IPCC 1.5°C Report: Reducing Short-Lived Climate Pollutants necessary to achieve 1.5°C climate goal

by CCAC secretariat - 8 October, 2018
The special report 'Global Warming of 1.5°C' says emissions of methane and black carbon need to be reduced by 35% or more by 2050

A much anticipated report by the United Nation’s Intergovernmental Panel on Climate Change (IPCC) shows there is still a long way to go if we want to limit global temperature rise to 1.5 degrees Celsius and prevent dangerous warming. But the report also shows that there are ready-to-go solutions that can help us achieve the target, rapidly reduce the rate of warming, and prevent millions of premature deaths from air pollution each year.

Our best chance to avoid runaway warming is to act right away to reduce highly potent but short-lived climate pollutants (SLCPs) like methane, tropospheric ozone, hydrofluorocarbons (HFCs) and black carbon. This must go hand-in-hand with deep and persistent cuts in long-lived greenhouse gases like carbon dioxide (CO2).

Fast and immediate action on SLCPs can avoid over half degree of warming by 2050. It will also avoid over 50% of the predicted warming in the Arctic by 2050, thereby significantly decreasing the chances of triggering dangerous climate tipping points, like the irreversible release of carbon dioxide and methane from thawing Arctic permafrost.

Drew Shindell, Professor of Climate Sciences at Duke University and a lead author on the IPCC report, said no scenario exists where the world can get to 1.5 degrees without reducing these highly potent, but short-lived climate forcers alongside CO2.

“The report emphasizes that reaching low warming targets is so challenging that we need to use all the options at our disposal. Since they typically have relatively low costs, least-cost mitigation pathways tend to maximize SLCP reductions,” Dr Shindell said. “The IPCC Special Report also highlights how SLCP reductions contribute to many of the world’s sustainable development goals.”

There are also multiple non-climate benefits to action. Climate change and air pollution are closely interlinked, so reducing these pollutants not only protects the climate but also promotes clean air. Acting now can prevent two and a half million premature deaths from air pollution each year, and save more than 50 million tons of food crops annually. These tangible, often local, air quality benefits in-turn can increase the likelihood of public and institutional support for even more ambitious mitigation action.

Paragraph C1.2 of the Summary for Policy Makers of the IPCC Special Report: Global Warming of 1.5°C outlines the contributions SLCPs can make saying: “Modelled pathways that limit global warming to 1.5°C with no or limited overshoot involve deep reductions in emissions of methane and black carbon (35% or more of both by 2050 relative to 2010). These pathways also reduce most of the cooling aerosols, which partially offsets mitigation effects for two to three decades. Non-CO2 emissions can be reduced as a result of broad mitigation measures in the energy sector. In addition, targeted non-CO2 mitigation measures can reduce nitrous oxide and methane from agriculture, methane from the waste sector, some sources of black carbon, and hydrofluorocarbons. High bioenergy demand can increase emissions of nitrous oxide in some 1.5°C pathways, highlighting the importance of appropriate management approaches. Improved air quality resulting from projected reductions in many non-CO2 emissions provide direct and immediate population health benefits in all 1.5°C model pathways.”

The report shows there needs to be considerable cuts in emissions of black carbon (35% by 2030), methane (37% by 2030) and HFCs (70%-80% by 2050) if we are to keep warming below 1.5˚C. Dedicated reductions measures recommended by the Climate and Clean Air Coalition to reduce Short-lived Climate Pollutants (CCAC)  can deliver all recommended methane mitigation (and substantially more with new research for agricultural methane), a 60% reduction in black carbon emissions by 2030 (with up to 80% possible), and 90% reduction in HFC emissions by 2050 (relative to 2010) and greater energy efficiency in the cooling sector. 

Helena Molin Valdés, Head of the Climate and Clean Air Coalition Secretariat said the world can act now to reduce these pollutants by making maximum use of existing, cost-effective technologies that are already being implemented around the world.

“Without action on short-lived climate pollutants there is little chance to reach the Paris Agreement’s 1.5˚C goal. Reducing these pollutants must be done in addition to a fast switch to a low-carbon economy,” Ms. Molin Valdés said. “Short-lived climate pollutants are the ‘low hanging fruit’ in the fight against climate change. We have the tools and proven technologies and policies to help countries achieve immediate reductions, and by doing so we can solve air pollution and climate simultaneously.”

