Snow, Water, Ice
and Permafrost
in the Arctic
Summary for Policy-makers

This Summary for Policymakers presents key findings
and implications of the second SWIPA assessment,
conducted from 2010 to 2016 and published in 2017.
More than 90 scientists contributed to the assessment,
which was peer-reviewed by 28 experts in a rigorous
quality control process. More details on the SWIPA
process and findings are available in the full SWIPA
report, available at www.amap.no/swipa.
The Snow, Water, Ice and Permafrost in the Arctic(SWIPA) assessment is a periodic update to the Arctic
Climate Impact Assessment, published in 2005 by
the Arctic Monitoring and Assessment Programme(AMAP), the Conservation of Arctic Flora and Fauna(CAFF), and the International Arctic Science Committee(IASC). SWIPA focuses on changes to the Arctic
cryosphere (the portion of Arctic land and water that isseasonally or perennially frozen), and the implicationsof those changes. The first SWIPA assessment
was conducted between 2008 and 2010, and was
published in 2011.

About the Arctic Council
The Arctic Council is the leading intergovernmental
forum promoting cooperation, coordination, andinteraction among the Arctic States, Arctic indigenous
peoples, and other Arctic inhabitants on common
Arctic issues, in particular on issues of environmental
protection and sustainable development in the
Arctic. Established in 1996, the Arctic Council iscomposed of eight Member States (Canada, theKingdom of Denmark, Finland, Iceland, Norway,
the Russian Federation, Sweden, and the UnitedStates). It also includes six organizations representing
Arctic indigenous peoples: the Aleut International
Association, the Arctic Athabaskan Council, Gwich’inCouncil International, the Inuit Circumpolar Council,
the Russian Association of Indigenous Peoples of theNorth, and the Saami Council.

About AMAP
AMAP, established in 1991 under the eight-country
Arctic Environmental Protection Strategy, monitors andassesses the status of the Arctic region with respect topollution and climate change. AMAP produces sciencebased, policy-relevant assessments and public outreachproducts to inform policy and decision-making

2

Photo: Søren Rysgaard

processes. Since 1996, AMAP has served as one of the
Arctic Council’s six working groups.

Key Findings
Key findings of the SWIPA 2017 assessment include:
Arctic’s climate is shifting
1 The
to a new state
Rising concentrations of greenhouse gases are driving
widespread changes in the Arctic’s sensitive climate,hydrological, and ecological systems. Since 2011, downward
trends have continued in sea ice thickness and extent, land
ice volume, and spring snow cover extent and duration,
while near-surface permafrost has continued to warm.
With each additional year of data, it becomes increasingly
clear that the Arctic as we know it is being replaced by awarmer, wetter, and more variable environment. Thistransformation has profound implications for people,
resources, and ecosystems worldwide.
While SWIPA 2017 includes many important new findings,
summarized below, three points in particular deserve
special emphasis:• The Arctic Ocean could be largely free of sea ice in summer
as early as the late 2030s, only two decades from now.
• The recent recognition of additional melt processes
affecting Arctic and Antarctic glaciers, ice caps, andice sheets suggests that low-end projections of global
sea-level rise made by the Intergovernmental Panel on

AMAP Assessment Areachange in the Arctic
2 Climatehas continued at a rapid pace

Climate Change (IPCC) are underestimated.

• Arctic temperatures are rising faster than the global• Changes in the Arctic may be affecting weather

at any time since instrumental records began in aroundaverage. The Arctic was warmer from 2011 to 2015 thanin mid-latitudes, even influencing the Southeast

1900, and has been warming more than twice as rapidly

Asian monsoon.

as the world as a whole for the past 50 years. January
2016 in the Arctic was 5°C warmer than the 1981–2010
average for the region, a full 2°C higher than the previous
record set in 2008, and monthly mean temperatures in
October through December 2016 were 6°C higher than

