WASHINGTON — An obscure but important agreement to limit black carbon emissions, a particularly strong climate pollutant that accelerates melting of glaciers and sea ice, entered into force on Monday in Europe and North America.
The agreement, an amended version of the Gothenburg Protocol, regulates black carbon, or soot, which has a far higher global warming potential — a measure of the amount of heat that greenhouse gases trap in the atmosphere — than carbon dioxide.
A total of 51 countries, including many members of the United Nations Economic Commission for Europe, or UNECE, signed onto the amended treaty, but not all ratified it.
The amendment took effect with ratification by the European Union and 18 countries: Bulgaria, Canada, Croatia, Cyprus, Czechia, Finland, Germany, Latvia, Luxembourg, the Netherlands, Portugal, Romania, Slovakia, Spain, Sweden, Switzerland, the United Kingdom and the United States.
“The entry into force of the amended Gothenburg Protocol shows the continued commitments of the parties to pursue steady reductions in emissions,” said the treaty’s chair, Anna Engleryd, a senior policy advisor for the Swedish Environmental Protection Agency.
“Increased international interest demonstrates that our results are closely monitored in other regions, especially in Asia,” she said in a statement. “The entry into force also opens the door to negotiations to go even further in the fight for clean air.”
The Gothenburg Protocol was first established in 1999, setting legally-binding commitments to reduce emissions of major air pollutants. It grew out of UNECE’s Convention on Long-range Transboundary Air Pollution to fight acid rain. UNECE is one of five regional commissions of the U.N. Economic and Social Council.
The Protocol was amended in 2012 to further reduce, by 2020 and beyond, emissions of some major air pollutants: sulphur dioxide, nitrogen oxides, ammonia, volatile organic compounds and fine particulate matter, including black carbon — which is 680 times more powerful than CO2 at trapping atmospheric heat.
— UNECE (@UNECE) October 4, 2019
Fleeting but strong effect
Scientists know that black carbon has an important role in warming the planet, but studying its precise impacts has been difficult because it does not linger long in the atmosphere.
The end of the Little Ice Age, speeding the retreat of Alpine glaciers, has been linked to black soot from coal-burning factories, homes and steam locomotives in 19th century Europe. Soot particles that settle on snow and ice cause more heat absorption, hastening the melting process.
Cook stoves used by many of the world’s poorest people also produce large quantities of black carbon. Some cook stoves burn wood or dung, causing smoke clouds that add to breathing problems and glacial melting.
The United Nations’ Intergovernmental Panel on Climate Change, or IPCC, touched on the role of black carbon in a special report last month. The report said huge changes already are occurring around the 71 percent of the planet covered by oceans and 10 percent covered in ice and snow, known as the cryosphere.
The IPCC said changes in the oceans — damaged from absorbing at least 90 percent of the excess heat in air from carbon emissions — and in the cryosphere will lead to major ecological problems for the natural world and people around the globe, and wreak havoc on the world economy.
Glaciers hold large quantities of toxic chemicals, heavy metals and black carbon, the report said, which pollute drinking water as they are released from ice. Commercial shipping, it said, also mainly uses heavy fuel oil “with associated emissions of sulphur, nitrogen, metals, hydrocarbons, organic compounds and black carbon and fly ash to the atmosphere during combustion.”