With President Obama barely back from the climate change conference in Copenhagen, his anti-global warming accord is evidently already working its wonders, unleashing a blizzard to blanket the East Coast with snow.

With climate in the news, it's a good time to review the Census Bureau study of the factor that will have the single greatest impact on U.S. carbon emissions over the next 40 years: immigration.

With a couple of weeks left in the decade, the Census Bureau has finally gotten around to releasing What If? projections showing the impact of various immigration policies on America's population (which is today 308 million):

"… a greater number of migrants arriving in the United States will correspond to a larger increase in the size of the total population. Under the assumption of a high level of net international migration, the population is expected to grow to 458 million by 2050. … "
[United States Population Projections: 2000 to 2050 by Jennifer M. Ortman and Christine E. Guarneri of the Census Bureau]

That's an increase of 150 million carbon-belching residents of America.

"In contrast, for the Zero Net International Migration series the population will increase slightly by 2050 to 323 million. "

That's an increase of only 15 million.

In other words, immigration policy will determine whether the population grows over the next four decades by 150 million or by 15 million—an order of magnitude!

Although the new Census Bureau projections were released last week at the peak of the media frenzy over Copenhagen, not a single one of the 387 articles tabulated by Google News mentioned "carbon," "climate," or "warming."

Americans are just not supposed to think about the link between immigration, population, and carbon emissions. Ignorance is Strength!

Mark Twain famously said: "Everybody talks about the weather but nobody does anything about it." Yet the conventional wisdom in this decade has been that we should be passionately doing something—anything—about the weather, but not even talking about the population.

The Census Bureau's 2009 projections are based on their 2008 projection, which I discussed in VDARE.com last year. The old forecast just assumed a single best-guess that the net number of immigrants would grow to over 2.0 million per year by 2050.

This year's projections—which got a little publicity because they pushed back slightly the date at which whites are set to become a minority in America—feature four different scenarios regarding net immigration (see Figure 1 in the report). This allows us a much better understanding of effect of immigration:

• High Immigration: Net immigration grows to an annual rate of 2.4 million by 2050, and the total population reaches 458 million (of which 144 million would be Hispanic).

• "Low" Immigration: Net immigration reaches 1.7 million by the middle of the century, and the population climbs to 423 million (124 million Hispanics).

• Constant Immigration: The net number of immigrants stays flat at just under one million per year, and the population hits 399 million (111 million Hispanics).

• Zero Immigration: The number of immigrants equals the number of emigrants, and the population peaks at 323 million in 2050 (68 million Hispanics).

Please note something that the Census Bureau doesn't quite make clear: "Zero Net International Migration" doesn't mean zero immigration. It means that the number of emigrants and immigrants must be equal. Since a few hundred thousand people emigrate from the U.S. each year, a few hundred thousand immigrants per year could be accommodated under a policy of Zero Net International Migration.

You'll notice that the Census Bureau's "Low" immigration scenario is higher than the Constant scenario of under a million net immigrants per year. "Low" assumes almost a doubling of the annual number of immigrants over the next 40 years.

In other words, the Census Bureau is assuming, rightly, that without a major political effort to limit immigration, the annual number of immigrants will inevitably expand.

That's because immigration naturally tends to feed upon itself. Moving to America becomes easier the more friends and relatives a potential immigrant already has in America.

In contrast, there are 240 million people in Indonesia, but the 2000 Census found only 63,000 Indonesians in this country. With so few friends and relatives currently established in the U.S., moving to America affords Indonesians a daunting prospect. Yet, if we allow the Indonesian beachheads in America to expand, eventually they will be large enough to attract an exponentially growing number of Indonesians. (And there are a lot of Indonesians…)

It's instructive to extend out the scenarios from the Census Bureau's stopping point in the year 2050 to 2100.

Under the High Immigration assumptions, the Census Bureau expects the annual increase in population to slowly decline from 1.06 percent in 2010 to 0.89 percent in 2050. If we assume the same rate of deceleration of growth in the second half of the century, down to a 0.64 percent annual increase by 2100, America's population will then be 668 million.