THE ROLE OF ARCTICGLACIERS AND ICE CAPS IN
GLOBAL SEA-LEVEL RISE
Scientific advances since 2011 show that while
Arctic glaciers and ice caps represent only aquarter of the world’s land ice area, meltwaterfrom these sources accounts for 35% of current
global sea-level rise.

average for these months. Sea temperatures are also
increasing, both near the surface and in deeper water.
• The frequency of some extreme events is changing.
Recent observations include a widespread decline inperiods of extreme cold during both winter and summer,
and increases in extreme warm periods in some areas,such as northern Alaska and northeastern Russia inautumn and spring.
3

Sea ice is becoming more mobile as its extent and

TRADITIONAL AND LOCALKNOWLEDGE

thickness decrease, increasing ice-related hazards.

The SWIPA scientific assessment is based primarilyon peer-reviewed observations, methods, andstudies, which in many cases include contributions
from traditional and local knowledge. However it isrecognized that this approach does not necessarily
capture all relevant knowledge held by Indigenous
and local communities.

compared with observations reported in 2011.

More open water occurs in all months of the year

• The area and duration of snow cover are decreasing.
Snow cover has continued to decline in the Arctic, with
its annual duration decreasing by 2–4 days per decade.
In recent years, June snow area in the North Americanand Eurasian Arctic has typically been about 50% below
values observed before 2000.

• The decline in sea ice continues, with variation fromyear to year. Sea ice thickness in the central Arctic
Ocean declined by 65% over the period 1975–2012.
Sea ice extent has varied widely in recent years, but
continues a long-term downward trend. A record low
minimum sea ice extent occurred in 2012 and a record
low maximum sea ice extent occurred in 2016.
Older ice that has survived multiple summers is rapidly
disappearing; most sea ice in the Arctic is now ‘first year’
ice that grows in the autumn and winter but melts during
the spring and summer.
Except for the coldest northern regions of the Arctic
Ocean, the average number of days with sea ice coverin the Arctic declined at a rate of 10–20 days per decade
over the period 1979–2013, with some areas seeing
much larger declines. Warm winds during the autumn
of 2016 substantially delayed the formation of sea ice.

• Permafrost warming continues. Near-surface
permafrost in the High Arctic and other very cold areas
has warmed by more than 0.5°C since 2007–2009,
and the layer of the ground that thaws in summer has
deepened in most areas where permafrost is monitored.
• The loss of land-based ice has accelerated in recent
decades. Since at least 1972 the Arctic has been thedominant source of global sea-level rise. Seventy percentof the Arctic’s contribution to sea-level rise comes fromGreenland, which on average lost 375 gigatons of ice
per year—equivalent to a block of ice measuring 7.5
kilometers or 4.6 miles on all sides—from 2011 to 2014.
This is close to twice the rate over the period 2003–2008.
• Freshwater storage in the Arctic Ocean has
increased. Compared with the 1980–2000 average, thevolume of freshwater in the upper layer of the Arctic
Ocean has increased by 8,000 cubic kilometers, or morethan 11%. This volume equals the combined annual

Sea level contribution, mm/yr
1.2

1.0
Thermal expansion
0.8

Antarctic land ice
Greenland ice sheet

0.6

Canadian Arctic glaciers
Russian Arctic glaciers

0.4

U.S. Arctic (Alaskan) glaciersGreenland glaciers

0.2

Scandinavian glaciers
Other glaciers04Terrestrial storage

During the period 2004–
2010, melting Arctic land
ice accounted for more than
1/3 of global sea-level rise,
while thermal expansion
caused by warming water
contributed another 1/3
and contributions from
Antarctica, other glaciers andchanges in terrestrial storage
contributed less than 1/3.

discharge of the Amazon and Ganges rivers, and could—• The Arctic Ocean may be ice-free sooner than

if it escapes the confines of the Arctic Ocean—affectexpected. Extrapolations of recent observed data

circulation in the Nordic Seas and the North Atlantic.

