban areas, river corridors should be protected and rehabilitated where necessary as the multifunctional green backbones of the settlement for example a city.
“Urban agriculture and urban forestry are suggested as key strategies for sustainable development and adaptation of Tanzanian urban centres to climate change,” Professor Kyessi said.