SEI scientists coordinate new UNEP-WMO climate study
Complementary action to curb ‘soot’ and ‘smog’ pollution could help limit global temperature rise to 2 degrees or less
Press release June 14, 2011
Fast action on pollutants such as black carbon, ground level ozone and methane may help limit global temperature rise in the near future and significantly increase the chances of keeping temperature rise below 2 degrees C says a new assessment launched today in Bonn, Germany.
Stockholm Environment Institute has coordinated the new United Nations Environment Programme (UNEP)/World Meteorological Organization (WMO) assessment on reducing the impact of black carbon and tropospheric ozone that adversely affect public health, crop yields and contribute to climate change.
The study concludes that protecting the climate in the near future is central significantly cutting the risk of “amplified global climate change” linked with the rapid and extensive loss of Arctic ice, both on land and at sea.
Fast action might also reduce losses of mountain glaciers linked in part with black carbon deposition while reducing projected warming in the Arctic over the coming decades by two thirds. Scientists also point to numerous public health and food security opportunities above and beyond those linked with tackling climate change.
Big cuts in emissions of particulate matter through implementation of measures to reduce black carbon emissions will improve respiratory health and reduce hospital admissions and days lost at work due to sickness, says the assessment whose Secretariat is provided by the Stockholm Environment Institute. Close to 2.5 million premature deaths from outdoor air pollution could on average be avoided annually world-wide by 2030, with many of those lives saved being in Asia, the assessment estimates.
Cutting ground level ozone could also contribute to reduced crop damage equal to between one and four per cent of the annual global maize, rice, soybean and wheat production.
Reducing these so-called ‘short-lived climate forcers’ can have immediate climate, health and agricultural benefits, the report concludes. Unlike carbon dioxide (CO2) which can remain in the atmosphere for centuries, black carbon only persists for days or weeks.
The researchers also underline the fact that while fast action on black carbon and ground level ozone, especially through targeting its precursor methane, could play a key role in limiting near-term climate change, immediate and sustained action to cut back CO2 is crucial if temperature rises are to be limited over the long-term.
The report concludes that a combination of action on short-lived climate forcers and long-lived greenhouse gases will improves the chances of keeping below the 2 degree target throughout the 21st Century.
The findings, released today in Bonn, Germany during a meeting of the UN Framework Convention on Climate Change (UNFCCC), have been compiled by an international team of more than 50 researchers chaired by Drew Shindell of the National Aeronautics and Space Administration (NASA-GISS).
The team included researchers from Stockholm Environment Institute, led by Dr Johan Kuylenstierna, who was scientific coordinator and a lead author. SEI researchers Dr Kevin Hicks and Dr Harry Vallack were also lead authors and Dr Lisa Emberson was coordinating lead author of the chapter on impacts.
Dr Kuylenstierna said: “In addition to the global benefits of reducing short-lived climate forcers, the regional nature of the benefits of reducing black carbon and tropospheric ozone should appeal to policy makers. The biggest impacts of emission reductions are seen in the regions where action is taken. This is especially true for public health, but also follows for crop yields and regional climate impacts”.
“Most promising of all is that solutions exist. The challenge that remains is one of strategic planning, financing and policy focus,” he added.
Achim Steiner, UN Under-Secretary General and UNEP Executive Director, said: “There are now clear, powerful, abundant and compelling reasons to reduce levels of pollutants such as black carbon and tropospheric ozone along with methane: their growing contribution to climate change being just one of them”.
“This assessment underlines how the science of short-lived climate forcers has evolved to a level of maturity that now requires and requests a robust policy response by nations. The experts spotlight how a small number of emission reduction measures — targeting for example recovery of methane in the coal, oil and gas sectors through to the provision of cleaner burning cook stoves; particle traps for diesel vehicles and the banning of open burning of agricultural wastes — offer dramatic public health, agricultural, economic and environmental benefits,” he added.
The UNEP/WMO Integrated Assessment of Black Carbon and Tropospheric Ozone suggests that action could be catalyzed not only through the UN climate convention process but also, for example, by strengthening existing national and regional air quality agreements.
Michel Jarraud, Secretary-General of the WMO, said: “Most attention is focused on reducing the main greenhouse gas, CO2, to combat climate change. However in recent years it has become clear that a range of other pollutants such as black carbon and tropospheric ozone are aggravating the challenge”.
“This report underlines the need for a stronger observational basis and research effort to increase scientific understanding of the role of these other pollutants in the changing climate system. WMO’s Global Atmosphere Watch Programme is addressing these challenges as a priority,” he added.
Drew Shindell of NASA’s Goddard Institute for Space Studies said: “This report has brought clarity to the complexity of the heating and cooling effects of a range of pollutants and uses science to show that there are clear and concrete measures that can be undertaken to help protect the global climate in the short to medium term”.
“Perhaps the most intriguing link is between emissions of methane and the formation of tropospheric ozone. Methane is a powerful greenhouse gas in its own right, but it has emerged that it is also triggering a great deal more global warming by contributing to the formation of significant levels of ground level ozone — indeed more than was previously supposed. The win-win here for limiting climate change and improving air quality is self-evident and the ways to achieve it have become far clearer as a result of this assessment,” he added.
Today the Government of Sweden announced support for a comprehensive and forward-looking policy assessment to assist governments on the next steps towards fast action on short-lived climate forcers (SLCFs). This is line with Sweden's strategy on SLCFs and its policy to integrate climate change and air pollution policies.
The work, to be coordinated by UNEP, is expected to be ready in advance of the next Climate Convention meeting scheduled later in the year in Durban, South Africa.
For More Information Please Contact:
Nick Nuttall, UNEP Spokesperson/Head of Media, on Tel: +254 733 632755, email:
Clare Nullis, WMO Press Officer, on Tel: + 41 22 730 8478, email:
Ylva Rylander, SEI Head of Press, on Tel: +46 73 150 3384, email:
The summary for decision makers and full UNEP/WMO Integrated Assessment of Black Carbon and Tropospheric Ozone report can be found at www.unep.org
The UN Climate Change Conference June 2011 unfccc.int/2860.php
UNEP’s work on climate change www.unep.org/climatechange/
WMO, the U.N. system’s authoritative voice on weather, water and climate, www.wmo.int
Stockholm Environment Institute, bridging science and policy, www.sei-international.org
Stockholm Environment Institute is an independent international research institute. SEI has established a reputation for rigorous and objective scientific analysis in the field of environment and development. SEI aims to bring about change for sustainable development by bridging science and policy. Further information at www.sei-international.org.