suggest a largely ice-free summer ocean by the late

• Ecosystems are changing. The decline in sea ice
thickness and extent, along with changes in the timingof ice melt, are affecting marine ecosystems andbiodiversity; changing the ranges of Arctic species;

2030s, which is earlier than projected by most climate
models. Natural variability and model limitations makeprecise predictions impossible.
• Declines in snow and permafrost will continue.

increasing the occurrence of algal blooms; leading to

The duration of snow cover is projected to decrease by anchanges in diet among marine mammals; and altering

additional 10–20% from current levels over most of the

predator-prey relationships, habitat uses, and migration

Arctic by mid-century under a high emissions scenario,

patterns. Terrestrial ecosystems are feeling the effects ofand the area of near-surface permafrost is projected tochanges in precipitation, snow cover, and the frequency

decrease by around 35% under the same scenario.

or severity of wildfires. The occurrence of rain-on-snow
and winter thaw/refreezing events affects grazing animals
such as caribou, reindeer, and muskox by creating an
ice barrier over lichens and mosses. While many tundra
regions have become greener over the past 30 years,
reflecting an increase in plant growth and productivity,
recent satellite data show shifts toward browning(indicating a decrease in plant cover and productivity)• The melting of land-based ice will contributesignificantly to sea-level rise. If increases ingreenhouse gas concentrations continue at current rates,
the melting of Arctic land-based ice would contribute an
estimated 25 centimeters to sea-level rise between 2006
and 2100. Many of the smallest glaciers across the Arctic
would disappear entirely by mid-century.

over large areas of the Arctic, particularly in Eurasia.

• The Arctic water cycle will intensify. Climate models• Arctic climate trends affect carbon storage andproject increases in cold-season precipitation of 30–50%

emissions. New estimates indicate that Arctic soils holdabout 50% of the world’s soil carbon. While thawing
permafrost is expected to contribute significantly tofuture greenhouse gas emissions, the amount released
over the past 60 years has been relatively small.
• The impacts of Arctic changes reach beyond theArctic. In addition to the Arctic’s role in global sealevel rise and greenhouse gas emissions, the changes
underway appear to be affecting weather patterns
in lower latitudes, even influencing Southeast
Asian monsoons.

3 hanges will continue throughC
at least mid-century, due towarming already locked into
the climate system• Warming trends will continue. Models project that
autumn and winter temperatures in the Arctic will
increase to 4–5°C above late 20th century values before
mid-century, under either a medium or high greenhousegas concentration scenario. This is twice the increaseover the Arctic Ocean toward the end of this century,with an increasing portion of that precipitation fallingas rain instead of snow.
• Arctic ecosystems will face significant stresses anddisruptions. Changes in sea ice are expected to affectpopulations of polar bears, ice-dependent species ofseals and, in some areas, walrus, which rely on sea ice
for survival and reproduction. There will also be losses of
ice-associated algae. Physical disturbance arising froman increasing frequency of wildfire and abrupt thawingof permafrost could accelerate ecological shifts, suchas the expansion of tall shrubs and trees into tundra.
Boreal forests will be affected by thawing permafrost,
increases in wildfires, insect pest outbreaks, and climatezone shifts.
• Arctic changes will affect sources and sinks
of important greenhouse gases. The amount of
atmospheric carbon dioxide absorbed by the Arctic
Ocean may be significantly affected by changes in
sea-ice cover, the structure and functioning of marine
ecosystems, and the hydrological cycle. Thawing
permafrost is expected to increase emissions of methane.

projected for the Northern Hemisphere. These increases
are locked into the climate system by past emissions
and ocean heat storage, and would still occur even if theworld were to make drastic near-term cuts in emissions.
5

4

 ubstantial cuts in global
S
greenhouse gas
emissions now canstabilize impacts after
mid-century

5

 daptation policies canA
reduce vulnerabilities• Adaptation at the community andregional levels, both in the Arctic
and globally, is essential. The near

• Reducing concentrations of greenhouseinevitability of accelerating impacts in thegases in the atmosphere will make a