Existing solutions include replacing HFCs in refrigeration and air conditioning and properly disposing of them; reducing methane from waste streams (including food waste) and from agriculture; expanding clean cookstoves and phasing out black carbon emissions from heavy duty engines like trucks, buses and ships; and reducing methane leakage from oil and gas production.

David Waskow, Director of the World Resources Institute’s International Climate Initiative said reducing short-lived climate pollutants should be part of countries’ climate and development agendas.

Mr. Waskow said: “Countries have a clear opportunity to tackle this challenge by strengthening their commitments under the Paris Agreement by 2020. Taking action will have a measurable and immediate impact on global temperature rise in next 25 years while producing extraordinary benefits in public health and food security across sectors like energy, transport, and agriculture.”      

Last week, the World Resources Institute and Oxfam released a new working paper entitled Strengthening Nationally Determined Contributions to Catalyze Actions that Reduce Short-Lived Climate Pollutants, which presents a set of options for how targets, policies, and actions can be incorporated into NDCs.

Johan Kuylesntierna, Policy Director at Stockholm Environment Institute (SEI), said: "Given the importance of measures to reduce black carbon and methane, SEI is supporting countries using the LEAP-Integrated Benefits Calculator tool to allow them to understand the opportunities to reduce emissions, and the benefits to health and climate from doing so."

Nobel Laureate Dr Mario Molina said: “The IPCC report demonstrates that it’s still possible to keep the climate relatively safe, provided we muster an unprecedented level of cooperation, extraordinary speed, and heroic scale of action. It’s an essential template for world leaders to follow.  But even with its description of the increasing impacts that lie ahead with increasing warming, the IPCC report understates a key risk: that self-reinforcing feedback loops could push the climate system into chaos before we have time to tame our energy system and the other sources of climate pollution.

Dr Veerabhadran Ramanathan, Professor of Climate and Atmospheric Sciences, Scripps Institution of Oceanography, University of California at San Diego, said: “Climate change is an issue of fundamental data-driven science, an issue of human tragedy, and an issue of planetary ecosystems in peril. Above all, it is an issue we can still do something about, as the IPCC’s 1.5 report makes clear, including, critically, by cutting the short-lived super climate pollutants.”

Romina Picolotti, President of the Center for Human Rights and Environment – Ex Secretary of Environment of Argentina said: “The 1.5 C report is clear we are not going to make it if we do not reduce at scale these short lived climate pollutants. We have the technologies to do it, we can do it, the question is do we want to do it? And the answer to that question is we do not have a choice anymore if we want a future.” 

Durwood Zaelke, President of the Institute for Governance and Sustainable Development said: “Half a degree doesn’t sound like much until you put it in the right context. It’s 50 percent more than we have now. The idea of letting warming approach 2 degrees Celsius increasingly seems disastrous in this context.”

At the Global Climate Action Summit in San Francisco, USA, last month, Ola Elvestuen, Norway’s Minister for Climate and Environment, called on countries to endorse the Climate and Clean Air Coalition’s Talanoa Statement. The Statement highlights the need to raise ambition to reach the Paris Agreement 1.5 degree temperature target, and sets out how to achieve the urgent need to reduce the rate of near-term warming through fast cuts in short-lived climate pollutant emissions.

“It is not irrelevant how we reach the Paris temperature targets. To succeed in the long term we need to choose a path that will slow the rate of global warming in the near term,” Minister Elvestuen said. “By reducing both short and long-lived climate forcers we increase our chance of success.”

The statement recognizes that acting now will also support sustainable development and efforts to eradicate poverty


The Climate and Clean Air Coalition is the only global effort that unites governments, civil society and private sector, committed to improving air quality and protecting the climate in the next few decades by reducing short-lived climate pollutants. The Coalition supports the achievement of transformative actions, policies and regulations that lead to substantial reductions of these pollutants. There are 61 countries, 17 inter-governmental organizations, and 51 NGOs in the Coalition. Norway, Oxfam, and the World Resources Institute are partners. Drew Shindell is head of the Coalition’s Scientific Advisory Panel. The Coalition’s Secretariat is hosted by the United Nations Environment Programme.

Contact: Tiy Chung, Climate and Clean Air Coalition Communications Officer, tiy.chung [at] un.org, +33 6 26 71 79 81