1analysis byCLIMATEACTIONTRACKERreviews by2Acknowledgements Preface authorsPotsdam Institute for Climate Impact Research Stefan Rahmstorf and Anders LevermannReport writers Independent Policy Analyst and Writer Chloe Revill and Victoria HarrisAnalytical contributors Carbon Tracker James Leaton Climate Action Tracker Michiel Schaeffer, Andrzej Ancygier, Bill Hare, Niklas Roaming , Paola Parra, Delphine Deryng, Mahlet Melkie, and Claire Fyson Climate Analytics; Niklas Hhne, Sebastian Sterl, and Hanna Fekete New Climate Institute; Yvonne Deng, Kornelis Blok, and Carsten Petersdorff Ecofys, a Navigant companyYale University Angel Hsu, Amy Weinfurter, and Carlin RosengartenSpecial thank you to the additional organizations and individuals who provided or reviewed the analysis for 2020 The Climate Turning Point, either in whole or in part, from the identification of six milestones to guidance on analysis of the milestone targets. Organizations and individuals Climate Policy Initiative CPI, Conservation International CI with a special thank you to Shyla Raghav; International Renewable Energy Agency IRENA, The New Climate Economy NCE, Partnership on Sustainable Low Carbon Transport SLoCaT, Reid Detchon at the UN Foundation, SYSTEMIQ, We Mean Business WMB, and World Resources Institute WRI 3PREFACE WHY GLOBAL EMISSIONS MUST PEAK BY 2020Authored by Stefan Rahmstorf and Anders LevermannPotsdam Institute for Climate Impact ResearchIn the landmark Paris Climate Agreement, the world’s nations have committed to “holding the increase in the global average temperature to well below 2 C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 C above pre-industrial levels”. This goal is deemed necessary to avoid incalculable risks to humanity, and it is feasible – but realistically only if global emissions peak by the year 2020 at the latest. Let us first address the importance of remaining well below 2C of global warming, and as close to 1.5C as possible. The World Meteorological Organization climate report for the past year has highlighted that global temperature and sea levels keep rising, reaching record highs once again in 2016. Global sea ice cover reached a record low, and mountain glaciers and the huge ice sheets in Greenland and Antarctica are on a trajectory of accelerating mass loss. More and more people are suffering from increasing and often unprecedented extreme weather events , both in terms of casualties and financial losses. This is the situation after about 1C global warming since the late 19th Century. Not only will these impacts get progressively worse as warming continues, but our planet also runs a growing risk of crossing critical tipping points where major and largely irreversible changes to the Earthsystem are triggered see Fig. 1.Fig. 1 Tipping elements in the Earth system, in relation to past global temperature evolution since the last Ice Age 20,000 years ago as well as future warming scenarios. The Paris range of 1.5 – 2 C warming is shown in grey; the bars show increasing risk of crossing tipping points from yellow to red.OUR SHARED MISSION FOR 20204The West Antarctic Ice Sheet WAIS in Fig. 1 has likely already been destabilised, committing the world to at least three meters of global sea-level rise in coming centuries – an outcome that scientists have warned about since the 1970s. The Greenland Ice Sheet – holding enough ice to eventually raise global sea levels by seven meters – may likewise be destabilised below 2C. Coral reefs have suffered pan-tropical mass bleaching in 2016 and are doing so again in 2017 as a result of warming oceans, and only if global temperature stays well below 2C some remnants of the world’s coral reefs can be saved. The Gulf Stream system THC in Fig. 1 appears to be already slowing and recent research indicates it is far more unstable than previously thought. Because overall global temperature rise depends on cumulative global CO2 emissions, the Paris temperature range can be translated, with some uncertainty, into a budget of CO2emissions that are still permissible. This is the overall budget for the century and it lies within the range of 150 to 1050 Gt of CO2, based on updated numbers from IPCC. At the current global emission level of 39 GtCO2 per year, the lower limit of this range would be crossed in less than four years and is thus already unachievable without massive application of largely unproven and speculative carbon dioxide removal technologies. Even the CO2 budget corresponding to the mid-point of this uncertainty range, 600 GtCO2, is equivalent to only 15 years of current emissions. Fig. 2 illustrates three scenarios with this budget and different peaking years for global emissions. It makes clear that even if we peak in 2020 reducing emissions to zero within twenty years will be required. By assuming a more optimistic budget of 800 Gt this can be stretched to thirty