Want to save $12 trillion? Get off the oil economy. That was the blunt message from a recent report showing that the worst of climate change could be contained by investing 1% of global GDP into energy efficiency, green power and preventing deforestation by 2030.

The do-nothing alternative is somewhat less of a wise investment. Nicolas Stern, the former Chief Economist for the World Bank found that ignoring climate change would cost the world economy up to 20% of global GDP due to lost productivity, extreme weather and water shortages.

This latest report was conducted by the international consulting firm McKinsey & Company on behalf of a number of disparate groups concerned about climate change including Shell Oil, Honeywell and the World Wildlife Fund.

Global GDP is now about $65 trillion. Doing the math on potential savings works out to a tidy $12 trillion and change. For those unaccustomed to such astronomical sums, that would be a stack of $1,000 bills about 750 miles high.

Beyond the mountain of cash, there are a number of other benefits getting that oily monkey off our back. Over 3 million people worldwide perish each year from air pollution – three times as many as die in traffic accidents. Asthma costs the US economy over $10 billion annually.

The war in Iraq – which many attribute to our addiction to oil – may cost the US economy a staggering $3 trillion. Over 4,200 US service personnel have lost their lives and almost 44,000 have been wounded. The Lancet estimated in 2004 that more than 650,000 Iraqis had lost their lives due to the invasion.

The report from McKinsey also stresses the need the preserve tropical forests to conserve carbon emissions. Saving these areas from the saw would also protect natural biodiversity that is disappearing at startling rate.

Tropical forests contain 170,000 of the world's 250,000 known plant species. One study in Brazil found that a single hectare of forest contained 487 species of tree. In contrast, all of Canada and the US contain only 700 tree species.

Rainforest habitat is a cornucopia of biological diversity representing millions of years of years of evolution. While 25% of Western pharmaceuticals are derived from rainforest ingredients, less than 1% of these tropical trees and plants have been tested by scientists.

Last year researchers in the journal Frontiers in Ecology and the Environment stated grimly that “we are already squarely in the midst of a tropical biodiversity tragedy and on a trajectory toward disaster."

The laundry list of important reasons to ditch the oil economy just got a little longer. Preserving hundreds of millions of years of biodiversity, reducing deadly and expensive air pollution, eliminating the need for costly and tragic military operations.

Oh yeah, then there’s that stack of thousand dollar bills 750 miles high…