Twila Moon
National Snow and Ice Data Center
Cooperative Institute for Research cin Environmental Systems
University of Colorado - Boulder
[email protected] - www.changingice.com - @twilamoon
Land Ice: Observations and updates from the front lines
[Image: NASA Earth Observatory]
Land ice reaches pole to pole
Losing ice globally
[ESA, adapted from Zemp et al., Nature, 2019]
Gr. Ice Sheet
2000-2016
-3700 Gt
Ant. Ice Sheet
2000-2016
-1900 Gt
Losing ice globally
[ESA, adapted from Zemp et al., Nature, 2019]
Local to global impacts
Local to global impacts
6 m 60 m
Local to global impacts
7
Combined
Heat
Ice
Rate = 3.2 ± 0.4 mm/year
Increasing by ~0.1 mm/year, each year
[Leuliette, 2018; NOAA Laboratory for Satellite Altimetry]
Sea Level Rise Today (1993-2018)
[modified from Chen et al., Nature Climate Change, 2017]
Greenland
Antarctica
Land H2O storage
Glaciers & ice caps
Ocean heat
Growing influence of land ice (Greenland!)
Forecast for ocean heat and glacier loss
[Kopp et al., Earth’s Future, 2014]
Thermal expansion Glaciers & Ice caps
Relatively well-constrained Narrow potential range
Greenland Antarctica
Wide range of possible contributions
Increased
snowfall dominates
Runaway ice
sheet decline
Forecast for Earth’s ice sheets
[Kopp et al., Earth’s Future, 2014]
Uncertainty: Marine Ice-Cliff Instability
Helheim Glacier,Greenland
An example??
[DeConto and Pollard, Nature, 2016]
[DeConto and Pollard, Nature, 2016]
Uncertainty: Marine Ice-Cliff Instability
Helheim Glacier,Greenland
An example??
[Edwards et al., Nature, 2019]
Uncertainty: Marine Ice-Cliff InstabilityA
nta
rcti
cco
ntr
ibu
tio
n
[Thomas and Bentley, Quarter. Res., 1978; Image: Hanna et al., Nature, 2013]
Uncertainty: Marine Ice Sheet Instability
Uncertainty: Marine Ice Sheet Instability
[Thomas and Bentley, Quarter. Res., 1978; Image: Hanna et al., Nature, 2013]
Uncertainty: Marine Ice Sheet Instability
[Thomas and Bentley, Quarter. Res., 1978; Image: Hanna et al., Nature, 2013]
Uncertainty: Marine Ice Sheet Instability
[Morlighem: BedMachine Antarctica]
Uncertainty: Marine Ice Sheet Instability
[Morlighem: BedMachine Antarctica]
[Figure: Joughin et al., Science, 2014; Additional results - Rignot et al., GRL, 2014]
MISI: Thwaites Glacier
Neighbor in steady state Strong meltMedium melt,
weak ice shelf margins
Sea level rise due to ice lossfrom Greenland Ice Sheetunder RCP8.5, mm/year
[Horton et al., Ann Rev Env Resour, 2018]
mm/year (2006 – 2100)
Sea level rise will not be evenly distributed
Sea level rise due to ice lossfrom Antarcticaunder RCP8.5, mm/year
[Horton et al., Ann Rev Env Resour, 2018]
mm/year (2006 – 2100)
Sea level rise will not be evenly distributed
[Larour et al., Science Advances, 2017]
Local SLR depends on local ice loss
Interest from planners & decision makers
• NSF Coastlines and People initiative
[Image: Times Record online]
Interest from planners & decision makers
• NSF Coastlines and People initiative
• House Subcommittee on the Environment hearing (House Science, Space and Technology Committee subcommittee) - Sea Change: Impacts of Climate Change on Our Oceans and Coasts (Feb. 2019)
[Image: Times Record online]
Interest from planners & decision makers
• NSF Coastlines and People initiative
• House Subcommittee on the Environment hearing (House Science, Space and Technology Committee subcommittee) - Sea Change: Impacts of Climate Change on Our Oceans and Coasts (Feb. 2019)
• National Academies considering activities
[Image: Times Record online]
Interest from planners & decision makers
• NSF Coastlines and People initiative
• House Subcommittee on the Environment hearing (House Science, Space and Technology Committee subcommittee) - Sea Change: Impacts of Climate Change on Our Oceans and Coasts (Feb. 2019)
• National Academies considering activities
• Conferences: SLR, Managed Retreat, Coastal Resilience & Adaptation
[Image: Times Record online]
[Mouginot et al., PNAS, 2019]
[Mouginot et al., PNAS, 2019]
SMB: -1±16 Gt/yrD: -49±9 Gt/yr
1980-1990
[Mouginot et al., PNAS, 2019]
SMB: -1±16 Gt/yrD: -49±9 Gt/yr
1980-1990
SMB: +0±16 Gt/yrD: -40±8 Gt/yr
1990-2000
[Mouginot et al., PNAS, 2019]
SMB: -1±16 Gt/yrD: -49±9 Gt/yr
1980-1990
SMB: +0±16 Gt/yrD: -40±8 Gt/yr
1990-2000
SMB: -98±16 Gt/yrD: -87±8 Gt/yr
2000-2010
[Mouginot et al., PNAS, 2019]
SMB: -1±16 Gt/yrD: -49±9 Gt/yr
1980-1990
SMB: +0±16 Gt/yrD: -40±8 Gt/yr
1990-2000
SMB: -98±16 Gt/yrD: -87±8 Gt/yr
2000-2010
[Mouginot et al., PNAS, 2019]
SMB: -1±16 Gt/yrD: -49±9 Gt/yr
1980-1990
SMB: +0±16 Gt/yrD: -40±8 Gt/yr
1990-2000
SMB: -98±16 Gt/yrD: -87±8 Gt/yr
2000-2010
[Image: Twila Moon]
Important ice-ocean interactions
RCP4.5 without melt coupling
2000 2050 2100
Coupled models change results
[Golledge et al., Nature, 2019]
RCP4.5 without melt coupling with melt coupling
2000 2050 2100 2000 2050 2100
Coupled models change results
[Golledge et al., Nature, 2019]
RCP4.5 without melt coupling with melt coupling
2000 2050 2100 2000 2050 2100RCP8.5
Coupled models change results
[Golledge et al., Nature, 2019]
RCP4.5 without melt coupling with melt coupling
2000 2050 2100 2000 2050 2100RCP8.5
Coupled models change results
[Golledge et al., Nature, 2019]
[Larour et al., Science, 2019]
2000 surface
Bedrock
Coupled models change results
[Larour et al., Science, 2019]
Bedrock
Ocean
2350 surface: Uncoupled
Coupled models change results
[Larour et al., Science, 2019]
Bedrock
Ocean
2350 surface: Coupled
Coupled models change results
[Roberts et al., 2010]
Glacier geoengineering
[Moore et al., Nature comment, 2018]
Glacier geoengineering
…
[Moon et al., Nature correspondence, 2018]
[Moore et al., Nature comment, 2018]
Climate geoengineering
Clark et al. 2016
How much carbon we emit over the next 100 years.
Land ice loss is ~irreversible,with millennial-scale impact
[Clark et al. 2016]
Ice loss is ~irreversible,with millennial-scale impact
Thank you!