Climate Change and Water

It has been said that “if climate change is a shark, then water is its teeth.” In other words, how most of us will feel the impacts of a changing climate will occur through our relationship with water. Due to the warming of the atmosphere caused by manmade greenhouse gas (GHG) emissions since the industrial revolution, more water vapor is now held. According to NASA, that water vapor then amplifies the effects of climate change leading to more frequent and intense, water-related events such as floods, droughts and extreme storms.

Perhaps the most immediate threat to water availability from climate change is the impact of drought, both in areas historically prone to it and in new locations where extreme weather events are suddenly occurring with more frequency. According to the UN, approximately 2 billion people today do not have safe access to drinking water and by 2030 global freshwater demand will exceed supply by 40% (according to the World Economic Forum). Complicating the picture further is that studies estimate that nearly 80% of wastewater is returned to the environment untreated.

While we briefly touched on the energy-water nexus in the previous lesson, let’s now build on that initial understanding. When it comes to our drinking water, the monthly bill we pay is almost entirely a reflection of the amount of embedded energy per gallon of water. Extracting water from surface or groundwater supplies requires energy (pumps, wells, distribution system); cleaning water to potable standards requires energy (turbines for removing impurities, reverse osmosis); and then finally distributing clean drinking water to residents requires energy (pumping water through a municipal system).

On the wastewater side of the equation, significant energy resources are needed to clean wastewater before it is released into the environment; and wastewater utilities emit significant amounts of methane from anaerobic digesters that help breakdown organic matter in waste. In fact, the World Economic Forum estimates that water and wastewater utilities account for 5% of GHG emissions globally; but additional research estimates that could increase to 10% as the global gap on providing sanitation services narrows (World Economic Forum: How tackling wastewater can help corporations achieve climate goals).

Thus, in order to meet the drinking water and wastewater demands of a growing population globally where freshwater resources are under greater stress (UN SDG 6), more water utilities will need to be built, requiring more energy resources and resulting in GHG emissions that could possibly work at odds with global efforts to reduce such emissions (UN SDG 7). From the water footprint exercise in Lesson 12, we learned first-hand how our lifestyle choices can impact our water footprint. As the availability of freshwater supplies is stressed, and in some cases locally threatened, this will place pressure in those regions or sectors that rely on water resources like the energy sector and the food and beverage sector.

Reference:

World Economic Forum. How tackling wastewater can help corporations achieve climate goals. Retrieved Dec. 8, 2023 from https://www.weforum.org/agenda/2022/10/wastewater-corporations-climate-g.....