Arctic and globally between now and mid-difference. While the changes underway

century reinforces the urgent need for local

in the Arctic are expected to continue

and regional adaptation strategies that canthrough at least mid-century, substantial

reduce vulnerabilities and take advantage

global reductions in net greenhouse gasof opportunities to build resilience.

emissions can begin to stabilize sometrends (albeit at higher levels than today)
after that. Reversing trends would require
reductions in atmospheric greenhousegas concentrations.
• Compliance with the Paris Agreement
will stabilize snow and permafrost
losses, but there will still be much lesssnow and permafrost than today. Climate
models show that reducing greenhouse gas
emissions and stabilizing concentrations,
under a scenario roughly consistent with
the Paris Agreement, could stabilize thefurther loss of snow cover and permafrost
after mid-century. In contrast, higher
emissions would result in continued losses.
• Efforts to control greenhouse gas
emissions can have a major impact on
sea-level rise after mid-century. For
example, a scenario roughly consistent
with the Paris Agreement would reduce
end-of-century sea-level rise by 43%
compared with that projected to occur

ffective mitigation and6 Eadaptation
policies
require a solid
understanding of Arctic
climate change• Reducing knowledge gaps will improve
our ability to respond to current andfuture changes in the Arctic. Efforts areneeded to increase the geographic coverageof observations, improve local-levelprojections, and reduce uncertainties.
• Coordination across monitoring efforts,
modeling studies, and international
assessments can facilitate informationsharing and avoid duplication of effort.
As international attention becomesincreasingly focused on Arctic climatechange and its impacts, the need tocoordinate among assessment processes
and studies becomes greater.

under a business-as-usual emissions
scenario.
• However, the Arctic will not returnto previous conditions this century
under the scenarios considered in the
Arctic will be a substantially different
environment from that of today, and by theend of this century Arctic warming may
exceed thresholds for the stability of sea
ice, the Greenland ice sheet, and possibly
boreal forests.

6

Photo: © outdoorsman / Shutterstock

SWIPA 2017 assessment. The near-future

7The Arctic Transformed
The Arctic is still a cold place, but it is warming faster than any other region on
Earth. Over the past 50 years, the Arctic’s temperature has risen by more than
twice the global average. Increasing concentrations of greenhouse gases in theatmosphere are the primary underlying cause: the heat trapped by greenhousegases triggers a cascade of feedbacks that collectively amplify Arctic warming.
As a result, the Arctic of today is different in many

affecting the Arctic’s role as a regulator of global

respects from the Arctic of the past century, or even thetemperature and its influence on Northern Hemisphere

Arctic of 20 years ago. Many of the changes underway

weather, its contribution to sea-level rise, the livelihoods

are due to a simple fact: ice, snow, and frozen ground—of those who live and work in the Arctic, and the habitats

the components of the Arctic cryosphere—are sensitiveof Arctic species. Today’s Arctic is a new environment,

to heat. As the cryosphere changes, so do the Arctic’s

evolving rapidly and in unexpected ways.

physical, chemical, and biological systems, with complex
consequences within and beyond the region.

Despite the many changes already underway or projected,
some of which appear irreversible (such as thawing

Since 2011, evidence for the Arctic’s evolution toward a new

permafrost and melting of the Greenland ice sheet),state has grown stronger. Additional years of data show

climate models show that a scenario roughly equivalent tocontinued or accelerating trends in record warm temperatures,that under the 2015 Paris Agreement of the United Nations

changes in sea ice and snow, melting of glaciers and ice sheets,

Framework Convention on Climate Change would slow

freshening and warming of the Arctic Ocean, thawing ofor stop some trends, especially after the middle of thispermafrost, and widespread ecological changes.

century, with the Arctic’s average temperature stabilizing

Beyond the trends, new data also show stronger evidence
for fundamental shifts in some elements of the cryosphere,
the ocean, and ecosystems. Sea ice in the Arctic is enteringa new regime in which vast areas of ocean that used to becovered by ice throughout the year are now seasonallyice-free and dominated by younger, thinner ice. The
composition of many boreal forests is changing: coniferous
trees are increasingly being replaced by deciduous species
normally found farther south.
Together, these findings portray a system whose
component parts are changing at different speeds,

at a new, higher level. These findings offer encouragement
for the long term, although the Arctic environment willcontinue to undergo significant changes far into the future,requiring northern countries, communities, and operatorsin the Arctic to focus on adaptation.