years, but at a significant risk of exceeding 2C warming.It is still possible therefore to meet the Paris temperature goals if emissions peak by 2020 at the latest, and there are signs to show we are moving in that direction as global CO2 emissions have not increased for the past three years. We will need an enormous amount of action and scaled up ambition to harness the current momentum in order to travel down the decarbonisation curve at the necessary pace; the window to do that is still open . In summary, declining carbon emissions after 2020 is a necessity for meeting the Paris temperature limit of “well below 2 degrees”. Fig. 2 Three illustrative scenarios for spending the same budget of 600 Gt CO2, with emissions peaking in 2016 green, 2020 blue and 2025 red, and an alternative with 800 Gt dashed.1990 2000 2010 2020 2030 2040 2050 2060051015202530354045YearEmissions5REFERENCES 1 World Meteorological Organisation. WMO Statement on the State of the Global Climate in 2016 WMO, Geneva, 2017. 2 World Meteorological Organisation. Weather extremes in a changing climate hindsight on foresight WMO, Geneva, 2011. 3 Schellnhuber, H. J., Rahmstorf, S. Winkelmann, R. Why the right climate target was agreed in Paris. Nature Climate Change 6, 649-653 2016. doi10.1038/nclimate3013 4Feldmann, J. Levermann, A. Collapse of the West Antarctic Ice Sheet after local destabilization of the Amundsen Basin. Proc Natl Acad Sci U S A 112, 14191-6 2015. doi10.1073/pnas.15124821125Mercer, J. West Antarctic ice sheet and CO2 greenhouse effect a threat of disaster. Nature 271, 321-325 1978.6Robinson, A., Calov, R. Ganopolski, A. Multistability and critical thresholds of the Greenland ice sheet. Nature Climate Change 2, 429-432 2012. doi10.1038/nclimate14497Frieler, K. et al. Limiting global warming to 2 degrees C is unlikely to save most coral reefs. Nature Climate Change 3, 165-170 2013. doiDoi 10.1038/Nclimate16748Rahmstorf, S. et al. Exceptional twentieth-century slowdown in Atlantic Ocean overturning circulation. Nature Climate Change 5, 475-480 2015. doi10.1038/nclimate25549Peters, G. How much carbon dioxide can we emit 2017 http//cicero.uio.no/en/posts/climate/how-much-carbon dioxide-can-we-emit.10A Roadmap for Rapid Decarbonization. Science, March 24, 2017 Johan Rockstrm, Owen Gaffney, Joeri Rogelj, Malte Meinshausen, Neboja Nakicenovic, Hans Joachim Schellnhuber http//www.sciencemagazinedigital.orgsciencemagazine/24_march_2017pg33pg336Contents I. IntroductionII. RENEWABLES OUTCOMPETE FOSSIL FUELS AS NEW ELECTRICITY SOURCES WORLDWIDEIII. ZERO EMISSIONS TRANSPORT IS THE PREFERRED OF ALL NEW MOBILITY IN THE WORLD’S MAJOR CITIES AND TRANSPORT ROUTESIV. LARGE-SCALE DEFORESTATION IS REPLACED WITH LARGE-SCALE LAND RESTORATION, AND AGRICULTURE SHIFTS TO EARTH-FRIENDLY PRACTICESV. HEAVY INDUSTRY – INCLUDING IRON STEEL, CEMENT, CHEMICALS AND OIL GAS COMMITS TO BEING PARIS COMPLIANTVI. CITIES AND STATES ARE IMPLEMENTING POLICIES AND REGULATIONS WITH THE AIM TO FULLY DECARBONISE BUILDINGS AND INFRASTRUCTURE BY 2050VII. INVESTMENT IN CLIMATE ACTION IS BEYOND USD 1 TRILLION PER YEAR AND ALL FINANCIAL INSTITUTIONS HAVE A DISCLOSED TRANSITION STRATEGYVIII. Conclusion 78 10 13151618217INTRODUCTIONIn 2015, more than 190 nations and many thousands of non-state actors jointly resolved to safeguard and strengthen the social, environmental and economic fabric of life on our shared planet. Together we committed to manifesting a more prosperous, resilient and equitable world in 2030, and set a 1.5-2C temperature rise limit, which fundamentally underpins this better world. We must now act with great urgency to fulfill our shared commitment. If we are to be successful, greenhouse gas emissions must begin their steady decline by 2020. Bending the curve of emissions any later will all but eliminate our chance to stay within 1.5C and move the 2030 Sustainable Development Goals beyond our reach. Given the stakes, failure is simply not an option. What this moment of history demands of us is not a burden; it is a tremendous opportunity. By rising to the challenge, we can create more resilient, secure and fulfilling livelihoods; enjoy access to cleaner air and water, vital to our health; live in better buildings and more livable cities; spur innovation and improve our resource efficiency, creating new jobs, economic opportunities and growth; and regenerate the extraordinary ecosystems that make our planet rich. The intrinsic value of these benefits extends beyond economic metrics but, by 2050, efforts to slow climate change could make us 19 trillion richer in that sense too. The evidence that a 2020 climate turning point is within our grasp is growing every day. Global CO2 emissions have already plateaued, and are expected to remain flat over the coming years thanks, in no small part, to China’s economic transation, as well as the exponential growth in renewables