Why 1.5ºC Matters: Key Messages from the New IPCC Report on Climate Change

Globally, coral reefs are projected to decline by 99% in a 2ºC global warming scenario and 79-90% in a 1.5ºC warming scenario. Photo of coral reef from NOAA photo library.

By Jeffrey Qi | 7 October 2018 | Vancouver, BC

Key Messages

  • Anthropogenic climate change is worsening and to avoid total climate disaster the global community must limit global warming to 1.5ºC.
  • To achieve the 1.5ºC pathway, a 45% decrease in global net anthropogenic CO2 emissions from 2010 level by 2030, reaching net zero around 2050, is needed.
  • The current NDC commitments made by parties to the Paris Agreement will not meet the emission reductions needed to limit global warming to 1.5ºC, even if ambition increases after 2030.
  • Climate change will impact global biodiversity and ecosystem integrity and human health, livelihoods, food security, water supply, human security, and economic growth.
  • Sufficient emissions reductions require rapid and far-reaching transitions in energy, land, urban, transportation, buildings, infrastructure, and industrial systems; it also implies system transitions that require the increase of adaptation and mitigation investments, policy instruments, the acceleration of technological innovation, and behaviour changes.
  • Local knowledge and Indigenous Traditional Ecological Knowledge (TEK) and their political acceptability are important to societal-wide behavioural changes.
  • Climate mitigation under a 1.5ºC pathway will have both positive and negative consequences on the SDGs.
  • International cooperation and strengthening capacity for climate action are urgently needed to limit global warming.

On October 8th, 2018, the Intergovernmental Panel on Climate Change (IPCC) published its Special Report (SR15) on the impacts of 1.5ºC of global warming and global greenhouse gas emission pathways. The meeting took place in Incheon, South Korea, with five days of meetings and negotiations between IPCC Working Groups I, II, and III, and governmental focal points.

IPCC is the international body for “assessing the scientific basis of climate change, its impacts and future risks, and options for adaptation and mitigation.” The panel consists of hundreds of leading scientists who review existing modalities and research papers to assess global climate change every 6 years. Their assessment reports (AR) and summary for policy-makers provide vital information that help decision-makers develop climate policies and inform the global community about the state of anthropogenic climate change.

In 2015, Parties of the UN Framework Convention on Climate Change invited the IPCC to author the SR15 report. The SR15 report will feed into the Talanoa Dialogue at COP 24 in Katowice, Poland. The report will support the Parties to the Paris Agreement to take stock of the current progress towards the long-term goals of the Paris Agreement and gather inputs for developing their own Nationally Determined Contributions, or NDCs.

Anthropogenic climate change is worsening

The SR15 authors, through reviewing scientific research around the world, found with high confidence that anthropogenic activities have caused approximately 1ºC of global mean temperature warming above pre-industrial levels. We are likely to see a 1.5ºC warming between 2030 and 2052 if we continue to emit greenhouse gases (GHGs) in a “business as usual” fashion. SR15 suggests with high confidence that most land regions will experience an increase in hot days, even in those regions that are not typically warm.

The SR15 climate models project hot extremes in most inhabited regions, heavy precipitation and drought in some regions, and rapid change in the mean temperature in most land and ocean regions. Notably, extreme hot days in mid-latitudes will likely warm up to 3-4ºC higher with global warming of 1.5ºC and 2ºC, and extreme cold area in high-latitudes region will experience mean temperature warming up to 6.5ºC in a 2ºC global warming scenario.

Figure 1: Observed global temperature change and modeled responses to stylized anthropogenic emissions and forcing pathways

Global sea-level rise endangers the livelihoods of small islands, low-lying coastal areas and deltas

A 1.5ºC global warming pathway would lead to a 0.26-0.77 m in global sea-level rise by 2100, endangering the lives and livelihoods of many people who live on small islands, low-lying coastal areas and deltas around the world. It also concerns the survival of some states and heavily-populated areas. This can be attributed to the marine ice-sheet instability in Antarctica and the irreversible loss of the Greenland ice sheet that would result in multi-metre sea-level rise if we continue the ‘business as usual’ emissions pathway. There is a chance that an ice-free Arctic Ocean in summer will happen once every 10 years in a 2ºC warmed future, or once every century if the climate pathway can be kept at 1.5ºC.

BC is facing the threat of sea-level rise that would impact the agricultural industry, coastal populated regions, and risking seawater intrusion into rivers and waterways. In an ongoing BCCIC study on municipal climate action, almost all of the local government officials and experts interviewed mentioned sea-level rise as one of the biggest climate impacts BC faces. Local governments are working with their provincial and federal counterparts to build resilience and adapt to a rising sea-level.

Biodiversity is endangered

SR15 projects that out of the 105,000 species on land studied, 6% of insects, 8% of plants and 4% of vertebrates will lose their climatically determined geographic range in a 1.5ºC climate pathway – and the figure doubles for a pathway of 2ºC. Tundra and boreal forests, which covers the majority of Canada’s northern region, are particularly at risk of climate change-induced degradation and loss, with woody shrubs encroaching into the tundra ecosystem. In regards to marine ecosystems, rising ocean temperature will exacerbate increases in ocean acidity and decreases in ocean oxygen levels, posing the risk of irreversible loss of many marine and coastal ecosystems.

