... if you look at the way cities behave, they are parasitic on landscape. In every aspect of whatever they need, they get it from some other place .… - Dickson Despommier

Time Line for 1937 – Discovered in Uganda in the . Mistaken at first for 1951 – Israeli scientists determine the conditions for transmission from the perspective of mosquitoes. Temperature vrs. 1973 – Biggest outbreak in history in South Africa – 3,000 people sick. Hot and dry conditions followed by heavy rains
1999 – West Nile Virus first introduced in USA. Hottest, driest summer on record.
2010 – West Nile virus now an endemic infectious disease of and people. Yearly outbreaks common. All dependent on hot, dry weather, followed by a rain event

mainly differ amongst each other in terms of the technological methods used to grow edible plants indoors.
1. The first one, , consists of growing plants on a neutral and inert substrate (e.g. sand, clay, and rock material), which is regularly irrigated by a liquid fortified with minerals and nutrients that are necessary to sustain plant growth. Hydroponic systems use 60-70% less water than traditional outdoor agriculture. They are widely employed by hundreds of thousands of commercial greenhouses and vertical farms throughout the world.
2. The second process of vertical farming is , through which plants are grown without the use of any soil (or soil replacement): their roots, hanging down in the air inside a closed container, are exposed to a fine mist of nutrient-laden water, regularly sprayed through a nozzle. While this is a relatively new method for growing edible plants – it was first developed in 1983 – it is increasingly employed by commercial vertical farms such as and Tower Garden in the US. 3. Finally, a hybrid method, , integrates fish production into the hydroponic growing scheme. More precisely, it uses fish waste as a nutrient source for the plants after treatment, operating as a closed loop ecosystem for indoor farming. However, this system’s complexity and high cost hinder its widespread use. The former two methods are the most common forms of .

... People tire of being taken advantage of. Some commit their lives to reforming city politics, and others work on technological solutions that benefit both humankind and . The latter efforts have led to (1) the development of efficient, affordable renewable-energy strategies; (2) carbon-capturing, recyclable construction materials with low s; (3) cost-effective atmospheric water-harvesting methods; and (4) productive vertical farms situated within the city. issues are now front and center on many city council agendas. I call these four applications of technology the four pillars of sustainability.