All people on Earth depend directly or indirectly on the ocean and cryosphere Significance of SROCC: covering 84 per cent of Earth surface (71o, 10 gl, 3pf), following the water from the highest mountains to the deepest ocean, from the equator to both poles and back. Polar regions vast share: 20% of the global ocean surface area, 90% of the world’s continuous and discontinuous permafrost area, 69% of the world’s glacier area including both of the world’s ice sheets, almost all of the world’s sea ice, and land areas with the most persistent winter snow cover.
Top level themes: Raise the ambition Make nature part of the solution Put people at the centre
Global-scale cryosphere losses are projected to continue in the near-term. The rates and magnitudes of these cryospheric changes are projected to increase further in the second half of the 21st century in a high greenhouse gas emissions scenario.The Greenland and Antarctic Ice Sheets are projected to lose mass at an increasing rate throughout the 21st century and beyond. Strong reductions in greenhouse gas emissions in the coming decades are projected to reduce further changes after 2050. The more ambitiously and earlier we act, the more able we will be to address unavoidable changes, manage risks, improve our lives and achieve sustainability for ecosystems and people around the world – today and in the future.
Arctic sea ice has thinned and contracted for all months of the year; contemporaneous increase in ocean temperature. September sea ice reductions are 12.8 ± 2.3% per decade. This is likely unprecedented for at least 1000 years. Significant impact on albedo and climate; potential impacts on mid-latitude weather.
Sea ice loss is projected to continue, with differences after 2050 strongly dependent on the magnitude of warming. For global warming of 1.5°C, the annual probability of a sea ice free September by the end of century is around 1%. This rises to 10–35% for global warming of 2°C. Future ocean warming is projected, and depends strongly on future greenhouse gas emissions.
The area corrosive to organisms that form shells and skeletons using calcium carbonate minerals expanded between the 1990s and 2010. This will continue in future - but the area impacted will be drastically different depending on CO2 levels in the atmosphere. (Areas with surface waters undersaturated in calcium carbonate mineral aragonite year-round in 2100)
Projected climate change impacts (RCP8.6) on Arctic marine ecosystems: Increases and decrease of productivity and populations, Shifts in abundance and distribution of plant and animal species, Increases in disturbance from diseases. Traditional fishing / hunting places inaccessible. Income, livelihoods, food security, well-being, and cultural values of communities negatively impacted. Costs and benefits unequally distributed: People with the highest exposure and vulnerability are often those with the lowest capacity to respond. Limited knowledge, financial resources, human capital and organisational capacity are constraining adaptation in many human sectors in the Arctic.
Arctic surface air temperature has increased by more than double the global average over the last two decades. Arctic June snow cover extent on land declined by more than 13% per decade from 1967 to 2018, a total loss of approximately 2.5 million km2. Permafrost temperatures have increased to record high levels since observations started in the 1980s.
Between a quarter and half of current tundra region is projected to be lost by 2050 over expansion of woody shrubs and trees. Projections indicate a loss of globally unique high-Arctic biodiversity. About 20% of Arctic land permafrost is vulnerable to abrupt permafrost thaw and ground subsidence, with local to landscape scale impacts on water in soils, lakes and rivers, for ecosystem productivity and disturbances (wildfires and disease outbreaks), and ecosystem services. The majority of Arctic infrastructure is located in regions where permafrost thaw is projected to intensify by mid-century. Permafrost thaw-induced subsidence of the land surface is projected to impact overlying urban and rural communication and transportation infrastructure in the Arctic. These impacts are projected to deeply and negatively impact people’s livelihoods.
