IPCC Report on Global Warming of 1.5 °C October 2018

image Published: Nov 28, 2018

The United Nations Inter Governmental Panel on Climate Change  (IPCC)  published a special report in October 2018 on the impacts of global warming of 1.5 °C.  The report examines those risks that could be avoided by containing global warming to 1.5 °C and what action would be necessary to achieve this.   

Why is this important?

The report restates the message presented in previous IPCC reports to the United Nations: that climate change is happening; that it is anthropocentric (we are causing it) and that it has serious consequences not only for us but for other species and habitats.  What it also makes clear is that the  difference  between a temperature increase of 1.5°C  and 2°C leads to significant additional risks. While it is still theoretically  possible to contain warming to 1.5°C  the report sets out that this will require urgent changes in all sectors of the economy.  However commitments made by national governments to date are likely to result in warming of closer to 3 degrees.

The response in Scotland

The Scottish Parliament is currently considering a Bill to introduce new targets to reduce the emission of greenhouse gases.  The Scottish Government is proposing a target reduction of 90% by 2050 whereas  campaigners are calling for a net zero carbon emissions by 2050.  The publication of the IPCC report has added to demands for a zero emissions target  and the Scottish Government has indicated that it will consider this new evidence in relation to the Bill.

What can we do?

Government must set a lead but churches and congregations concerned about climate change can show leadership locally.   Eco Congregation Scotland provides the best opportunity for congregations to face up to this challenge in three ways.

Spiritual living: Making the link between climate change and the Christian faith

Practical living: Taking practical action in the church and in the home to reduce our contribution to climate change

Global living: becoming involved in advocacy locally or in the wider world on climate change.

Many congregations are already active but the new report  reinforces just how serious climate change  is becoming. This challenges eco-congregations  and denominations to consider new actions. This is a subject both the Church of Scotland and ECS must now revisit.

Below are extracts from the IPCC  Report on Global Warming of 1.5 °C or you can read it in full here:  http://www.ipcc.ch/report/sr15/

Why 1.5 Celsius?

Human activities have caused approximately 1.0°C of global warming above pre-industrial levels and global warming is likely to reach 1.5°C between 2030 and 2052 if it continues to increase at the current rate.  Climate-related risks exist  for global warming of 1.5°C  but are they are lower than warming of 2°C  The risks depend on the magnitude and rate of warming, geographic location, levels of development and vulnerability, and on the choices and implementation of adaptation and mitigation options

Projected Climate Change, Potential Impacts and Associated Risks

There are many projected impacts of global warming.  These include increases in:

mean temperature in most land and ocean regions

extreme heat in most inhabited regions

heavy precipitation in several regions

the probability of drought and precipitation deficits in some regions

Rainfall and Drought

Risks from droughts and precipitation are likely to be higher at 2°C compared to 1.5°C with risks, in particular heavy precipitation associated with tropical cyclones is projected to be higher at 2°C and the area of land affected by flood will be larger.

Sea Level Rise

Sea level is rising and will continue to rise well beyond 2100, the magnitude and rate of this rise depending on future emissions.  A slower rate of sea level rise enables greater opportunities for adaptation in small islands, low-lying coastal areas and deltas


Of 105,000 species studied, 9% of insects, 8% of plants and 4% of vertebrates are projected to lose over half of their climatically determined geographic range for global warming of 1.5°C, compared with 18% of insects, 16% of plants and 8% of vertebrates for global warming of 2°C. Impacts associated with other risks such as forest fires, and the spread of invasive species, are lower at 1.5°C compared to 2°C of global warming

Tundra and boreal forests are particularly at risk of degradation and loss.  Limiting global warming to 1.5°C rather than 2°C is projected to prevent the thawing over centuries of a permafrost area in the range of 1.5 to 2.5 million km2

Sea warming and loss of coral reefs

The probability of a sea-ice-free Arctic Ocean during summer is substantially lower at global warming of 1.5°C when compared to 2°C.  With 1.5°C of global warming, one sea ice-free Arctic summer is projected per century. This likelihood is increased to at least one per decade with 2°C global warming.  

Coral reefs are projected to decline by a further 70–90% at 1.5°C with larger losses (>99%) at 2ºC. The risk of irreversible loss of many marine and coastal ecosystems increases with global warming, especially at 2°C or more.

Human impacts

Regions at disproportionately higher risk include the Arctic, dryland regions, small-island developing states, and least developed countries. Poverty and disadvantages are expected to increase in some populations as global warming increases; limiting global warming to 1.5°C, compared with 2°C, could reduce the number of people both exposed to climate-related risks and susceptible to poverty by up to several hundred million by 2050. Limiting warming to 1.5°C, compared with 2ºC, is projected to result in smaller net reductions in yields of maize, rice, wheat, and potentially other cereal crops, particularly in sub-Saharan Africa, Southeast Asia, and Central and South America.

Action to limit global warming

Limiting global warming requires limiting the emissions of CO2 to stay within a total carbon budget.  As noted above global warming is likely to reach 1.5°C between 2030 and 2052.  Therefore to stay within 1.5°C will require rapid and far-reaching transitions in the economy: in energy use, land management and farming, urban development and infrastructure (including transport and buildings), and in industry.  These transitions imply deep emissions reductions in all sectors, a wide portfolio of mitigation options and a significant upscaling of investment.

Impact on poverty and sustainable development goals

The climate change impacts on sustainable development, eradication of poverty and reducing inequalities would be greater if global warming were  2°C rather than  1.5°C.  Climate change impacts and responses are closely linked to sustainable development which balances social well-being, economic prosperity and environmental protection. The United Nations Sustainable Development Goals (SDGs), adopted in 2015, provide a framework for assessing the links between global warming and development goals.

Adrian Shaw, Climate Change Officer

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