Cryosphere Impacts of Overshoot

In pathways with no or limited overshoot of 1.5°C, anthropogenic CO2emissions [must] decline by about 45% from 2010 levels by 2030 (median 50%).

IPCC, 2018: Summary for Policymakers

DSC07503small.jpg

Marine ice sheet instability in Antarctica and/or irreversible loss of the Greenland ice sheet

could result in multi-metre rise in sea level over hundreds to thousands of years.

These instabilities could be triggered at around 1.5°C to 2°C of global warming.

 

IPCC, 2018:

Summary for Policymakers

SEA LEVEL RISE FROM ICE SHEETS

DSC02802prosmall.jpg

Mid-latitude glaciers and snow in the Alps, southern Andes/Patagonia,

Iceland, Scandinavia, New Zealand and North American Rockies can survive at 1.5°,

but these glaciers will disappear almost entirely at 2°C, and snow cover decrease.

 

ICCI, 2019: Cryosphere1.5º: Where Urgency and Ambition Meet – Why Cryosphere Dynamics Must Mean 1.5° Pathways for 2020 NDCs

LOSS OF

GLACIERS & SNOW

acid.jpg

The level of ocean acidification due to increasing CO2 concentrations associated with global warming of 1.5°C is projected to amplify the adverse effects of warming, and even further at 2°C, impacting the growth, development, calcification, survival, and thus abundance of a broad range of species, for example, from algae to fish.

 

IPCC, 2018:

Summary for Policymakers

POLAR OCEAN ACIDIFICATION

DSC00436 small.jpg

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.

 

IPCC, 2018:

Summary for Policymakers

LOSS OF SUMMER ARCTIC SEA ICE

permafrost picture small.jpg

High-latitude tundra and boreal forests are particularly at risk. Limiting global warming to 1.5°C rather than 2°C is projected to prevent

the thawing over centuries of 1.5-2.5 million km2 of permafrost.

 

IPCC, 2018:

Summary for Policymakers

 EMISSIONS FROM PERMAFROST