Global Warming of 1.5°C

Global Warming of 1.5°C
An IPCC special report on the impacts ofglobal warming of 1.5°C above pre-industrial
levels and related global greenhouse gas
emission pathways, in the context ofstrengthening the global response to thethreat of climate change, sustainabledevelopment, and efforts to eradicate
poverty.

The report in numbers

91 Authors from 40 Countries
133 Contributing authors
6000 Studies

1 113 Reviewers

42 001 Comments

Where are we?
Since pre-industrial times, human activities havecaused approximately 1.0°C of global warming.
• Already seeing consequences for people,
nature and livelihoods• At current rate, would reach 1.5°C between
around 2030 and 2050

• Past emissions alone do not commit theworld to 1.5°C
Ashley Cooper / Aurora Photos

|

Cumulative emissions of CO2 and future non-CO2 radiative forcing
determine the probability of limiting warming to 1.5°C

|Cumulative emissions of CO2 and future non-CO2 radiative forcing
determine the probability of limiting warming to 1.5°C

|Cumulative emissions of CO2 and future non-CO2 radiative forcing
determine the probability of limiting warming to 1.5°C

|Cumulative emissions of CO2 and future non-CO2 radiative forcing
determine the probability of limiting warming to 1.5°C

|Cumulative emissions of CO2 and future non-CO2 radiative forcing
determine the probability of limiting warming to 1.5°C

|Cumulative emissions of CO2 and future non-CO2 radiative forcing
determine the probability of limiting warming to 1.5°C

|Cumulative emissions of CO2 and future non-CO2 radiative forcing
determine the probability of limiting warming to 1.5°C

Faster immediate CO2emission reductions limit
cumulative CO2 emissions

|Cumulative emissions of CO2 and future non-CO2 radiative forcing
determine the probability of limiting warming to 1.5°C

Maximum temperature rise is determined bycumulative net CO2 emissions and net non-CO2
radiative forcing due to methane, nitrous oxide,aerosols and other anthropogenic forcing agents.

Spatial patterns of changes in mean temperature and precipitation
Global warming of 1.5°C

26 CMIP5 models; hatching : 66% model agreement

2°C

DifferenceSpatial patterns of changes in extreme temperature and precipitation
Global warming of 1.5°C
Number of hot days(days)

Temperature ofhottest days (°C)

Temperature ofcoldest nights (°C)

Extremeprecipitation (%)

2°C

Difference

|How do climate-related risks change
as a function of the level of global warming?

Confidence level : M, medium; H, high; VH; very high|

How do climate-related risks for “Reasons For Concern” change
as a function of the level of global warming?

Confidence level : M, medium; H, high; VH; very highAt 1.5°C compared to 2°C• Up to several hundred million fewer people
exposed to climate-related risk andsusceptible to poverty by 2050
• Disproportionately high risk for Arctic,
dryland regions, small island developing
states and least developed countries• Lower risks for health, livelihoods, foodsecurity, water supply, human security andeconomic growth

Jason Florio / Aurora Photos• Wide range of adaptation options which canreduce climate risks; less adaptation needs at
1.5°C

|

What are greenhouse gas emission pathways
compatible with limiting warming to 1.5°C?

https://data.ene.iiasa.ac.at/iamc-1.5c-explorer/18

|What are greenhouse gas emission pathways
compatible with limiting warming to 1.5°C?

Pathways with no or limited overshootPathways with a high overshoot19

|What are greenhouse gas emission pathways
compatible with limiting warming to 1.5°C?

20

Limiting warming to 1.5°C
Would require rapid, far-reaching andunprecedented changes in all systems
A range of technologies and behavioural changes
Scale up in annual investment in low carbon energy
and energy efficiency by factor of five by 2050Renewables supply 70-85% of electricity in 2050
Coal declines steeply, ~zero in electricity by 2050
Deep emissions cuts in transport and buildings
Transitions in land use, scale depending on
mitigation portfolio
Urban and infrastructure system transitions,changes in urban planning practices
Mint Images / Aurora Photos

|Four illustrative model pathways
Fossil fuels and industry
Agriculture, forestry, land use
Billion tons CO2 per year (GtCO2/yr)

Bioenergy with CCSYear

Where are we?

• National pledges are not enough to limit
warming to 1.5°C• Avoiding warming of more than 1.5°C
would require carbon dioxide emissions todecline substantially before 2030

Peter Essick / Aurora Photos

Climate change and sustainability• Ethical and fair transitions• Different pathways have different synergies
and trade-offs with UN Sustainable
Development Goals (SDGs)• Careful mix of measures to adapt to climatechange and reduce emissions can help
achieve SDGs
• Low energy demand, low material
consumption and low carbon food carryhighest benefits• Cooperation,
governance, innovation andmobilisation of finance key for feasibility

Ashley Cooper/ Aurora Photos

ipcc.ch/report/sr15 :Summary for Policy Makers
10 Frequently Asked Questions
5 Chapters
Glossary