Natural Resources Defense Council (NRDC)
Climate change will impact water supplies, exacerbating existing pressures on water resources caused by population and economic growth. Given the combination of these stressors, the sustainability of water resources in future decades is a concern in many parts of the world. This study presents an integration of water withdrawal projections and future estimates of renewable water supply across the United States to assess future water availability in the face of a changing climate.
As part of this analysis, a water supply sustainability index composed of five attributes of water use and growth was developed, and used to compare impacts across regions.
We found that, under the business-as-usual scenario of demand growth, water supplies in 70% of counties in the US may be at risk to climate change, and approximately one-third of counties may be at high or extreme risk.
The geographic extent of potential risk to water supplies is greatly increased when climate change is considered (Figure ES-1). This calculation indicates the increase in risk that affected counties face that water demand will outstrip supplies, if no other remedial actions are taken. To be clear, it is not intended as a prediction that water shortages will occur, but rather where they are more likely to occur.
As a result, the pressure on public officials and water users to creatively manage demand and supply--through greater efficiency and realignment among competing uses, and by water recycling and creation of new supplies through treatment--will be greatest in these regions. In addition to developing national-scale maps of potential climate impacts, this work serves as a starting point for more detailed analysis, either at more local scales, or by consideration of specific sectors of the economy that are directly dependent on sustainable water resources.
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Tetra Tech, Inc.
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Reports & Presentations
Evaluating Sustainability of Projected Water Demands under Future Climate Change Scenarios, July 2010.
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Related Websit: NRDC
Carta da Terra
"Estamos diante de um momento crítico na história da Terra, numa época em que a humanidade deve escolher o seu futuro. À medida que o mundo torna-se cada vez mais interdependente e frágil, o futuro enfrenta, ao mesmo tempo, grandes perigos e grandes promessas. Para seguir adiante, devemos reconhecer que, no meio da uma magnífica diversidade de culturas e formas de vida, somos uma família humana e uma comunidade terrestre com um destino comum. Devemos somar forças para gerar uma sociedade sustentável global baseada no respeito pela natureza, nos direitos humanos universais, na justiça econômica e numa cultura da paz. Para chegar a este propósito, é imperativo que nós, os povos da Terra, declaremos nossa responsabilidade uns para com os outros, com a grande comunidade da vida, e com as futuras gerações." (da CARTA DA TERRA)