Special report 1.5 ° C global warming

The Special Report 1.5 ° C global warming (SR1.5) is a special report of the IPCC ( Intergovernmental Panel on Climate Change , IPCC) in preparation for the 24th UN Climate Change Conference in Katowice in 2018 , from 3 to 14 December 2018 (COP 24 ). It examines the feasibility, usefulness and consequences of limiting the global warming to a maximum of 1.5 degrees Celsius, as in 2015 to the 2015 UN Climate Change Conference in Paris (COP 21) from 195 countries around the world adopted the Convention of Paris sought. The report, which was approved on October 8, 2018 at the 48th session of the IPCC in Incheon , South Korea , takes into account more than 6000 scientific references and was prepared by 91 authors from forty countries. Studies accepted by scientific journals before May 15, 2018 were taken into account. The official German title is: "1.5 ° C global warming - The IPCC special report on the consequences of global warming by 1.5 ° C compared to pre-industrial levels and the associated global greenhouse gas emission pathways in connection with a strengthening of the global response to the Climate change threats, sustainable development and efforts to eradicate poverty. "

The core result is that the 1.5-degree target is both achievable and affordable and has great advantages over the less ambitious two-degree target , as it minimizes many of the negative consequences of global warming . At the same time, the report emphasizes that the goal can only be achieved if greenhouse gas emissions are reduced very quickly and, in addition, carbon dioxide is removed from the earth's atmosphere on a very large scale. In contrast, the emission pathways aimed at by the states in the framework of the Paris Agreement would lead to global warming of around 3 degrees by 2100. The goal can only be achieved if a much more ambitious climate protection policy is pursued that encompasses all sectors of society. The foreword of the report ends with the sentence: "Every bit of warming counts, every year counts, every decision counts".

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Overview

In the Paris Agreement concluded in 2015, it was agreed to limit global warming to well below two degrees ("two-degree target"); At the same time, efforts should be made to achieve the 1.5 degree target if possible. According to the special report, however, current climate policies are causing temperatures to rise by more than three degrees. This could have dramatic tipping effects that could lead to a greenhouse earth . Without a rapid change of direction with a rapid reduction in greenhouse gas emissions, the earth would warm up by 1.5 degrees by 2040.

"Limiting global warming to 1.5 degrees requires rapid, far-reaching and unprecedented changes in all areas of society," said the IPCC in a statement on the report. The 1.5 degree target can only be achieved if global carbon dioxide emissions are reduced by 45% by 2030 - compared to the base year 2010 - and drop to zero by 2050. At the same time, the report stated that although achieving the 1.5-degree target required higher investment costs than the two-degree target, the 1.5-degree target had major advantages over the two-degree target. By 2050, the share of renewable energies in the global electricity mix must increase to at least 70 to 85%. Fossil energies should practically no longer be used; Coal and natural gas should supply a maximum of 0 to 2% and 8% of the electricity, respectively, and that only in connection with the CO2 capture and storage . Furthermore, it is called to make the lifestyle, especially the diet of the population, more climate-friendly.

The report states that one degree of warming has already been reached, the negative consequences of global warming are already occurring today and that any further warming would further exacerbate climate damage. In addition, the report comes to the conclusion that it is both possible and financially sustainable to limit global warming to 1.5 degrees. Achieving this goal instead of the two-degree goal could prevent the coral reefs from dying completely and at the same time reduce the consequences for the Arctic .

Central statements

The central statements of the report, which consists of five individual chapters and a summary for politicians, are summarized in a three-page PDF document, which is reproduced here in a condensed form.

General understanding of a temperature increase of 1.5 degrees Celsius

• A1: As a result of human activities, there was a temperature increase of around one degree Celsius compared to the pre-industrial period. Maintaining the current warming trend will warm the earth by 1.5 degrees Celsius between 2030 and 2052.
• A2: This warming due to human greenhouse gas emissions will last for millennia and result in additional long-term effects in the climate system, such as B. the rise in sea level and its consequences. The emissions incurred before the report was published will probably not lead to the 1.5 degree threshold being exceeded.
• A3: The risks for ecosystems and human societies will be 1.5 degrees higher than the current temperature level, but lower than with 2 degrees warming. These risks depend on the extent and speed of warming, the respective geography, level of development and vulnerability as well as the selection and implementation of adaptation and climate protection measures.

