The speech I went to was about how we as a global community are overusing water. Most of the available water is being used for crops. The speaker was Fred Pearce who authored the book "When the Rivers Run Dry" which is about the global water crisis. One of his main points was that in order to keep supplying the world with food we must change our habits.
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The biggest thing is going to be catching more of the available water. The easiest way to do this is to catch the rain water that falls on the roofs of houses. Also we must accept that people are going to have to start drinking sewage water that has been cleaned. The world is set up to allow for about 1,500 gallons per year through food, clothing, and personal consumption. Based on what he uses the average person in the US used 2,000. 500 more gallons than that is available. At the current rate by 2025 grain production will go down by one loaf of bread per week for every person on the planet, in the US this will not be a big deal but for people in other parts of the world this may be the only grains they get.
He said we need to have a blue revolution. Much like the green revolution that yielded more crops on the same amount of land we need to find a way to grow the same amount of crops with less water. Although the high yield crops feed the world they use more water than the supposed inefficient crops they replaced. So in order to keep feeding the world we must create more water efficient crops. One way he suggested was drip irrigation instead of the popular flooding irrigation used in many parts of the world. It is a big problem but unaddressed it could lead to harmful consequences as unlike the oil crisis we can not survive without water.
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