Remote Sensing_**2010**, \(2\), 2305-2312; doi:10.3390/rs2092305  
_Remote Sensing_  
**ISSN 2072-4292**  
www.mdpi.com/journal/remotesensing  
Global Croplands and their Importance for Water and Food Security in the Twenty-first Century: Towards an Ever Green Revolution that Combines a Second Green Revolution with a Blue Revolution  
**[PERSON]**  
Southwest Geographic Science Center, U.S. Geological Survey, Flagstaff, AZ, USA;  
E-Mail: [EMAIL_ADDRESS] or [EMAIL_ADDRESS]  
_Received: 6 September 2010; in revised form: 17 September 2010 / Published: 27 September 2010_  
In an increasingly food insecure world, there is a critical need for us to have a comprehensive understanding of global croplands. The reality that the \"green revolution\" has ended is beginning to be felt around the World. Whereas, global population continues to increase at a rate of about 100 million per year and is expected to reach around 10 billion by 2050, cropland areas are not increasing and have stagnated around 1.5 billion hectares globally. Indeed, cropland areas have even begun to decrease in some countries with important food contribution (e.g., USA) due to increasing demand of fertile arable lands for alternative uses such as bio-fuels, encroachment from urbanization, and industrialization. The ecological and environmental imperatives have put a cap on further increase of cropland areas to other lands such as forests and rangelands. These issues leave us with a fundamental and urgent question to answer: \"_how does the world ensure food security for its ballooning population without having to increase cropland areas and or water allocations_?\". _Indeed, even better question to ask is_: \"_how does the world ensure food security for its ballooning population even by reducing the existing cropland areas and or water allocations_?\". Solutions such as from bio-technology and precision farming may come through but it is not currently moving at a rate that will ensure global food security over next few decades. Further, there is a need for careful consideration of possible harmful effects of bio-technology. We should not be looking back 30-50 years from now, like we have been looking back now at many mistakes made during the green revolution where the focus was only on getting more yield per unit area without much thought about serious damage done to our natural environments, water resources, and human health as a result of detrimental factors such as uncontrolled use of herbicides-pesticides-nutrients, drastic groundwater mining, and salinization of fertile soils due to over irrigation. Currently, there is a talk about a \"second green revolution\" or even an \"ever green revolution\", but clear ideas on what actually these terms mean are still debated and are evolving. The first green revolution (increase in productivity per unit of land) came through a series of factors: high-yielding varieties, fast growing varieties, irrigation, supplemental irrigation, crop intensification, and farm management (e.g., application of nutrients, herbicides, pesticides, and drainage) (see Figure 1). But after nearly half a century of green revolution era (roughly, 1955-2005), the World finds itself with number of problems associated with it, such as: salinization, deep mining for ground water resulting in its fast depletion to levels that are no more sustainable, surface and ground water pollution due to over application of herbicides-pesticides-nutrients, and over use of water for irrigation. It is clear that unless these issues are addressed adequately and new technologies like bio-technology is sufficiently clean, the required parameters for moving towards a \"second green revolution\" or \"ever green revolution\" will be hard to visualize, let alone implement. One of the biggest issues that is not given adequate focus is the use of large quantities of water for food production. Indeed, an overwhelming proportion (about 80%) of all human water use goes for producing our food.