Widespread permafrost thaw is projected for this century and beyond with the potential of adding more greenhouse gases to the atmosphere. With global warming limited to well below 2°C, around one quarter of near-surface permafrost will thaw by 2100. If emissions continue to increase strongly, around 70% near-surface permafrost could be lost. A high emission scenario leads to the cumulative release of tens to hundreds of billions of tons (GtC) of permafrost carbon to the atmosphere by 2100 with the potential to exacerbate climate change (average across models 92 ± 17 GtC). Lower emissions scenarios dampen the response of carbon emissions. Methane contributes a small fraction of the total additional carbon release but is significant because of its higher warming potential. The CO2equivalents /radiative forcing /proportion of CO2 vs CH4 of these carbon emissions is not well understood, but estimates point at CH4 to contribute 40-70 percent of the total forcing from permafrost C emissions this century. Increased plant growth is projected to replenish soil carbon in part, but will not match carbon releases over the long term For context, total annual anthropogenic CO2 emissions were 10.8 ± 0.8 GtC yr–1 (39.6 ± 2.9 GtCO2 yr–1) on average over the period 2008–2017. Total annual anthropogenic methane emissions were 0.35 ± 0.01 GtCH4 yr–1, on average over the period 2003–2012.
Atmospheric GHG reduction a prerequisite for constraining unavoidable risks: - global: climate feedbacks from permafrost thaw and high and sustained rates of sea level rise from polar ice sheets melt Regional: - ecosystem-based adaptation and opportunities for climate-resilient development are limited to low degrees of warming Some Arctic cultures and biodiversity may be lost under high emission scenarios
Place people, their wellbeing, and regional action in the center of timely and ambitious responses Participation and integrating local and indigenous knowledge in decision making implies transformation of many existing institutions Adaptive fisheries management that regularly evaluates and updates measures, informed by assessments of future ecosystem trends: within-season, annual, and long-term long-term harvest adjustments based on precautionary principle. There are limits to the managements of these impacts with available response mechanisms under rapid ecosystem change
All people on Earth depend directly or indirectly on the ocean and cryosphere
Trend: IPCC finds more pronounced, more urgent, more action-oriented language …on the basis of ever-increasing clarity of the science.
Significance of SROCC: covering more than 90 per cent of Earth surface, following the water from the highest mountains to the deepest ocean, from the equator to both poles an back.
Our Changing Polar Regions
Our Changing Polar Regions
- Some Context for COP25
IPCC Special Report on
the Ocean and Cryosphere in a Changing Climate (SROCC)
Martin Sommerkorn, WWF Arctic Programme
Coordinating Lead Author, IPCC SROCC Polar Regions
Synopsis Polar Regions
I. The polar regions are losing ice, and their
oceans are changing rapidly, with regional and
II. The polar regions of the future will appear
profoundly different, dependent on the degree of
III. Choices are available that limit impacts and build
resilience, but their efficacy needs to be enabled.
Transition to unprecedented polar oceans environments
but more negative than positive.
Arctic and sea ice associated
species are loosing habitat
Income, livelihoods, food
security, well-being, and cultural
values deeply negatively
Some economic sectors benefit,
but also create new risks
Impacts on Arctic marine biodiversity, ecosystems, human systems, and people
Impacts on Arctic land biodiversity, ecosystems, human systems, and people
permafrost thaw and
hydrology is causing
Infrastructure at risk
24-52% of tundra projected
to be lost by 2050
Income, livelihoods, food
security, well-being, and
cultural values deeply and
Permafrost carbon potential to exacerbate global warming
High emission scenario:
cumulative release of tens to
hundreds of GtC of permafrost
carbon by 2100
Methane fraction not well
Increased plant growth is
projected to replenish some soil
carbon but not to match carbon
releases over the long term.
Pathways to Polar Region Resilience
Urgent, ambitious, and sustained emissions reductions
Strengthening multiscale linkages of governance arrangements across sectors,
jurisdictions, and timeframes
Supporting effective responses through investing in capacity building and linking
multiple forms of knowledge with decision making in adaptive governance
Cautious and highly adaptive management along trajectories of projected
change applying the ecosystem approach and preparing for surprises
Establishing networks of protected areas to strengthen biodiversity resilience
and ecosystem adaptation
Our ocean and cryosphere –
They sustain us.
They are under pressure.
Their changes affect all our lives.
The time for action is now.