Dieselization only a small part of global C[O.sub.2] stabilization strategy

Diesel Fuel News, Sept 15, 2003

Dieselization Only A Small Part of Global C[O.sub.2] Stabilization Strategy: If human-caused global warming emissions are really as big a threat as some claim--and if it's necessary to cut C[O.sub.2] concentrations to 1990 levels--then get ready for the world's biggest headache. The world would need to cut 1,300 gigatons of carbon emissions--a mind-boggling amount--just to maintain "business as usual" C[O.sub.2] levels by 2100, as Pacific Northwest National Laboratory's global change research institute's Charlotte Geffen showed here.

"Business as usual" (BAU) means C[O.sub.2] concentrations "only" double by 2100, rather than skyrocket under an "uncontrolled" emissions trend during this century. "BAU" assumes deployment of best-available technologies and major efficiency improvements, not just in vehicle C[O.sub.2] but also across industries and homes. Still, the "business as usual" challenge is staggering: Cutting just one gigaton would require installing C[O.sub.2] sequestration on roughly seven times the capacity of all the fossil-fired electric generation built in the U.S. in the last 20 years, or 1,500 one-gigawatt nuclear plants (more than three times all the nukes on the planet today). It also would mean planting nearly six times the acreage devoted to corn in the entire U.S., just to get one measly gigaton of carbon reduction via "biofuels." Multiply this challenge by 1,300 just for "business as usual" C[O.sub.2] levels. Bringing ambient carbon back to 1990 levels would require another 480 gigatons of carbon reduction. Meantime, world vehicle population is expected to skyrocket to 3.5 billion by 2050, up from 600 million today. Even if low-carbon diesels were to conquer 100% of the new-car market, they'd only cut transport C[O.sub.2] growth by 23%, or 225 million tons of C[O.sub.2] by 2100. More: Even if fuel economy hits 60 miles per gallon average, U.S. vehicle C[O.sub.2] emissions totals would still triple in the 21st century thanks to fleet and mileage growth. Hydrogen isn't the "cure-all" either as its production would require conversion of methane, coal, oil, biomass and vast quantities of electricity, all giving off C[O.sub.2] emissions in the process. Hydrogen fleets could cause local fog (due to vast amounts of water vapor emission), local atmospheric impacts and other unknown side-effects. "Climate policy will not necessarily make the hydrogen market," Geffen said. "Things have to compete in the marketplace to make a difference."