The population of the United States will pass 300 million today, or tomorrow. No one knows exactly where, no one know precisely when. It is a milestone for sure but is this a cause for celebration or anxiety?
Some American commentators are already saying the landmark is a chance to note the US is perhaps the only country in the developed world where the economy is being bolstered by a population that is growing at a discernable rate. But many experts say passing the 300 million milestone should be a wake-up call that demands a reappraisal of the extraordinary, unparalleled rate of consumption by the world's largest economy and its third largest by population.
As an economic model for the rest of the world to follow - in particular the rapidly developing economies of China and India - it is unsustainable, they say.
On a global scale the average US citizen uses far more than his or her fair share of the planet's resources - consuming more than four times the worldwide average of energy, almost three times as much water and producing more than twice the average amount of rubbish and five times the amount of carbon dioxide, a major contributor to global warming.
It may be that America's citizen number 300,000,000 will be an undocumented migrant, born to undocumented parents somewhere in the South or the West, where population growth is the fastest.
Almost one-third of America's annual population growth of between 0.9 per cent and 1 per cent is the result of immigration - much of it illegal.
"America is the only industrialized nation in the world experiencing significant population growth," Victoria Markham, the director of the Centre for Environment and Population (CEP), says in a new report.
"The nation's relatively high rates of population growth, natural resource consumption and pollution combine to create the largest environmental impact, felt both within the nation and around the world."
'More of more' seems to characterize modern-day America - more people than any generation before us experienced, more natural resources being utilized to support everyday life and more major impacts on the natural systems that support life on earth."
Lester Brown, the director of the Earth Policy Institute, an environmental group also based in Washington, said: "In times past, reaching such a demographic milestone might have been a cause for celebration - in 2006 it is not.
It contributes to water shortages, cropland conversion to non-farm uses, traffic congestion, more garbage, overfishing, crowding in national parks, a growing dependence on imported oil and other conditions that diminish the quality of our daily lives."
If China's economy continued to grow at 8 per cent a year, Mr Brown said, income levels in that country would equal the 2004 US level by 2031, by which time China's population would stand at 1.45 billion.
Supersize nation: How America is eating the world
300m Expected population of the United States by the end of this week
75 Life expectancy for men in the US. Women are expected to live until 80
63 Life expectancy for men in the developing world. Women are expected to live until 67
395m Projected population of the US by 2050
1,682m3 US annual water consumption per capita
633m3 The world's annual water consumption per capita
545m3 The developing world's annual water withdrawals per capita
5lbs Amount of waste each US resident produces per day. That compares with about 3lbs per person per day in Europe, and about 0.9-1.3lbs per person a day in the developing world
$39,710 US Gross National Income per head, 2004
$8,540 World's GNI per head
$4,450 Developing world's GNI per head
19.8 US carbon dioxide emissions per capita, in metric tons
3.9 World's carbon dioxide emissions per head, in tons
1.8 Developing world's carbon dioxide emissions per head, in tons
58bn Number of burgers consumed by Americans every year
54m Number of Americans who are obese
300,000 Deaths per year related to obesity
678lbs US annual paper consumption per head
115lbs The corresponding figure for the world
44lbs The figure for the developing world
204m number of vehicles on US roads
37% Percentage of the total cars in the world on America's roads
1 in 7 Barrels of world oil supply used by US drivers
24m Number of Americans who drive SUVs
7,921 US energy consumption per capita, 2001, expressed in kilograms of oil
1,631 World's energy consumption per capita, in kilograms of oil
828 Corresponding figure for the developing world