Kyoto harms the ozone layer....

A very bad unintended consequence.....

Kyoto is meant to curb emissions of the greenhouse gases blamed for global warming, but is undermining a separate pact called the Montreal Protocol, meant to phase out gases which harm the earth's ozone layer.

That layer in the atmosphere shields the planet from damaging ultra-violet rays that can cause skin cancer.

At the heart of the clash is a carbon trading scheme under Kyoto, worth $5 billion last year, whereby rich countries pay poorer ones to cut greenhouse gas emissions on their behalf, called the clean development mechanism (CDM).

The most popular type of project has been to destroy a potent greenhouse gas known as HFC 23, one of a family of so-called hydrofluorocarbons, in China and India.

The problem is that HFC 23 is a waste product in the manufacture of a refrigerant gas which damages the ozone layer, called HCFC 22, and chemical plants have used their CDM profits to ramp up production.

"This is certainly one of the major drivers now in the increase in production of HCFC 22," Rajendra Shende, director of ozone issues at the United Nations Environment Programme, which administers the Montreal Protocol, said on Monday.

HCFC 22 now risked undoing recent repair to the ozone layer, Shende said in an interview.

Chemical plants have used CDM profits to cut the sale price of HCFC 22, pricing out alternatives that don't deplete ozone such as carbon dioxide and ammonia.

"(U.N.) bodies need to work more together, to see the actions of one don't risk the actions of another," Shende said.

Governments signed up to the Montreal Protocol will likely vote next month to accelerate the complete phase out of HCFC 22 in developing countries by 2025 or 2030 from 2040 now, he said.

CDM projects which destroy HFC 23 are especially lucrative because the gas is 12,000 times more potent a greenhouse gas than carbon dioxide (CO2), although its overall contribution to climate change is far less because CO2 is much more common.

As a result, destroying HFC 23 spawns far more money-spinning carbon credits than any other way of curbing greenhouse gas emissions.