Projected climate change, consequences and related risks

• B1: Climate models predict robust differences in the regional climate between the current temperature level and 1.5 degrees warming and between 1.5 degrees and 2 degrees warming. Affected here are z. B. the mean temperature as well as the occurrence of heat extremes , heavy precipitation and the probability of droughts and precipitation deficits.
• B2: By the year 2100 the sea level will rise about 0.1 meters less with a warming of 1.5 degrees than with 2 degrees. Sea levels will continue to rise well after 2100, with the height and speed of this rise depending on the chosen climate protection pathways. A small rise in sea level increases the possibility for human and natural systems to adapt.
• B3: On land, the effects on biodiversity and ecosystems, including species loss and species extinction, will be less with a warming of 1.5 degrees than with a warming of 2 degrees. Limiting warming to 1.5 degrees will reduce the negative impact on various ecosystems and enable them to conserve more of their performance for human uses.
• B4: Limiting global warming to 1.5 degrees instead of 2 degrees will reduce the rise in sea temperature and the acidification of the seas and the decrease in oxygen levels. Therefore, limiting warming to 2 degrees will reduce the risks to biodiversity, fisheries and ecosystems as well as the negative consequences for their usability by humans.
• B5: Risks to human health , livelihood , food security , water supply , human security and economic growth due to climate change will increase with a temperature increase to 1.5 degrees and will increase with a further temperature increase to 2 degrees.
• B6: Most adjustment requirements will be less at 1.5 degrees warming than at 2 degrees. There are a large number of adaptation options that can reduce the risks of climate change. However, even at 1.5 degrees warming, there are limits to adaptation for some human systems as well as natural systems. The number and availability of customization options vary by sector.

Emission pathways to limit global warming to 1.5 degrees Celsius

• C1: In modeled emission paths that achieve the 1.5 degree target with little or no temperature overshoot, carbon dioxide emissions must be reduced by around 45% between 2010 and 2030 and fall to net zero by 2050. To achieve the two-degree target, carbon dioxide emissions must fall by 25% in most of the pathways and reach net zero by 2070. Non-carbon dioxide emissions must be greatly reduced for both the 1.5 and the two-degree target.
• C2: Modeled emission paths that achieve the 1.5 degree target with little or no temperature overshoot require rapid and profound redesign of the areas of energy , land use , city, infrastructure (including transport and buildings) and industry. The extent of these changes is without historical example, but not necessarily in terms of the speed of implementation. What is required are deep emissions reductions in all sectors, a broad portfolio of avoidance options and a significant expansion of investment in these options.
• C3: All modeled emission paths that reach the 1.5 degree target with little or no temperature overshoot assume the use of techniques to remove carbon dioxide from the atmosphere, with a total of between 100 and 1000 billion tons of carbon dioxide over the course of the 21st Century should be removed from the atmosphere. These technologies would be used to compensate for residual emissions, and in most cases to reduce the carbon dioxide content of the atmosphere with negative emissions and thus actively reverse a temperature excess of 1.5 degrees. The realization of negative emissions amounting to several hundred billion tons is affected by a large number of feasibility and sustainability restrictions. Substantial short-term emission reductions and measures to save energy and land consumption can reduce the need for carbon dioxide removal to a few hundred billion tons without the need to use bioenergy with carbon dioxide capture and storage (BECCS).

Strengthening the global response to sustainable development and poverty reduction

