Since early 2007, global food prices have increased by 30%, placing the issue of food price inflation as a top priority for policymakers at the local, national, and international level. The price of cereals such as wheat, rice and corn has risen by 50%, while the cost of dairy products, oils, and fats has increased by an even higher percentage (see Figure 1 below).

While rising food prices can have economic impacts across all segments of the population, the results are felt most acutely by the global poor. Nearly three billion people earn less than $2.00 a day and spend, on average, well over one-half of their household income on food. The urban poor, who typically do not produce their own food, are particularly vulnerable to price fluctuations.

The process of nutrient cycling is critical to all ecosystem services. However, when the flux of nutrients into the environment exceeds the ability of natural systems to absorb them, aquatic ecosystems feel the greatest impact. An oversupply of nutrients in aquatic systems can cause excessive growth of algae, reduce species diversity, damage coral reefs, and, in extreme cases, create oxygen-depleted "dead zones."

The United Nations' Millennium Assessment estimates that the current rate of species extinction is 1,000 times greater than it would be without human-induced habitat change, introduction of invasive species, and overexploitation. Last month, the World Conservation Union's (IUCN's) 2007 Red List, an annual report on the conservation status of the world's species, provided a more thorough accounting of this biodiversity loss. The IUCN reports that one in four mammals, one in eight birds, and one in three amphibians are in jeopardy (see table below).

In both the United States and Western Europe, the effects of pollution on human health have declined dramatically in the last half-century. Widespread industrial pollution persists, however, in many regions of the world. More than a million people still die each year from urban air pollution and lead poisoning, and over 80 percent of all diseases recorded by the World Health Organization are wholly or partially attributable to environmental factors (WHO 2006).

Earlier this month, the Blacksmith Institute's Polluted Places Initiative released an unranked list of the 10 most polluted cities in the world. More than 400 cities were nominated and evaluated for this dubious honor. The winners are not ranked, but are presented below, alphabetically by country.

On Saturday, the governing body for the United Nations Convention to Combat Desertification (UNCCD) concluded its 8th Conference of Parties (COP) meeting in Madrid. While organizers were happy to report the passage of a new 10-year plan of action and the appointment of a new Secretary-General, the conference's failure to approve a final budget inspired criticism from some environmental groups.

About once a month, one of our users sends an e-mail to EarthTrends with a variation of the above, usually with an emphasis on resource consumption in the United States. Resource consumption can be tricky to measure. Is monetary expenditure a good proxy for consumption? What about the quantity of objects consumed? How do we account for recycling, or expenditures in the service sector? We'll consider a few different angles on the consumption question below.

In monetary terms, most consumption still occurs in industrialized nations; according to the World Bank, the 2.3 billion residents of low-income countries accounted for less than 3% of public and private consumption in 2004, while the 1 billion residents of high-income countries consumed more than 80% of the global total (See Figure 1.) In this same year the United States accounted for 4.6 percent of the world's population and 33 percent of global consumption--more than $9 trillion U.S. dollars.

Sustainable development requires simultaneous attention to economic growth, environmental protection, and social equity in order to meet the needs of present generations without compromising those of the future. Secure tenure over land and resources by all segments of society, and particularly by the poor, has been identified as a critical enabling condition for this to occur. Specifically, tenure is thought to be essential to the eradication of extreme poverty, improved environmental stewardship, and reduced resource consumption (Deininger et al. 2003).

Which country in each of the following pairs has the higher infant mortality:

        Sri Lanka or Turkey?
        Poland or South Korea?
        Russia or Malaysia?
        Pakistan or Viet Nam?
        South Africa or Thailand?

When Hans Rosling asked his Swedish health policy students these same questions, they averaged 1.8 correct responses out of 5 (a chimpanzee would average 2.5; score yourself using the following answers obtained from EarthTrends).

On EarthTrends, our mission is to collect international data sets that track global, regional, and national changes over time that relate to the environment and human well-being. One of our greatest challenges has been to collect internationally comparable freshwater statistics; water data sets are typically sparse syntheses from national or regional studies with varying collection and calculation methodologies. (See Ask EarthTrends: Where can I find water use, water pollution, and/or water resources data? for more information on this topic.)

As a result, we are excited to see how NASA's Gravity Recovery and Climate Experiment (GRACE) satellite data have predicted river flows and freshwater storage continuously since 2002, with important applications for both climate and water management policy.

Sometime this month--officially Tuesday of this week (although no one knows for sure)--the population of the United States reached 300 million.

Only two countries--China and India--have arrived at this total faster, and the U.S. continues to grow at a rate that exceeds any of its industrialized peers. Although the 300 million milestone is really no less arbitrary than 290 or 310 million, it should give pause to anyone who has ever sat in bumper-to-bumper traffic.

With the U.S. population expected to reach 400 million within the next forty years or so, one may wonder: how will the U.S. and the world respond to the rapid addition of "average Americans" and their current cumulative consumption patterns?