There is a finite quantity of fresh water on earth, and a quantifiable amount available for use by humans. Dr Anjani Ganase looks at the challenge of maintaining water supplies at satisfactory quality levels in all habitats.
Heavy rainfall over the last few weeks, and more recently last Friday in Tobago and Saturday in Trinidad, filled our rainwater tanks - all 1,800 gallons - in less than ten minutes, the same time it took to flood the rivers, cascade onto streets, and cause a three-hour traffic jam on major highways. The future projection for water distribution with the changing climate sees some places getting wetter (tropical zones), while other places will get drier (temperate zones). It also predicts more intense rainfall and periods of drought.
On a daily basis, we are flooded with reports of both wildfires and devastating floods. Areas that are wetter and more prone to flooding include the Amazon and the Orinoco basins. It is unclear where Trinidad and Tobago falls along the spectrum of shifting rainfall, we are expected to experience more intense bouts of rainfall along with hotter and drier dry seasons in the future. While global impacts are largely the results of climate change, the threat of water shortages and scarcity around the world is largely driven by our current unsustainable relationship with water. The world is nearing a water crisis that will only be exacerbated by climate change. Let's look at our current relationship with water and how we might circumvent the impending crisis.
All the water we need
Of all the water present on the planet, less than one per cent of the water is accessible via freshwater systems (aquifers, rivers, lakes etc). This small portion is what supports most terrestrial ecosystems, and all seven billion people living on the planet. Over the last century, we have improved water extraction processes by piping, damming and pumping water away from natural ecosystems. At the same time, we inject polluted water waste back to nature without understanding the consequences on the water cycle. We will not run out of water but are likely to run out of supplies of clean water. Groundwater supply accounts for most of the water around the world and many places are on overdraft.
Seventy per cent of the freshwater goes to agriculture: water not just for crops through irrigation, but also for the crops used in feeding livestock. The second largest consumers of water are production and processing industries (20 per cent). This leaves ten per cent of the water for domestic consumption. It is expected that domestic and industry water demands will increase rapidly by 2050 as the global population increases to over nine billion people. While agriculture will not increase as intensely, it will continue to be the largest component of water use. Geographically, the areas where water demands will increase the most include Africa and Asia as livelihoods improve. However, while parts of Africa have become wetter, large sections of Asia,
