Study brings the `greenhouse effect' home. Environmentalists hope public will look at local causes of global warming

Coming soon to a town near you: global warming. As scientists worldwide debate the existence and possible consequences of a greenhouse effect, and the global warming that goes with it, one environmental group is trying to localize the discussion.

In a study released yesterday, the Washington-based group Renew America documents how much carbon dioxide - a key ``greenhouse gas'' - each of the 50 states produces, and which sectors of the economy are most responsible for the emissions. The report also highlights data that provide some indication of which states face the most severe challenges from methane emissions and tropospheric ozone - two other greenhouse gases.

State-by-state comparisons of the data are largely irrelevant, as population and industrial activity rather than geographical area determine the amount of carbon dioxide released by a given state. But the report's authors hope the information will stimulate interest in responding to the greenhouse effect at the local level.

``We want people to be more aware that greenhouse gases are not something vaguely `up there,''' says Rick Piltz, co-author of the report, ``but that they are tied to specific sources which need to be accountable for emissions.''

``There is no way to say at this point that one state is doing the best job'' in responding to the greenhouse effect, he adds.

The report also recommends numerous steps that could be taken to decrease any threat of global warming by increasing energy efficiency.

Most of the recommendations - including tougher standards for automobile fuel efficiency and energy efficiency in buildings, broader government support for public transportation - embrace long held views of energy efficiency advocates. ``A lot of it is nothing new,'' Piltz admits.

Still, the threat of a greenhouse effect adds urgency to the push for greater energy efficiency, he says.

In addition, the report suggests, combating the greenhouse effect could require not only reductions of carbon dioxide at the source, but efforts to reduce levels of carbon dioxide overall. The report recommends consideration be given to reforestation and ``strategic'' tree-planting to shade buildings and pavement, thus cooling ``heat islands'' and reducing energy demand.

Meanwhile, a World Resources Institute study, also released yesterday, finds the US is one of the world's least energy-efficient countries.

The report says the US uses twice as much energy as Japan does to produce a dollar of gross national product. Of the world's 10 largest economies, US energy efficiency is superior only to that of China, India, and Canada, the report says.