Chapter 25 in Health of People, Health of Planet and Our Responsibility: Climate Change, Air Pollution and Health (Al-Delaimy, W. K., Ramanathan, & V., Sorondo, M. S. eds). Springer, Cham. Pages 321-331.
Climate change is becoming an existential threat with warming in excess of 2 °C within the next three decades and 4–6 °C within the next several decades. Warming of such magnitudes will expose as many as 75% of the world’s population to deadly heat stress in addition to disrupting the climate and weather worldwide. Climate change is an urgent problem requiring urgent solutions. This chapter lays out urgent and practical solutions that are ready for implementation now, will deliver benefits in the next few critical decades, and place the world on a path to achieving the long-term targets of the Paris Agreement. The approach consists of four building blocks and three levers to implement ten scalable solutions described in this chapter. These solutions will enable society to decarbonize the global energy system by 2050 through efficiency and renewables, drastically reduce short-lived climate pollutants, and stabilize the warming well below 2 °C both in the near term (before 2050) and in the long term (after 2050). The solutions include an atmospheric carbon extraction lever to remove CO2 from the air. The amount of CO2 that must be removed ranges from negligible (if the emissions of CO2 from the energy system and short-lived climate pollutants have started to decrease by 2020 and carbon neutrality is achieved by 2050) to a staggering one trillion tons (if the carbon lever is not pulled and emissions of climate pollutants continue to increase until 2030).
Chapter 15: Technologies for Super Pollutant Mitigation
The chapter explore a complementary climate solution to CO2 reductions: reducing a key group of warming agents knows as super pollutants or short-lived climate pollutants (SLCPs) to bend the warming curve quickly (over a few decades) while we pursue CO2 mitigation to bend the curve in the long term (over several decades to centuries). Combined, these efforts, if enacted by 2020, give us a significant chance (about 90% probability) of keeping warming well below 2°C (aiming for 1.5°C) in this century and beyond. Mitigation of SLCPs, if completed by 2030, can bend the warming curve by up to 0.6°C by 2050 (about 0.4°C from methane mitigation, 0.1°C from black carbon, and 0.1°C from HFCs), cutting the rate of projected warming by about half compared with “business as usual” and reducing the projected sea level rise between 2020 and 2050 by 20%.
The Kigali Amendment to the Montreal Protocol phases down the production and consumption of hydrofluorocarbon greenhouse gases that were once necessary to rapidly phase out ozone-depleting substances but are no longer needed. The Kigali Amendment complements the emission controls of the UNFCCC Kyoto Protocol and contributes to satisfying the “nationally determined contributions” to reduce greenhouse gas emissions pledged under the 2016 Paris Climate Agreement. In 2016, the International Institute of Refrigeration proposed using Life-Cycle Climate Performance metric for air-conditioning systems while summing up carbon-equivalent direct refrigerant emissions, indirect power plant greenhouse gas emissions, and carbon equivalent embodied emissions. This paper describes an Enhanced and Localized Life Cycle Climate Performance metric developed by a team of international experts to reflect real-life air conditioning system operations.
Climate change is an urgent problem requiring urgent solutions. This report lays out urgent and practical solutions that are ready for implementation now, will deliver benefits in the next few critical decades, and places the world on a path to achieving the longterm targets of the Paris Agreement and near-term sustainable development goals. The solutions consist of four building blocks and 3 levers to implement ten scalable solutions described in this report by a team of climate scientists, policy makers, social and behavioral scientists, political scientists, legal experts, diplomats and military experts from around the world.
Over the past half century, California has provided a remarkable example for the world by achieving dramatic reductions in air pollution, while continuing to grow economically. In this report, we propose a set of strategies for combating climate change and growing the economy in California, the nation and the world, while building present-day and intergenerational wealth, and improving the well-being of people and the planet.
This paper explores the question; How Can the U.S. Lead in Paris to Achieve a Climate Agreement We Can Live With?
This policy paper provides a non-technical overview of these issues and sets out policy recommendations as countries and companies prepare for the 21st Session of the Conference of the Parties to the UNFCCC, to be held in Paris in December 2015. in doing so, the paper explains how the ‘short-lived’ versus ‘long-lived’ discussion is not really a technical issue at all, but an expression of inter-generational priorities.
While negotiations continue for a United Nations Framework Convention on Climate Change (UNFCCC) by December 2015 to take effect in 2020, a parallel effort to achieve fast climate mitigation is needed under the Montreal Protocol on Substances that Deplete the Ozone Layer (Montreal Protocol) to slow current impacts and reduce risks of passing tipping points that trigger self-amplifying feedback mechanisms that accelerate warming. Fast reductions of short-lived climate pollutants (SLCPs), including black carbon (BC), methane (CH4), tropospheric ozone (TO3), and hydrofluorocarbons (HFCs), can cut the rate of climate change in half by mid-century and by two thirds in the Arctic. The Montreal Protocol can be used to quickly phase down production and consumption of high global warming potential (GWP) HFCs, which can avoid 0.1 °C of warming by 2050, and 0.5 °C by 2100, while catalyzing improvements in appliance energy efficiency, which will provide further climate change mitigation by reducing energy use and carbon dioxide (CO2) emissions, particularly in fast-growing economies like India and China. The simultaneous global deployment of existing technologies can reduce emissions of BC, CH4, and TO3by enough to avoid an additional 0.5 °C of warming by 2050, while providing immediate benefits for human health, agriculture, and sustainable development. Fast action to reduce the four SLCPs will reduce the risk of setting off irreversible feedback mechanisms and provide urgent optimism and momentum for a successful UN climate treaty in 2015.
A report by the working group commissioned by the Pontifical Academy of Sciences.
Annual greenhouse gases emissions in 2010 were at their highest recorded level in spite of a global recession. The risk is growing that the climate system could pass tipping points that lead to abrupt and irreversible impacts on a continental scale, perhaps within decades. Successfully addressing climate change requires fast and aggressive action to reduce CO2 emissions, which are responsible for up to 55% of radiative forcing since 1750. It also requires fast and aggressive action to reduce emissions of the pollutants causing the other 45% of warming – the non-CO2 climate forcers, including hydrofluorocarbons (HFCs), black carbon, methane, and tropospheric ozone. Along with reducing CO2, reducing emissions of these non- CO2 climate forcers, which in most cases can be done using existing technologies and existing laws and institutions, can cut the rate of global warming in half for several decades and by two-thirds in the Arctic in the next 30 years. In addition, given the profoundly persistent nature of CO2, it is necessary to explore and implement “carbon-negative” strategies to drawdown existing CO2 on a timescale of decades rather than millennia, and ultimately produce a net drawdown of CO2 when sinks exceed sources.
There is growing international interest in mitigating climate change during the early part of this century by reducing emissions of short-lived climate pollutants (SLCPs), in addition to reducing emissions of CO2. The SLCPs include methane (CH4), black carbon aerosols (BC), tropospheric ozone (O3) and hydrofluorocarbons (HFCs). Recent studies have estimated that by mitigating emissions of CH4, BC, and O using available technologies, about 0.5 to 0.6◦C warming can be avoided by mid-21st century. Here we show that avoiding production and use of high-GWP (global warming potential) HFCs by using technologically feasible low-GWP substitutes to meet the increasing global demand can avoid as much as another 0.5◦C warming by the end of the century. This combined mitigation of SLCPs would cut the cumulative warming since 2005 by 50% at 2050 and by 60% at 2100 from the CO2-only mitigation scenarios, significantly reducing the rate of warming and lowering the probability of exceeding the 2◦C warming threshold during this century.