worldwide. There are many signs that an irreversible direction of travel has been set investment shifts, technology breakthroughs and cost reductions, a deepening understanding of eco-system services, resilient business and government leadership, as well as a staggering upsurge of citizen activism - all indicate that change is inevitable. But when it comes to climate, timing is everything and we need to step-up the pace of change, accelerating a rapid drawdown in global emissions by 2020. Our shared mission now is to drive 6 revolutions, so that by 2020 1. Renewables outcompete fossil fuels as new electricity sources worldwide 2. Zero emissions transport is the preferred of all new mobility in the world’s major cities and transport routes 3. Large-scale deforestation is replaced with large-scale land restoration, and agriculture shifts to earth-friendly practices 4. Heavy industry - including iron steel, cement, chemicals and oil gas - commits to being Paris compliant 5. Cities and states are implementing policies and regulations to fully decarbonize buildings and infrastructure by 2050 6. Investment in climate action is beyond USD 1 trillion per year and all financial institutions have a disclosed transition strategyJust as the Paris Agreement was a deeply shared endeavor, so delivering on its promise must be too Our success in Paris was not an accident; it was the result of us rallying behind a common strategy, and abandoning resignation for a can-do attitude that accepted this challenge as our own. In this next phase, we will need to come together once again. Delivering these 6 revolutions will not be easy, and we will need to support each other along the way to ensure the transition is just and equitable. But just as we delivered success in Paris, so we can deliver the 2020 climate turning point too. This is our moment. This is our great opportunity. 8“We need to bend the global curve of emissions no later than 2020 and reach a fossil-fuel free world economy by 2050. Yes, this is a grand transation. Is it doable Yes. Is it a sacrifice No. The evidence grows day-by-day that a decarbonized world is a more attractive world.”PROF JOHAN ROCKSTRM, DIRECTOR, STOCKHOLM RESILIENCE CENTRE 1. OUR SHARED MISSION FOR 2020 RENEWABLES OUTCOMPETE FOSSIL FUELS AS NEW ELECTRICITY SOURCES WORLDWIDE NECESSARY Replacing fossil fuel powered electricity generation with renewables is key to global emissions peaking by 2020. Already power generation emits 42 of energy-related CO2 2014 and its relevance will only increase as other sectors, like transport, buildings and industry, become electrified. This is true even if accompanied with equally necessary and large improvements in energy efficiency perance. Our electricity supply systems must undergo a radical transation to ensure that global emissions peak in 2020 and move rapidly to zero by 2050. At the same time, this transation can and must enhance energy security and ensure that the billions of citizens worldwide who today lack access to modern energy are not left behind. Decoupling global economic growth from power-related carbon emissions can deliver a new era of prosperity that does not destabilize the climate. To deliver a 2020 climate turning point, our shared mission is to ensure that by then electricity generation from renewables outcompetes production from fossil fuels worldwide. This would see 1. Renewables making up at least 30 of the world’s electricity supply 2. No new coal-fired power plants being built, and all existing coal-fired power plants already in the process of being retiredDESIRABLE Shifting to a clean power system will deliver meaningful benefits in and of itself, as well as limiting our human impact on the climate. Perhaps most importantly, shutting down fossil fuel power plants can reduce the number of early deaths from outdoor air pollution by up to 500,000 globally each year. If polluting residential energy use is replaced with clean electricity, this could reduce the death toll by a further million. There are also significant economic and security related benefits to be reaped. The development of domestic renewable energy sources will allow countries to decrease their energy import dependency, improve their trade balance and reduce their vulnerability to international market volatility. Investing in renewable energy capacity will also create many new jobs, particularly in regions affected by high levels of unemployment, such as rural areas. Finally, the distributed character of renewables, especially if combined with ever cheaper large and small-scale storage options , makes it possible to grant electricity access to people living off the main grid, as well as to the residents of small islands. Improved energy access, in particular access to clean energy, also has health and economic benefits for the most vulnerable communities such as those who curr