Canada - United States Air Quality Agreement Progress Report 2014: introduction

Introduction

In 1991, the United States and Canada established an Air Quality Agreement (AQA) to address transboundary air pollution. The Agreement initially focused on reducing levels of acidic deposition in each country, and in 2000 the Agreement was amended to also address ground-level ozone (O₃). A bilateral Air Quality Committee, established in the Agreement, is required to issue a progress report every two years, highlighting the commitments included in the AQA and describing the continued efforts by both governments to address transboundary air pollution. This document is the twelfth such progress report under the AQA.

In this report, Canada and the United States document the large reductions in sulphur dioxide (SO₂) and nitrogen oxide (NO_x) emissions that have been achieved to date, along with the associated reductions in ecosystem acidification and improvements in air quality. Between 1990 and 2012, emissions of SO₂ declined by 58 percent in Canada and 78 percent in the United States. The report also provides information on successes in reducing emissions of NO_x and volatile organic compounds (VOCs), the precursors to O₃, in the transboundary ozone region. Between 2000 and 2012, Canada’s total NO_x emissions in the region decreased by 45 percent, while in the United States total NO_x emissions in the region declined by 47 percent.

The report also describes scientific and technical cooperation and research under way between the two countries, and provides an update on new actions in each country that will help further reduce levels of acid rain, O₃ and particulate matter (PM). These efforts signify the ongoing importance both countries place on cooperation and innovation in addressing transboundary air pollution issues.