Connecting dots between energy, water, food, ecosystems and climate change
Climate change creates critical challenges to meet future energy and water needs because they are interconnected. Energy is used to extract, convey, treat, distribute, and heat water. This energy used in water is known as the water’s energy intensity, total amount of energy required for the use of a given amount of water in a specific location. However, only recently the Climate Change Program at California Department of Water Resources has first efforts begun to bridge energy intensity data gaps for the state water supplies, which are critical for public decision making about sustainable choices for agricultural food production and urban consumption. A regional approach was used to estimate energy intensity required for the extraction and conveyance of water from ten hydrological regions in California. Regional energy intensity indices were indicated by different sizes and numbers of light bulbs for ground water, and federal, state and local water supplies in the web-based California Water Plan Update.
The complex connections of water and energy were explained by a visual diagram, including connections where water is used in the generation of hydropower, solar, biofuels and other energy, and where energy is used in the water cycle for urban and agriculture users. The study showed there was a large variation in average energy intensity values estimated from ground water and federal, state and local water supplies both within each hydrological region and among ten hydrological regions in California. For example, the South Coast region had relative high energy intensity from State Water Project supply compared to other regions; the energy intensity from local water projects was relatively low compared to other water supplies in this region. The results indicated regional decisions were critical to address water-energy conflicts and meet local challenges of climate change impacts including drought. Additionally ecosystem service benefits were explored, including saving water and energy, reduced carbon footprint, and better water quality and habitat values. This water-energy framework provides a useful tool for regional water and energy efficiency programs with cost effective investments. It can inform public decision making on water, energy and food choice issues in order to most efficiently use limited natural resources and best meet future demand. Also it could help addressing water-energy conflicts under the similar climate change effects like the American West and other world.