• D1: Estimates of the emissions development promised by the states under the Paris Agreement would lead to an increase in annual greenhouse gas emissions to 52 to 58 billion tonnes of carbon dioxide equivalent by 2030 . With this development in emissions, global warming could not be limited to 1.5 degrees even if very ambitious emissions reductions were achieved after 2030. Excessive temperatures above 1.5 degrees and dependence on negative emissions on a large scale can only be avoided if global carbon dioxide emissions are reduced well before 2030.
• D2: The avoided consequences of climate change for sustainable development , eradication of poverty and reduction of inequality would be greater if global warming could be limited to 1.5 degrees instead of 2 degrees, if the synergies between climate protection and adaptation were maximized and if the conflicting goals were minimized would.
• D3: If carefully selected, country-specific adaptation options will also have advantages for sustainable development and poverty reduction if the temperature rise is 1.5 degrees, even if there may be conflicting goals.
• D4: Climate protection options that enable global warming to be limited to 1.5 degrees enable both a multitude of synergy effects and conflicting goals for the goals for sustainable development . The number of possible synergy effects exceeds the number of conflicting goals, but the net effect depends on the speed and size of the effects, the type of climate protection chosen and the management of the respective energy transition.
• D5: Limiting the risks of global warming by 1.5 degrees in the context of sustainable development and poverty reduction requires system changes that can be made possible by increasing investment in adaptation and mitigation investments, the use of political instruments, the acceleration of technological innovation and changes in behavior.
• D6: Sustainable development often supports and enables fundamental social and systemic change, which helps limit global warming to 1.5 degrees. Such changes facilitate the pursuit of climate change resilient development pathways that enable ambitious mitigation and adaptation measures combined with poverty reduction and efforts to reduce inequality.
• D7: Strengthening the capacities for climate protection measures by national and subnational actors, civil society, the private sector, indigenous peoples and local communities can support the implementation of ambitious protective measures that make it necessary to limit global warming to 1.5 degrees. International cooperation can help create the conditions for this to be achieved in all countries, for all people and in the context of sustainable development. International cooperation is a crucial factor for developing countries and vulnerable regions.

Comments

The chairman of the Intergovernmental Panel on Climate Change, Hoesung Lee , described the meeting as one of the most important in the history of the IPCC.

Hans-Otto Pörtner , Co-Chair of IPCC Working Group II, said that the current problems with climate protection are “not on the physical or technological side”, but are “clearly on the political, institutional side”. In addition, he said, “[the] next ten years will be decisive in terms of their effects [...] Any further warming, especially above 1.5 degrees, increases the risk of long-lasting or irreversible changes such as the loss of eco- Systems ". According to the report, the 1.5 degree mark could be reached as early as 2030.

“The IPCC reports are so important in climate policy because they deal with politically relevant topics and have proven their scientific independence for thirty years. The balance, reliability and completeness of the statements are guaranteed by detailed procedural rules with a multi-stage assessment process and global expert participation, ”said the head of the German IPCC coordination office Christiane Textor.

Johan Rockström , resilience researcher and one of the directors of the Potsdam Institute for Climate Impact Research , called the report “really important” and said that its scientific robustness shows that the 1.5 degree target is not just a “political concession”. Rather, it reflects the increasing awareness that warming by two degrees is dangerous. Climate change is occurring earlier and faster than expected, and even the current level of one degree warming is painful.

Niklas Höhne, Head of the New Climate Institute and Professor of Climate Protection at Wageningen University, commented on the report as follows: “The report confirms that transformations at this speed have already taken place, only geographically limited, not yet global. Here are a few examples: In just five years, Norway has made electric cars the new standard, with 50 percent of new registrations being electric. Renewable energies are currently so cheap that some governments are even slowing down development. Renewable energies are pushing coal out of markets like India and China , which nobody would have thought possible five years ago. There are even highlights in problem areas such as industry: The first steel production without fossil fuels started operations in Sweden - unthinkable five years ago. One thing is certain: if we give up on our goal and don't even try, we will definitely miss it by a long way. "

Mojib Latif , meteorologist and climate researcher at the Helmholtz Center for Ocean Research Kiel commented as follows: “It is important that you set yourself ambitious goals. Nothing would be worse than surrendering to the climate problem. What is needed is nothing less than a technological revolution: away from fossil fuels and towards renewable energies and that within a few decades. History shows that technology change is possible in such a short time. Examples would be the transition from horse-drawn carts to automobiles or the current transition from fixed-line networks to mobile phones and smartphones. Currently, more investments are being made globally in renewable energies than in conventional energies. Politicians must accelerate this dynamic. "

One of the IPCC lead authors, Debra Roberts, calls the next few years "probably the most important in human history".

Reactions

Switzerland

The International Energy Agency recommends Switzerland u. a. the electric mobility to promote. The Federal Office of Energy wants to take appropriate steps. The Federal Council wants Switzerland to be climate-neutral by 2050 .

See also

• Climate change
• Global warming
• Consequences of global warming

literature

report

• IPCC: Global Warming of 1.5 ° C - an IPCC special report on the impacts of global warming of 1.5 ° C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change , sustainable development, and efforts to eradicate poverty - SR15. In: ipcc.ch. October 5, 2018, accessed October 8, 2018 . 