The Importance of Feedbacks
A number of feedback mechanisms, some of them uniqueto the Arctic, are responsible for the more rapid warming
observed over the Arctic compared with the rest of theworld. These feedbacks amplify warming well beyond theeffects caused by increasing greenhouse gas concentrations
alone. By analyzing climate models, scientists haveidentified the relative contribution of the different

WATER IN THE ARCTIC
While liquid water and water vapor might seem
irrelevant in a region where so much water is frozen,water in all its forms plays key roles in Arctic processes
and ocean systems. For example, the increase in
freshwater flow to the ocean from rivers and melting
glaciers has implications for ocean circulation andclimate that extend far beyond the Arctic.
8

feedbacks to warming in the Arctic.
The largest feedbacks, according to climate models, arerelated to the Arctic’s inefficiency at radiating heat. Coldregions radiate heat slowly, so the warmth trapped bygreenhouse gases tends to build up. Furthermore, warmingin the Arctic is concentrated close to the Earth’s surface,slowing the rate at which heat is lost to space from the topof the atmosphere.

The next-largest warming feedback comes from changes inrivers account for roughly 10% of the world’s total riversurface reflectivity due to the melting of snow and ice. As

discharge, pouring enormous quantities of freshwater,reflective surfaces are replaced by darker surfaces such as

sediment, nutrients, and organic carbon into the Arctic

open water or land, less energy is radiated back to space andOcean every year. Non-Arctic rivers, such as the St.

the region warms further, leading to still more melting. Water

Lawrence River in Canada, also contribute freshwater thatvapor (a powerful greenhouse gas) also provides a warming

ends up in the Arctic. Increases in freshwater flow into the

feedback. Warmer temperatures increase evaporation, and aocean affect ocean circulation, ocean acidification (seewarmer atmosphere can hold more water vapor.

AMAP’s 2013 report on Arctic Ocean acidification), andFollow the Water: The Changing
Interactions between the Cryosphereand the Hydrosphere

biological productivity, and affect weather patterns far tothe south. Melting sea ice also contributes to freshening of
the ocean’s surface. As the sea ice thins and shrinks it also
becomes more mobile, creating hazards to shipping and

The amplifiers of warming described above have contributed

other activities, while increasing the risk that currents will

to an intensified water cycle in the Arctic, in which flows ofpush it to warmer waters where it will melt.

freshwater between the land, the atmosphere, and the ocean
are increasing. This pattern has important implications forhuman populations and ecosystems in the Arctic, as well as
weather at lower latitudes.

Following the path of water through the hydrologicalcycle reveals many complex interactions between waterand the cryosphere, some of which are illustrated in the
figure below.

For example, when precipitation increases in a warmer
climate, much of that water ends up in rivers. As does the
meltwater from snow, glaciers, and ice caps. The Arctic’s

Key Interactions Between Cryosphere and Hydrosphere
Melting glaciers, ice sheets,
and ice caps pour freshwaterand nutrients into the ocean

Thawing permafrost
leads to more warming
through emissions ofmethane and CO2

Arctic changes influence
mid-latitude weather

Evaporation and precipitation
increase with warming
Melting sea ice leads to more open water,
more freshwater in the upper ocean,more evaporation, and more warming

Freshwater and nutrient runoff into the ocean
affect marine ecosystems and ocean circulation