Limiting global warming to 1.5ºC will avert more severe climate disasters

Policy-makers around the world must aim to limit global warming to 1.5ºC (compared to 2ºC) as laid out as the long-term goal of the Paris Agreement. Limiting global warming to 1.5ºC instead of 2ºC will reduce increases in atmospheric and ocean temperatures, as well as avoid a 10 cm increase in global sea-level. It will reduce risks to biodiversity, fisheries, ecosystems, as well as risks to human health, livelihoods, food security, water supply, human security, and economic growth. A 1.5ºC pathway will also decrease the likelihood of an ice-free Arctic Ocean in summer from once every 10 years to once a century, and avoid the catastrophic loss of coral reefs (99% decline in a 2ºC scenario and 79-90% decline in a 1.5ºC scenario).

Reduction in anthropogenic CO2 emissions is urgently needed

SR15 indicates that to achieve the 1.5ºC pathway a 45% decrease in global net anthropogenic CO2 emissions from 2010 level by 2030, reaching net zero around 2050, is needed. For a 2ºC pathway, emissions need to decline by about 20% by 2030 and reach net zero by 2080. SR15 also projects that the current NDCs under the Paris Agreement will not limit global warming to 1.5ºC, even if ambition increases after 2030.

Dramatic reduction requires rapid and far-reaching transitions in energy, land, urban, transportation, buildings, infrastructure, and industrial systems. In the context of sustainable development and poverty eradication, it implies system transitions that require the increase of adaptation and mitigation investments, policy instruments, the acceleration of technological innovation, and behaviour changes. Global model pathways project that the annual average investment needed in the energy system is around 2.4 trillion USD (at 2010 level) between 2016 and 2035 representing about 2.5% of the world GDP.

Figure 2: Global emissions pathway characteristics (from IPCC SR15 SPM)

Local and Indigenous knowledge is important for limiting global warming

SR15 recognizes that education, information, community capacity-building, local knowledge, and Indigenous traditional ecological knowledge (TEK) can accelerate behavioural changes. Policy acceptability of local and Indigenous knowledge systems is urgently needed for enabling the implementation of policies and measures that would lead to a 1.5ºC pathway.

Climate mitigation has both positive and negative effects on the SDGs

Sustainable development often enables fundamental societal and system transitions required, however climate mitigation has both synergy and trade-offs on the Sustainable Development Goals (SDGs). There are robust synergies for SDG 3 (health), 7 (clean and renewable energy), 11 (sustainable cities and communities), 12 (responsible consumption and production), and 14 (life below water). There are also potential trade-offs with SDG 1 (poverty), 2 (hunger), 6 (water), and 7 (energy access), if not carefully managed.

Capacity-building and international cooperation are urgently needed to limit global warming

“Strengthening the capacities for climate action of national and sub-national authorities, civil society, the private sector, indigenous peoples and local communities can support the implementation of ambitious actions implied by limiting global warming to 1.5°C.”

“International cooperation can provide an enabling environment for this to be achieved in all countries and for all people, in the context of sustainable development. International cooperation is a critical enabler for developing countries and vulnerable regions.”

Partnership should involve non-state actors, both public and private, like financial institutions, civil society, and scientific institutions and academia. Strengthening the capacity of non-state actors is crucial for coordinated sectoral and cross-sectoral policy implementation.

Above is a synthesized summary of the major messages to policy-makers by the IPCC. Anthropogenic climate change poses a risk to our common future and the survival of many species which constitute the biodiversity and the integrity of the ecosystems that make up this beautiful, living planet. The special report causes concerns to the extent and the magnitude of the problem we are facing. The global community must act together and limit global warming through collective action. It is worth noting that the IPCC recognizes the 1.5ºC pathway as the preferred projection for the future, while a net zero-degree Celsius increase in global mean surface temperature should be the ultimate goal we strive to achieve.

There is a long way to go for countries to achieve the 45% emission reduction by 2030. Parties to the Paris Agreement must increase their commitments for climate mitigation and raise their ambitions towards climate action. Climate change concerns health, livelihoods, social development, economic growth, and the survival of some members of the global community. By recognizing it as a cross-cutting issue it would, hopefully, spark the political will needed to implement emissions reduction and sustainable development policies that will contribute to the 1.5ºC pathway needed to avoid global climate disaster.

Facts about SR15

The 1.5ºC Special Report of the IPCC was authored by 91 scientists from 44 citizenships and 40 countries of residence with 14 coordinating lead authors, 60 lead authors, and 17 review editors. There are 133 contributing authors with over 6,000 cited references. A total of 42,001 expert and government review comments were received by the IPCC prior to the publication of the report (12,895 for the 1st Draft, 25,476 for the 2nd Draft, and 3,630 for the Final Government Draft).

In addition to SR15, the IPCC will release two other reports: 1) Special Report on the Ocean and Cryosphere in a Changing Climate and 2) Special Report on Climate Change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems. The IPCC will also release its Sixth Assessment Report (AR6) in 2022, feeding into the first global stocktake under the Paris Agreement in 2023.


Works Cited:

See the IPCC SR15 report here: www.ipcc.ch/report/sr15/
See IPCC Factsheet: http://ipcc.ch/news_and_events/docs/factsheets/FS_what_ipcc.pdf
See the SR15 Summary for Policy-Makers: http://templatelab.com/ipcc-special-report-1.5/
See IPCC media release on SR15: https://www.ipcc.ch/2018/06/14/media-reports-on-draft-ipcc-special-report-on-global-warming-of-1-5-oc/ 


Jeffrey Qi is a policy intern with BCCIC and a technical NGO observer with the BCCIC Youth Delegation to UNFCCC, a member of YOUNGO. He is an undergraduate student majoring in political science and environmental studies at the University of British Columbia.

The BCCIC Youth Delegation is a member of YOUNGO, the children and youth constituency of the UNFCCC. The delegation is administered by the BC Council for International Cooperation (BCCIC), a member of Climate Action Network Canada (CAN-Rac).