Less Snow, More Climate Scientists
by Bill Rudolph
The region took a break from the wrangling over summer spill earlier this month when the Northwest Power and Conservation Council tiptoed into the global warming debate after hearing a presentation by University of Washington scientist Phil Mote.
Citing evidence from tree rings and coral growth, Mote told the council that "it's pretty clear that temperatures in the last third of the 20th century are higher than they've been in the last thousand years." He noted the rate of temperature change is also increasing.
Mote said a UW computer model shows that flows in the Snake River at Ice Harbor will likely increase in winter and decrease during summer months because higher temperatures would mean less snow is stored in lower elevations. Peak flows in rivers will occur earlier, with the potential for more hydro operation in the winter, "and all sorts of problems with reduced flow in the summer--shortages for irrigation, fish and hydro."
June and July flows could drop 25 percent to 30 percent from base flows, he added, on the order of 25,000 cfs.
The global temperature analysis didn't prove humans were influencing climate, Mote said, but graphs of greenhouse gases like CO2 show a build-up with a similar shape and "should give us broad pause."
Climate models show that the troposphere is warming faster than the earth's surface, Mote said, but satellite measurements show no trend on the surface. However, balloon measurements show the possibility that a warming has been taking place since the 1970s. And the rate of warming, he said, exhibits a spatial pattern that scientists would expect from greenhouse gases.
Mote told the council that many scientists doubt this warming trend is coming from differences in energy output from the sun, which shows little variation in the two complete cycles that have been observed since 1978--only about 0.1 percent. Furthermore, since most of the change in the sun's energy is ultraviolet, it is readily absorbed into the stratosphere. "The amount of solar radiation reaching earth has not varied at all in the last 30 years," Mote said.
The UW scientist says evidence points to human influences affecting climate for the past 50 years, and indicates even more influence over the next 100 years. However, even if more sustainable energy choices are added in the future, and the developing world's growth slows, Mote said CO2 levels would double pre-industrial levels to about 550 ppm. A faster developing world still using lots of fossil fuels would boost CO2 levels to around 1000 ppm. For the Northwest, he said several climate models predict an average warming of 4 degrees Celsius.
Mote said a hydrologic model developed at UW using a moderate warming rate estimates 35 percent less snowpack in warmer areas like the Cascades and southern Idaho by the 2050s. By the 2090s, the model predicts 47 percent less snowpack, with very little snow left in the Oregon Cascades.
"This is pretty much what we're seeing already," Mote said. "That the declines are happening faster in the Cascades and less fast in the colder mountains." Though the models all point to future warming in the Northwest, they can't tell whether precipitation levels will go up or down.
The council also heard from consultant Mark Trexler of Trexler Associates, who discussed implications of climate change on energy policy. "It probably makes sense for states to be thinking about those impacts," Trexler said, citing new CO2 siting standards in Oregon and Washington along with technological-forcing legislation in California with automobiles.
In the international arena, Trexler said it was about an even bet whether Russia signs the Kyoto Protocol for reducing greenhouse gas emissions. The protocol calls for most countries to reduce greenhouse emissions by 5 percent from 1990 levels. One hundred parties have ratified the protocol so far, Trexler said, when only 55 were needed, "but without either US or Russian ratification, it won't come into force."
As for individual countries, he noted that Canada is working towards reducing emissions through negotiations between the federal government and individual companies to set targets, leading to possible domestic emissions trading.
Japan is also a strong supporter of the protocol. "But the Japanese are in a tough position," Trexler said, with a stagnant economy, "and also faced, in a sense, with becoming a province of the Chinese economy." He said Japan's original strategy called for building 13 new nuclear power plants by the end of this decade, which now won't happen, partly because of the recent nuclear scandal in that country. So far, Japan has instituted a small coal tax, about $2 per ton rising to about $7 per ton in 2007.
European nations are also strong supporters of emissions trading. Trexler said a $5 per ton CO2 tax on coal would add about half a penny to a coal-fired kilowatt-hour. "In a European context, that's viewed as totally acceptable."
Trexler said the CO2 "intensity" of the U.S. economy has been going down about one percent a year over the past 10 years without any incentives. That has occurred for a variety of reasons, including an overall trend in the economy toward more of a service orientation. More efficient appliances have also played a role.
West Coast governors are working on an initiative to reduce emissions, but it's still in a formative stage, Trexler said. New England governors have already established an official target of getting back to 1990 emissions level by 2010 and below 1990 levels by 2020.
However, to simply stabilize CO2 emissions (30 percent above pre-industrial levels), global emissions would have to be reduced by about 70 percent, said Trexler, who pointed out that the Kyoto agreement would not actually reduce emissions, but only slow their growth a bit. Even though industrialized nations would cut their emissions, developing countries would still be increasing their own levels.
"To talk about 70 percent reduction in global emissions . . . you don't even put it on the political plate very often because it's so far beyond the pale," Trexler said. Doing that would obviously revolutionize the world's energy systems, he told the council. As for future costs, he reported that modelers at Stanford University have estimated that it would cost about ten cents per KWh for a coal plant to reach this goal.
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