Warm water flows into the Arctic Ocean
from the North Atlantic

Cold water exits the Arctic Ocean
as warm water takes its place

Key interactions between thecryosphere and hydrosphere.
9The Decades Ahead
With the warming alreadycommitted in the climate
system plus the additional
warming expected from risingconcentrations of greenhousegases in the atmosphere, theArctic will experience significant
changes during this century even
if greenhouse gas emissions arestabilized globally at a level lower
to increase, future changes in
the Arctic would be even more
substantial and long-lasting.
Climate models, using scenariosthat depict plausible changes infuture greenhouse gas emissions
and concentrations over time, offer
the following updated projections
for the Arctic in SWIPA 2017:

Photo: ©JoannaPe / Shutterstock

than today’s. If emissions continue

THE PARIS AGREEMENT
AND ARCTIC CHANGE
Efforts to reduce emissions can have an impact in
the later years of this century. Projections suggestthat reducing greenhouse gas emissions undera scenario roughly similar to that under the Paris
Agreement would have the following effects by theend of this century:• Stabilize temperature at 5–9°C above the 1986–
2005 average over the Arctic Ocean in winter.
• Reduce global sea-level rise from 2006–2100 by
more than 20 centimeters.
• Stabilize the duration of snow cover at about 10%
below current values.
• Stabilize near-surface permafrost extent atroughly 45% below current values.
While the Paris Agreement, if implemented, would
limit the extent to which the Arctic climate changes,
the Arctic environment in 2100 would still be
substantially different from that of today.

Temperature
Autumn and winter temperatures will increase by a regional
average of 4°C over the next 30 years—twice the warming
projected for the Northern Hemisphere as a whole—with
new record temperatures observed in some regions andyears. The strongest warming is projected to occur during
the cold season, including spring and autumn for northernEurasia. Even several years of cold weather due to naturalvariations are unlikely to affect the long-term trend, andefforts to reduce greenhouse gas emissions will not affectprojected temperatures until the latter half of this century.
The warming climate will increase the amount of freshwaterin the Arctic, with important implications for people,
industries, ecosystems, and infrastructure.

Sea Ice
The Arctic is expected to be largely free of sea ice in latesummer within the next few decades, possibly as early as the2030s, although natural variability and other factors make it
impossible to make precise predictions. The ice that appears
in winter will be thinner, more salty, less rigid, and moremobile than today’s sea ice. More open water is expected in
winter, affecting temperature and the exchange of moisture10

TodayWarming atmosphere

Melting ice sheets and ice caps

Melting glaciers

Shrinking extent of snow cover andshortening length of snow season
Thawing permafrost

Changing vegetation and ecosystems

Increased risk of coastal erosion
Increasing flow of freshwater andnutrient runoff into the ocean

Thinning, shrinking extent of sea ice

Changing ecosystems

Warming ocean

Key physical changes
underway in the Arctic

Warmer and more humid air, shifting wind patterns

Smaller glaciers,
ice caps, andice sheets

Mid-Century

More methane emissions
from thawing permafrost

Less snow cover, shorter snow season

Warmer, wetter environment
with more rain
Reduced extent
of near-surface
permafrost
Warmer and fresher ocean,changes in ocean circulation
Very little sea ice in warmer months

Key projected changes in
the Arctic at mid-century

SCENARIOS AND PROJECTIONSClimate models project future
conditions, based on scenarios. What
does that mean?
Scenarios depict a range ofplausible alternative futures, basedon assumptions about future
economic, social, technological, andenvironmental conditions that drive
greenhouse gas emissions and theirconcentrations in the atmosphere.

Climate modelers use these scenarios
to project, rather than predict,future climate under each scenario.
Projections answer the question: if
emissions and concentrations wereto proceed along this pathway, whatchanges in climate would result?
SWIPA 2017 compared the outcomesof two different greenhouse gas
concentration scenarios, RCP-4.5

and RCP-8.5. In the RCP-4.5 scenario,
reductions in emissions lead tostabilization of greenhouse gas
concentrations in the atmosphere by2100 and a stabilized end-of-century
global average temperature rise of
1.7–3.1°C above pre-industrial levels.
RCP-8.5 is a high-emission business-asusual scenario, leading to a global nonstabilized temperature rise of 3.8–6°C
by 2100.

