Today 70% of people in the world can count on having running water in their homes. They turn on a tap and clean water runs out as much as they want, whenever they want and they forget that the quest for drinking water has been one of the most essential struggles of their ancestors. In fact, by 2040 most of the earth will not have sufficient water to fulfill year-round demand.
Earth is covered with more than 300 million trillion gallons of water and that is why it is called the blue planet.
Water may freeze into ice or evaporate into air but does not leave the planet. But the problem is 97% the planet water is salty and 2% is trapped in ice so the life of all of us depends on on just 1% of that water to survive. The access to this small portion is also very dependent on where you live. Most of this 1% water that we rely on is underground which makes it challenging and costly to access it. That’s why more than 90% of earth population lives less than ten kilometers from fresh water e.g. lakes and rivers. Thanks to the enhancements in drilling and excavating technologies, our access to ground water has improved a lot. However, there is a catch, those water deposits known as aquifers have accumulated over thousands years and will take the same time to replenish.
NASA satellite data reveals that in just ten years aquifers in northern India have been reduced by 29 trillion gallons.
On the other hand, climate change has worsened the water scarcity as when greenhouse gases accumulate and the atmosphere warms, the water cycle changes. Global warming accelerates melting of sea ice and glaciers, which returns back the water that has been stored for hundreds of centuries into the dynamic water cycle. Higher temperature results in higher evaporation of that newly introduced water and additional water vapor in the atmosphere. Since water vapor is a potent greenhouse gas, higher evaporation leads to higher temperature and the cycle goes on. This phenomenon known as a positive feedback loop. Consequently, increase in evaporation, intensifies water scarcity too.
Another important factor in water scarcity is unsustainable growth in agriculture and industry as well as changing eating diet. Basic human need for water including drinking, washing, etc., only accounts for 8% of our annual freshwater usage while the rest goes to agriculture and industry.
For instance, 98% of the water in a bottle of Coke is not what you see in the bottle and it is embedded in all the ingredients that were grown to make that bottle of Coke.
Figure below shows the water footprint for a few products that we commonly eat or drink. As you can see in the picture, 2400 litter of water is used for producing a hamburger. Unfortunately, the way the world eats has changed a lot and people are more into the American style of eating, higher calorie diets with more meat. However, there is not enough water and land in the world for everyone to eat like Americans.
Water does not conform to some of the basic rules of capitalism. Farmers pay almost nothing for it, so the real cost of water does not count in the burger cost. This explains why fast food restaurants can offer burgers at very cheap price.
Now from big picture to specific application, in our mission to reduce UHN’s GHG emissions and make it a more sustainable place for patients and staff, we recently upgraded the refrigeration system of the nutrition department at Lyndhurst. The old, inefficient and city water-cooled refrigeration system that was serving three walk-in coolers and one freezer replaced with an efficient and reliable air-cooled system. You may be shocked when you notice that the old systems were using potable water for emitting heat from the refrigeration system and then the water drained into the sewer. That was a common practice 30 years ago when water was less scarce.
This water saving opportunity was identified during a water audit sponsored by the City of Toronto and as a result of changing water-cooled to air-cooled, we save about 1,500m3 of drinking water every year. Cheers to that.