Nothing dumb about it. Environmental impact is regarded as an externality by modern markets. Denmark has monetized that externality. If your shareholders demand yield but your stakeholders demand corporate responsibility, you buy a Rio Tinto cyanide-stripping gold bond for the shareholders and green certs from Denmark for the stakeholders and get on with your day.

Milton Friedman argued that if citizens were serious about the environment they'd pass laws to make environmental pollution illegal because the economic incentive for corporations is to rape the environment to the fullest extent of the law. Denmark has effectively issued a bond that allows you to set an economic price on the idea of environmentalism, rather than the actualization of environmentalism, and whatever monies it collects, some journalist somewhere will ask what it's being spent on.

Compare and contrast with the credit default swap:

- "I would like to speculate on the price of the insurance issued to hedge the odds of a bond I don't own defaulting"

or the collateralized debt obligation:

- "I would like to underwrite a percentage of the fourth decile as determined by synthetic risk assessment of all single-family mortgages written in the Great Plains by Washington Mutual between January 2005 and January 2006"

or the synthetic collateralized debt obligation:

- "I would like to speculate on the underwriting of a percentage of the fourth decile as determined by synthetic risk assessment of all single family mortgages written in the Great Plains by Washington Mutual between January 2005 and January 2006."

All sorts of investment vehicles are dumb. They make money anyway. In 2000, "nickels in front of steamrollers" was a cautionary tale. By 2006 it was a forex strategy. Now? Now it's the fundamental basis of 85% of the market. "zero coupon bond with zero redemption at maturity" sounds stupid if you think it's a bond but you sound stupid if you think bonds have been bonds for the past twenty years. You're speculating on whether you think people believe Denmark will continue to feel environmentally conscious. It's a sentiment market available to hedge your Alcoa stock, nothing more.