11

between the atmosphere and ocean,will contribute 19–25 centimeters toleading to more extreme weather

global sea-level rise by the year 2100.

locally and at lower latitudes. Sea ice
is currently thinning and shrinking
more rapidly than projected bymost models.

Snow and Permafrost
Projected changes in snow coverand maximum accumulation vary
widely over the Arctic. Warmer
coastal areas such as those in
Alaska and Scandinavia will see thefastest and largest declines. The
cold high latitudes of the Arctic
will experience an increase in theannual accumulation of snow. The
largest reductions in snow coverare projected in the spring in mostregions of the Arctic.
The area of near-surface permafrost
in the Northern Hemisphere is
projected to decline by 20% relative
to today’s area by 2040, and could
be reduced by as much as two-thirds
by 2080 under a scenario of highgreenhouse gas emissions. Impacts
will vary widely at regional and local
scales, but local effects are difficult
to project given the lack of fine-scaledetail in models.

Land-based Ice
and Sea Level
The loss of land ice is expected toaccelerate after the middle of thiscentury. New projections of glacierchanges since 2011 provide moreregional detail, showing for example
that some glaciers in northeastern
Russia, Siberia, and the Kamchatka
Peninsula could completely
disappear by mid-century.
Global sea-level rise is expected toaccelerate, although uncertainties
about the Greenland ice sheet’s
response to ongoing warming
hamper scientists’ ability to project
the rate and magnitude of theincrease. A recent analysis developed
for SWIPA estimates that the Arctic
12

The SWIPA analysis estimates thatwhen all sources of sea-level rise areconsidered (not just those from the
Arctic), the rise in global sea level by
2100 would be at least 52 cm for agreenhouse gas reduction scenario
and 74 cm for a business-as-usual
scenario. These estimates are almost
double the minimum estimates

Ecosystems
The rate and magnitude of changes
projected for the Arctic will pushsome species out of their ranges,
while other species may colonize
new areas. For example, many
species depend on sea ice forsurvival and reproduction andtheir populations may declinewith changes in sea ice thickness
and extent (as well as changes inmade by the IPCC in 2013.

the timing of ice formation andAfter the Greenland ice sheet, thepopulations of non-native species

largest Arctic contributions to sea-

may increase due to the warmer

level rise will come from glaciers inwaters and reductions in sea ice.

the Canadian Arctic, Alaska, and theMore frequent wildfires and abrupt

Russian Arctic, along with glaciers

thawing of permafrost could

surrounding the Greenland ice sheet.

accelerate ecological shifts, such

Freshwater

as the spread of tall shrubs and

The Arctic water cycle is expectedmelt), while phytoplankton andtrees into tundra.

to continue to intensify during thisCarbon Cycling

century. Mean precipitation and daily

Reductions in sea ice and otherprecipitation extremes will increasechanges may affect the amountover mid- and high latitudes, withof carbon dioxide absorbed by

implications for the management of

the Arctic Ocean, while thawing

water resources, flow of freshwaterpermafrost is expected to increase

into the Arctic Ocean, changes in sea

emissions of methane. However,

ice temperature, and amplification ofprojections of future impacts

regional warming (through reducedon Arctic sources and sinks ofsurface reflectivity caused by agreenhouse gases are still hamperedshift from snow to more rain in theby data and knowledge gaps.

warmer seasons).
Photo: Knud Falk

Photo: © Nordroden / Shutterstock

What Are the Implications?
Changes underway in the Arctic have wide-ranging consequences for Arctic
ecosystems and people living and working in the Arctic. The Arctic also plays animportant role in global climate and weather, sea-level rise, and world commerce,
which means that impacts in the Arctic resonate far south of the Arctic Circle. A recent
economic analysis of the global costs of Arctic change estimated the cumulative costat USD $7–90 trillion over the period 2010–2100.
The implications of most findings inover much of the ocean since the late

SWIPA 2017 are not fundamentally

1970s, creating more opportunities

different from those reported in 2011,

for marine shipping, commercial

but are supported by more evidence andfisheries, tourism, and access toin some cases warrant greater concern

resources.

due to more significant impacts or new
knowledge. A major new finding is that
Arctic changes may influence weather
far to the south (see text box on page 17
under Global Implications).

