Monday, December 04, 2006

California & Global Warming

The devil is in the details, which are now beginning to emerge from the strange bill California passed, whose effect might turn out not so bad as it increases the discussion of the issue and brings it to the deliberation of the Supreme Court, further deepening the discussion.

Meeting greenhouse gas limit might be tricky
The state must reduce emissions to a 1990 level that's uncertain.
By Edie Lau - Bee Staff WriterPublished 12:00 am PST Monday, December 4, 2006

As California carries out a new mandate to cut global warming pollution, its progress will be measured against its greenhouse gas output in 1990 -- the target point the state must reach by 2020.

That may sound simple enough. But, like California itself, figures for that benchmark year rest on ever-shifting ground.

Over the past decade, five state reports attempting to quantify 1990 emissions give five different numbers -- ranging from 425 million metric tons to 468 million metric tons of greenhouse gases.

Gerry Bemis, a California Energy Commission civil engineer who compiled the most recent inventory of greenhouse gas emissions, said the numbers will always be at least a bit squishy.

"As information and ... estimating techniques improve over time, estimate emissions for a selected year can and will change," he wrote. " ... The 'exact' value for 1990 will always remain unknown."

That fact illustrates the challenge ahead as the California Air Resources Board figures out how to extract meaningful reductions of climate-changing gases from industry.

"They have a great deal of work to do," said Energy Commissioner Jeffrey Byron, whose agency until now was in charge of tracking state greenhouse gas sources.

Passage this year of the landmark Assembly Bill 32 gave that job to the air board as part of a far-reaching effort to limit California greenhouse gases.

In adopting AB 32, the Legislature made California the first state in the nation to tackle climate change by mandate, although many countries around the world -- particularly signatories to the Kyoto Protocol -- are well under way with such efforts.

Greenhouse gases such as carbon dioxide are so called because, like the windows of a greenhouse, they trap heat in the atmosphere.

Produced naturally as well as by human activities such as burning fossil fuels, these gases, as they accumulate in the atmosphere, raise the planet's overall temperatures. That increase has the potential to cause significant changes in climate, including more frequent episodes of severe weather such as heat waves, droughts and hurricanes.