The Climate Change Bill must say that we should aim for at least a 80% cut in carbon emissions by 2050.
Last week's UN human development report called for such a target for the richer countries.
Speaking to the Royal Economic Society last Friday, Nicholas Stern underscored this: "For a global 50% reduction in emissions by 2050, the world average per capita must drop from 7 tonnes to 2-3 tonnes.
"An 80% target for rich countries would bring equality of only the flow of emissions around 2-3 tonnes per capita.
"In fact, rich countries will have consumed the big majority of the 'available space in the atmosphere'."
In other words, if we are to achieve an equitable world agreement on carbon reductions, we have to commit to cuts of 80% or more.
This should therefore be in the Climate Change Bill.
The same is true in the States, where the Senate Committee on the Environment and Public Works Committee yesterday passed the Lieberman (D-Conn.) and John Warner (R-Va.) sponsored climate change bill that would establish the first US nationwide cap-and-trade system to reduce global warming gas emissions.
The bill now moves to the Senate floor. The decision sends a positive message to the Bali talks about America's willingness to accept responsibility for climate change.
But even with aggressive action by developing countries and other industrialized nations, the United States must cut its emissions at least 80 percent below 2000 levels by 2050, argues the Union of Concerned Scientists.
They say that in its current form the bill gets about three-quarters of the way there.