Summaries

• Key messages of the report (English, PDF) , final version, IPCC website. Accessed December 31, 2019.
• Key statements of the report (German, PDF) , based on the non-final English version of November 14, 2018, German IPCC coordination office, October 2018.
• Kati Mattern, Eric Fee, Thomas Voigt, Juliane Berger, Guido Knoche, Achim Daschkeit, Claudia Kabel, Mathias Bornschein, Natalie Kern: Key messages of the IPCC special report on 1.5 ° C global warming for dissemination to the public . Documentation of the UBA webinar for multipliers from April 5, 2019. Ed .: Federal Environment Agency (Germany) . No. 34/2019 , October 2019 ( Umweltbundesamt.de - more detailed German-language summary).

Web links

• Special report 1.5 ° C global warming - SR1.5 - de-IPCC. In: de-ipcc.de. October 8, 2018, accessed October 9, 2018 . 
• What is the IPCC report on 1.5 degrees warming about? Background from climate research. In: deutsches-klima-konsortium.de. September 26, 2018, accessed October 8, 2018 . 
• Joachim Müller-Jung: "There has never been such a global challenge". In: FAZ.net . Retrieved October 8, 2018 . 
• IPCC SR15 Press Conference Live Oct 8th 2018 on YouTube

Individual evidence

1. ↑ Summary for Policymakers of IPCC Special Report on Global Warming of 1.5ºC approved by governments (PDF)
2. ↑ Special report 1.5 ° C global warming - SR1.5 - de-IPCC. In: de-ipcc.de. October 8, 2018, accessed October 9, 2018 . 
3. ↑ ^{a b} IPCC (Ed.): Global Warming of 1.5 ° C - Headline Statements from the Summary for Policymakers . 2018 ( ipcc.ch [PDF; 303 kB ]).
4. ↑ Intergovernmental Panel on Climate Change: Consequences of climate change more devastating than assumed . In: Intergovernmental Panel on Climate Change: Consequences of climate change more devastating than assumed | National Geographic . October 8, 2018 ( nationalgeographic.de [accessed October 26, 2018]).
5. ↑ Intergovernmental Panel on Climate Change 2018: Foreword . Special report 1.5 ° C global warming. Retrieved December 6, 2019.
6. ↑ ^{a b} German Climate Consortium: IPCC Special Report 1.5 degrees. September 26, 2018, accessed October 8, 2018 . 
7. ↑ Christopher Schrader : "The Most Important Years in History" . In: Spektrum.de , October 8, 2018, accessed October 8, 2018.
8. ↑ Dirk Godder, dpa: Intergovernmental Panel on Climate Change calls for vigorous action for the 1.5 degree target - heise online. In: heise.de. October 8, 2018, accessed October 8, 2018 . 
9. ↑ ^{a b c} We have 12 years to limit climate change catastrophe, warns UN . In: The Guardian , October 8, 2018, accessed October 8, 2018.
10. ↑ IPCC issues dire climate warning, says coal must go to save Great Barrier Reef . In: Australian Broadcasting Corporation , October 8, 2018, accessed October 8, 2018.
11. ↑ Key statements of the report (German, PDF) ( Memento of the original from April 21, 2019 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , German IPCC coordination office, October 2018. 
12. ↑ UN Climate Change on Twitter. In: twitter.com. September 30, 2018, accessed October 8, 2018 . 
13. ↑ Looking for good ideas for climate protection . In: Tagesschau.de , October 8, 2018, accessed October 8, 2018.
14. ↑ ^{a b} Special Report on Climate Change: Climate Council calls for rapid restructuring of the world economy .
15. ↑ Christoph Seidler: Special report of the Intergovernmental Panel on Climate Change: The world is falling apart - the only question is how much. In: Spiegel Online . October 8, 2018, accessed October 8, 2018 . 
16. ↑ ^{a b} Joachim Müller-Jung: “There has never been such a global challenge”. In: FAZ.net . Retrieved October 9, 2018 . 
17. ↑ Tobias Haberkorn: The flood is coming. In: zeit.de. November 4, 2018, accessed December 31, 2019 . 
18. ↑ Call of the Intergovernmental Panel on Climate Change: This is what the special climate report means for Switzerland . In: srf.ch . October 8, 2018, accessed October 8, 2018.
19. ↑ Federal Council wants Switzerland to be climate-neutral by 2050. In: bafu.admin.ch . August 28, 2019, accessed October 2, 2019 .