Climate change is a systemic challenge. It interacts strongly with socio-economic factors and their regional and global trends.
Climate change is a systemic challenge that does not happen in isolation but interacts with socio-economic factors. Regional and global trends in these factors add an extra dynamic. They include geopolitics and conflicts; economic growth or decline; demographic change such as increase or decrease in populations, ageing, social segregation and migration; further urbanisation and urban sprawl; technological developments; a move to low-carbon energy systems; and many others. These can change the vulnerabilities of cities, for example by simply having a greater number of elderly people, who are generally more vulnerable to extreme events, or by placing people and assets in potentially risk-prone areas. On the positive side, some trends, such as better education or more trust in society, can offer the potential to increase the capacity to adapt. Climate change itself can trigger direct and indirect impacts that go beyond the sector or area originally affected. Interruptions in the supply chain and their impacts on production, jobs and income in other regions are one example of such knock-on effects. Adaptation solutions that focus on dealing with the direct impacts of climate change might therefore not be enough by themselves in the face of the much broader direct and indirect impacts of climate change.
Coping with extreme events and incrementally improving existing adaptation measures can offer effective short and medium-term solutions.
Coping and incremental adaptation are two approaches to dealing with climate change impacts. Coping mostly means responding to the damage arising from a disaster and recovery afterwards. Incremental adaptation builds on existing adaptation measures and known solutions by improving these, bit by bit, and increasing their capacity to avoid any damage under future levels of risk. Both approaches aim to maintain or regain the city's current level of service. Both are also based on proven knowledge gained over decades, for example in disaster risk management. Incremental adaptation often focuses on individual measures as appropriate and as opportunities appear. Measures are relatively quick to put in place. They can often deal sufficiently and very effectively with many short- and medium-term challenges.
Certain long-term effects of climate change, however, may be more than these approaches can cope with. Then, the measures can no longer protect against much larger impacts. For example, the city of Vác in Hungary successfully protected itself against flooding of the Danube with sandbags in 2002 and 2013, and has established a plan for using mobile dams. However, the second of those floods was higher than the first, and the question is whether or not the planned level of protection will be sufficient in the long term too.
Combining these solutions with transformative adaptation offers long-term solutions that address the systemic character of climate change and enable cities to embrace change.
Transformative adaptation, in our understanding (Table 3.1), follows a broader and systemic approach. It addresses the root causes. Vulnerability to climate change is often a result of human actions, such as settling in risk-prone areas, inadequate building design or other behaviours that aggravate the impact of climate change. In the example of Vác, providing more retention areas upstream to give room to the river may be part of a solution. This would, however, require a large-scale approach by cooperating with other cities, regions or even countries (Box 3.4).
The design of the city, its buildings and its infrastructures are supposed to last for decades or even centuries. Transformative adaptation can avoid letting these elements lock the city in to ways of functioning that will not work adequately in future climatic conditions and are hard to change. The transformative approach takes a systemic perspective.
It seeks to integrate adaptation with other aspects of urban development and turns the challenge into an opportunity, capitalising on many additional, non-climatic benefits. It departs from the state of the art of current city functioning and organises it differently, with the opportunity to function better and improve quality of life. For example, the amphibious houses in Maasbommel in the Netherlands are an attempt to live with different water levels instead of keeping the water out (see Box 5.26). Hamburg's green roof programme supports building owners to establish green roofs (Box 5.28). This measure will retain excess water and delay its entry into the sewerage system when rainfall is heavy. Extending the existing sewerage system as much as needed would cost a lot. It would still be uncertain how the system would work under long-term climate change and would also lock the city in to this way of dealing with excess water. The combination with green infrastructure solutions costs much less, is more flexible and is a low-regret measure: one with low costs and large benefits.