That's 668,000,000.

It would be intriguing to ask the Climate Change folks what they think about America's population swelling to 668 million. But, of course, they wouldn't answer. They'd just sputter and call you names.

Besides immigration rates, another key number in projecting populations is the Total Fertility Rate (the number of babies per woman per lifetime). The Census Bureau appears to be lowballing its forecasts by underestimating the Hispanic TFR. The Census number crunchers assume that the Latino Total Fertility Rate was 2.73 in 2001 and that it falls gently to 2.70 in 2010 and down to 2.29 in 2050.

In reality, the Hispanic Total Fertility Rate rose significantly in this decade, reaching 2.99 in 2007, the last year for which we have annual data. (I wouldn't be surprised, however, if the Hispanic birth rate drops by 2009, due to high unemployment among Hispanics, especially construction workers following the bursting of the delusionary Housing Bubble.)

It's crucial to understand the long run impact of high fertility rates among immigrants. When a country admits an immigrant, it is also admitting descendents unto the seventh generation.

Different cultures bring radically different fertility patterns to the U.S. We can't afford to be oblivious to the implications any longer.

For example, in 2005, the TFR in California of foreign-born Latinas was 3.7, while it was 2.2 among American-born Latinas. This means that the typical Latina immigrant can expect to have over 8.1 grandchildren, or double the replacement rate. In contrast, Asian immigrant women in California can expect 2.8 grandchildren (2.0 TFR for the first generation and 1.4 in subsequent generations). American-born white women in California can expect to average 2.6 grandchildren each due to their 1.6 TFR.

Hence letting in a Hispanic immigrant leads to almost three times as many babies being born two generations from now as letting in an Asian immigrant, or an American woman moving to California from another state.

The long run political implications for the Republican Party of massive Hispanic immigration were spelled out by Antonio Gonzalez, head of a Latino voter registration group:

"If there is one group you could say that does not share the Republican small-government philosophy, it's Latinos. … We are Big-Government, government-safety-net, activist-government [voters]. There is a feeling in the community that today we hurt, but tomorrow is ours, so you spend money on your kids, on your community, on your schools."

You'll note that Mr. Gonzales tellingly depicts the Hispanic political philosophy as "you spend money on your kids," which is not at all the same as "you spend your money on your kids." The tax money this Hispanic activist wants to spend on Hispanics is largely earned by non-Hispanics.

If Republicans won't restrict immigration, they had better start thinking hard about sneakier ways to postpone the oncoming political deluge for a few decades. Aristotle pointed out that the inevitable problem with democracy occurs when the majority finally grasps they can vote themselves the wealth of the minority.

That can take quite awhile, fortunately. A VDARE.com donor in Texas, a state that does not have an income tax, suggested in an email:

"One of my theories is that Texas can hold on a really long time as a tolerably low-tax place for whites who can afford to insulate themselves, as it will be a long time before a majority could show up at the polls to push through an income tax necessary to start the wealth redistribution in bulk as in California."

Clever "poison pill" amendments can delay the point at which future liberal majorities can redistribute wealth unchecked. In 1993, my reader pointed out, Texas voters passed a referendum requiring that any income tax initiated by the legislature must be submitted to the voters for approval. My reader explained:

"The constitutional amendment elections are in odd years with no other races on the ballot. This year's turnout was eight percent, so no one even bothers to do an exit poll for demographic stats. I'm guessing it's mostly white people who show up to vote. "

On the other hand, he adds:

"This is actually bad because once Texas does flip all the way, things will be much farther along before many middle class whites feel any pain."

In the very long run, he guesses that the return of literacy tests for voting eligibility is the least unachievable way to disenfranchise enough Democrats to keep the country from keeling over.

That's a good idea to keep in mind.

Of course, it would be simpler to win the battle for patriotic immigration reform now.

[Steve Sailer (email him) is movie critic for The American Conservative. His website www.iSteve.blogspot.com features his daily blog. His new book, AMERICA'S HALF-BLOOD PRINCE: BARACK OBAMA'S "STORY OF RACE AND INHERITANCE", is available here.]