2.10 Making Connections

Methyl Bromide and Ozone Depletion

Background: In 2004, the Montreal Protocol banned widespread use of another chemical called methyl bromide (MeBr), which also destroys ozone. While some 27-42% of MeBr comes from natural sources such as oceans and soil, additional MeBr is released as a result of human activity. In Canada, MeBr is used primarily as a broad-spectrum pesticide. MeBr is not manufactured here.

Chemical companies insist that making effective substitutes for all uses of MeBr is not currently possible, and farmers maintain that relying on less effective alternatives will pose economic hardships. These groups also point out that MeBr has a much shorter atmospheric lifetime (0.7 years compared to 100 years for CFCs), a lower ozone depletion potential, and the production of MeBr has been steadily declining anyway (from 12 994 metric tons in 2004 to 1803 metric tons in 2010). In contrast, environmental advocates want a complete ban on MeBr.

Case: You have been assigned the task of developing a policy for the future use of MeBr. Your team must evaluate various options such as:

1. A complete ban on all anthropogenic sources of MeBr and switching to Environment Canada-approved alternatives (www.ec.gc.ca/toxiques-toxics/Default.asp?lang=En&n=98E80CC6-1&xml=B5655CBB-5B04-4D86-ADFC-BC480C437E12) even if this switch comes at a cost.
2. A continuance of the current ban on non-essential uses with exemptions for critical uses approved on an annual basis. (See www.ec.gc.ca/lcpe-cepa/default.asp?lang=En&n=F14675FC-1&offset=1&toc=show#_ftn2 for exemption criteria).

Research these (and possibly other) options and write a report recommending a course of action. In your report include the following:

1. An analysis of the pros and cons of each proposal including: a discussion of the consequences of each choice for stratospheric ozone depletion, human health, food availability and prices, and the economics of farming.
2. Based on the information at hand, what is the best course of action for the future of MeBr? Who should be involved in making this decision? Provide justifications for your proposal.