Has Sen. Bennet really thought about immigration?

According to U.S. Sen. Michael Bennet's website, reforming immigration policy and combatting climate change are two of his key legislative goals.

But there is no evidence that the senator sees any connection between them, despite the fact that the U.N.'s Intergovernmental Panel on Climate Change has identified population growth as one of the two key drivers of global warming, and that most of the increase in U.S. greenhouse gas emissions in the past two decades has occurred due to population growth, while per capita emissions have remained relatively flat.

While they have so far neglected to provide hard numbers, the Senate Gang of Eight proposes two changes that would greatly increase America's population. First, an immense amnesty covering up to 12 million illegal immigrants, who would then be able to bring in tens of millions of relatives under current "family reunification" rules. Second, a huge increase in legal immigration, among both unskilled and skilled workers.

Together, these changes could increase immigration into the U.S. by 1 million annually, to as many as 2.25 million people annually. Using Census Bureau forecasting methods, here are projections for U.S. population growth during this century:

• 250,000 annual immigration = 379 million in 2100;

• 1.25 million annual immigration = 524 million in 2100; and

• 2.25 million annual immigration = 669 million in 2100;