2008 IUCN Red List warns that long-term droughts and extreme weather puts additional stress on key habitats and, for example, lists 1,226 bird species as threatened with extinction, which is one-in-eight of all bird species. Backstop water sources The concept of a "backstop" resource is a resource that is sufficiently abundant and sustainable to replace non-renewable resources. Thus, solar and other renewable energy sources are considered "backstop" energy options for unsustainable fossil fuels. Similarly, Gleick and Palaniappan defined "backstop water sources" to be those resources that can replace unsustainable and non-renewable use of water, albeit typically at a higher cost. The classic backstop water source is desalination of seawater. If the rate of water production is not sufficient in one area, another "backstop" could be increased interbasin transfers, such as pipelines to carry freshwater from where it is abundant to an area where water is needed. Water can be imported into an area using water trucks. The most expensive and last resort measures of getting water to a community such as desalination, water transfers are called "backstop" water sources. Fog catchers are the most extreme of backstop methods. To produce that fresh water, it can be obtained from ocean water through desalination. A 17 January 2008 article in the Wall Street Journal stated, "World-wide, 13,080 desalination plants produce more than of water a day, according to the International Desalination Association". In 2005 Israel was desalinizing water at a cost of US$0.53 per cubic meter. In 2006 Singapore was desalinizing water for US$0.49 per cubic meter. In 2008 after being desalinized at Jubail, Saudi Arabia, water was pumped inland though a pipeline to the capital city of Riyadh. However, several factors prevent desalination from being a panacea for water shortages: Energy required to desalinate the water Environmental issues with the disposal of the resulting brine High capital costs to build the desalination plant High cost of the water produced High cost of transporting water Nevertheless, some countries like Spain increasingly rely on desalination because costs of the technology continue to drop. At last resort, it is possible in some particular regions to harvest water from fog using nets. The water from the nets drips into a tube. The tubes from several nets lead to a holding tank. Using this method, small communities on the edge of deserts can get water for drinking, gardening, showering and clothes washing. Critics say that fog