Water, the other item on the climate agenda

Water is one of the first victims of climate change. Climate change alters rainfall distribution both in terms of where it rains and when, resulting, in many regions in water scarcity becoming more widespread, or conversely, in a succession of floods, to the point where water, which was regarded as an issue of real progress, has once again become a priority for many countries. One of the challenges for the COP 22, which is currently taking place in Marrakech, is to put water back in its rightful place among the strategies used to mitigate climate change and to adapt to it.


Striking the right balance between adaptation and mitigation

First mitigation, because water, and more specifically wastewater, can become a source of renewable energy and thus reduce greenhouse gas emissions. Apart from the well-known case of hydroelectricity, the calories from wastewater can be recovered to heat buildings. Another example is that of wastewater treatment plants, which in the future will produce energy instead of consuming it. 

And then adaptation. In Copenhagen, to reduce the vulnerability of certain districts to flooding, we have made the rainwater network “smart”, linked it to a weather warning system and prepared scenarios to anticipate and manage crises. In Durban, a city weakened by a major water deficit, we recycle industrial wastewater, which preserves fresh water resources to be used by the population: when there are shortages, water is too precious a resource to be used only once before being returned to nature.

Milwaukee - USA

Alternative resources are one of the main weapons that can be used to deal with global warming and the risks of drought that go with it. Many cities have increased the number of seawater desalination and wastewater recycling plants in order to free their water supply systems from insufficient rainfall. Security through diversity, is how their adaptation policy can be characterized. It is an effective policy, but one that must be combined with a policy to mitigate climate change. Because the more man mitigates climate change, the easier it will be to adapt to it.


Quality without compromise


Pollution has repercussions on the availability of quality freshwater, and makes it more scarce. It also has consequences for hygiene, public health, food safety and ecosystems. For that reason, one cannot separate the quantitative from the qualitative, or the fight against scarcity from the fight against pollution. However, much is yet to be done in the fight against pollution: 40% of Mediterranean towns with more than 2,000 inhabitants do not have a wastewater treatment plant; worldwide, 2.4 billion people do not have access to basic sanitation. Taking out less and cleaning up more, saving more and stopping pollution, this is the direction in which we should be going if we want to be water’s friend… and the climate’s one.

Climate change, hydrographic imbalances. Water is one of the sectors most affected by changes in the climate. Of course, we cannot control the climate, but we can save water, we can recycle it, and we can extract renewable energy from it. In the titanic battle that is underway against climate change, we haven’t heard the last from mankind!