The 1987 Montreal Protocol on Substances That Deplete the Ozone Layer is considered the most successful environmental treaty. As a result of this accord, worldwide production and use of ozone-depleting chemicals has declined sharply, and the hole that had formed in the stratospheric ozone is expected to begin healing within a few decades.
However, a number of trends are under way that may partially undermine the success of the treaty, particularly surrounding the use of methyl bromide. There are many indications that production and use of this ozone-depleting fumigant reached a low point in 2003 and is beginning to climb.
The parties to the Montreal protocol agreed in 1995 to phase out use of methyl bromide in developed countries by 2005 and in developing countries by 2015. The protocol does allow highly restricted exemptions for critical uses--exemptions that are granted when no effective, economically feasible alternative is available.
In the U.S., methyl bromide consumption declined sharply from 1991 to 2003, but now use of the fumigant could increase. In 2003, according to Environmental Protection Agency figures, the U.S. used 7,674 metric tons, primarily on agricultural soils. This was 30% of the U.S. 1991 baseline level of 25,528 metric tons. During 2004, the U.S. used at least 7,658 metric tons, but more could have been used--it would have been drawn from stockpiles and thus not reported to date. And, for 2005, negotiators at a conference of the parties to the Montreal protocol in Prague last November agreed that the U.S. could consume 9,445 metric tons, or 37% of the baseline level. At that meeting, the U.S. requested the same allotment for 2006, but no agreement was reached.
The U.S. claims that it needs the 9,445 metric tons for 2005, and a similar amount for 2006, primarily for soil fumigation in the cultivation of strawberries, tomatoes, and peppers in Florida and California. Altogether, the U.S. will consume more than half the total exemptions (14,750 metric tons) granted to 15 developed countries for 2005.
Methyl bromide is used for soil fumigation before the planting of various fruits and vegetables and in agricultural nurseries. Although there are many substitutes for methyl bromide, no single chemical is as broadly effective. Often two or three substitutes need to be used in place of one treatment with methyl bromide. This is why farmers have fought to preserve use of the chemical. The U.S. Department of Agriculture and trade groups say a phaseout of methyl bromide in 2005 will place U.S. farmers at an economic disadvantage in the short term because developing countries do not have to phase out the fumigant until 2015.
Environmental activists oppose the decision permitting increased methyl bromide use in the U.S. as a dangerous step in the wrong direction. "The disturbing conclusion is that the U.S., which used to be the world leader in protecting the ozone layer, is actually working to increase the amount of ozone-depleting chemicals that are released each year," says David Doniger, policy director of the climate center at the Natural Resources Defense Council. "It makes no sense for the U.S. to request permission to use more methyl bromide in 2005 and 2006 than it used in 2003."
"Repeated requests for large exemptions from phaseout violate the spirit and text of the treaty," says R. Juge Gregg, senior campaigner at the Environmental Investigation Agency (EIA), based in Washington, D.C., and London.
The parties to the treaty will meet in an extra session in June or July to decide on the exemptions for the U.S. in 2006. "It is truly sad that because of the behavior of the U.S., we've had to have extraordinary meetings that never happened before under the Montreal protocol," Gregg says.
However, the U.S. State Department claims that all the exemptions it requested are absolutely necessary. In regard to exemptions for 2006, Claudia A. McMurray, deputy assistant secretary of state for the environment, said in a statement, "We have submitted an exemption request only for what our farmers need, as the protocol clearly allows, and nothing more."
There is another retrograde trend for ozone-layer protection. In many parts of the world, methyl bromide is used to kill insects in rice, maize, and other grains before the grains are shipped and to fumigate shipping pallets made of raw wood, which often harbors insects. Methyl bromide's use for quarantine and preshipment seems to be rising sharply as international trade increases. These uses are specifically exempted under the protocol and are not subject to phaseout requirements. But parties have agreed to some fuzzy treaty language encouraging them to reduce quarantine and preshipment uses of methyl bromide.
ACCORDING TO United Nations estimates based on an incomplete survey, about 11,000 metric tons of methyl bromide were used for quarantine and preshipment treatments in 2002, and by 2004, this use had grown to about 18,000 metric tons. These numbers are considered to be underestimates because not all countries have yet supplied precise figures. At the November meeting in Prague, the parties agreed to provide complete data to the UN so the survey can be finished. This may be a first step toward controlling use of methyl bromide for these purposes.
While the Montreal protocol aims to discourage the use of methyl bromide, another international agreement is encouraging its use. The International Plant Protection Convention recently adopted guidelines for treating raw wood packaging material in international trade, requiring treatment with heat or methyl bromide only. However, many alternative treatments are effective in some situations, such as sulfuryl fluoride, ethylene oxide, and phosphine, or alternative packaging materials can be used, Doniger says. Nonetheless, many countries around the world--including the U.S.--are passing regulations to implement the international standard.
USDA proposed a regulation requiring that all raw wood packing crates coming into or leaving the U.S. must be treated with heat or methyl bromide. USDA expects that most countries, especially those in the developing world, will favor methyl bromide because it is much cheaper than heat. The rule allows continued unlimited use of raw wood packaging, which is now employed in an estimated 70% of international shipments. Doniger suggests that pallets made of plastic or plywood or some other kind of manufactured wood that would not have to be fumigated could be used in place of raw wood pallets. Most of these alternative materials could be reused.
USDA has some projections of the amount of methyl bromide that might be required for preshipment of most raw wood pallets used around the world. In an environmental impact statement, the agency estimates that methyl bromide use for treatment of pallets worldwide would range from a low of 10,000–20,000 metric tons up to 100,000 metric tons per year. An amount at the high end of the range would double the current global usage of methyl bromide, Doniger says.
At the extra conference of the parties this summer, there is likely to be much discussion of the alternative agricultural treatments the U.S. could use instead of methyl bromide. Also, progress is likely on the survey of quarantine and preshipment uses of methyl bromide. But unless something can be done about the increasing use in pallet fumigation, consumption of this chemical will continue to rise.