Challenges andOpportunities in the Arctic
The rapid changes underway in the
Arctic affect lives, livelihoods, andecosystems throughout the region,
with both positive and negative
consequences.

Access and Transportation• The Arctic Ocean’s open water season
has already increased by 1–3 months• In contrast, losses and decreases
in the thickness of lake and river
ice and changes in permafrost
conditions affect or threaten ice
roads, restricting access to remotecommunities.
• Some northern communities havefound it harder to obtain wild
sources of food due to the shorter
snow cover season (which affects
travel to hunting grounds as wellas animal habitat). The thinningof sea ice and the lengthening
melt season also affect accessto resources.

ADAPTING TO MULTIPLE
DRIVERS OF CHANGE
Climate change is only one ofmany factors contributing tochange in the Arctic. Oil andgas activities, mining, tourism,shipping, fisheries, economic
development, and pollutants are
just some of the other stressors
faced by the Arctic today.
Many of these factors interact
with each other.
To better understand theinterrelationships among
multiple drivers of change
in the Arctic, and to help
decision-makers plan integrated
adaptation strategies, AMAP
is preparing an assessment
on Adaptation Actions for a
Changing Arctic, published in2017.

Risks and Hazards to Arctic Communities• Reductions in coastal (landfast) sea ice, combined withloss of land-based ice and permafrost, are leading tocoastal erosion and flooding, affecting safety and in somecases the very existence of coastal communities.
• The increased mobility of sea ice, as well as the increased
export of land ice into the ocean, lead to an increase inmarine ice hazards.
• Future climate change may bring higher risks ofare higher now than at any point in the last 10,000 years,
based on paleoecological reconstructions of fire history in
the region.
• Communities and infrastructure built on frozen soils are
significantly affected by thawing permafrost, one of themost economically costly impacts of climate change in the
Arctic. The bearing capacity of building foundations has
declined by 40–50% in some Siberian settlements sincethe 1960s, and the vast Bovanenkovo gas field in western
Siberia has seen a recent increase in landslides related

avalanches and floods from rapid melting in some regions

to thawing permafrost. Thawing permafrost may alsoof the Arctic. In 2015, above-average precipitation andcontaminate freshwater resources when previously frozen

record spring warmth in north-central Alaska led toindustrial and municipal waste is released.

extensive flooding that closed the Dalton Highway—the
only road to Alaska’s North Slope oil fields—for 3 weeks,leading to an estimated USD $15 million in damages.
• Warmer and drier conditions have contributed to an• Climate change presents risks to food and water
security through changes in access to hunting areas
and the distribution range of traditional food sources,
contamination of drinking water supplies (including

increase in severe wildfires in the Arctic areas of Northby harmful algal species), changes in traditional foodAmerica and Eurasia. For example, the severity andpreservation techniques, and potential increases infrequency of fires in the taiga forests of interior Alaska

food contaminants.

14

THE ARCTIC’S ROLE IN THE
GLOBAL CLIMATE SYSTEM
Compared with mid-latitudes and thetropics, the Arctic receives relatively little
energy from the Sun. Because most of the
Arctic’s surface is covered in snow and ice,much of the energy that it does receive
is reflected back to space. These factors
account for the Arctic’s cold climate.
The Arctic acts as a global refrigerator by
drawing warm ocean water from the south,
cooling it, and ultimately sinking it toward
the ocean bottom. Surface water moves into replace the sinking water, creating ocean
currents. This movement of warmer ocean
waters to the north has a major influence on
climate; it accounts for northern Europe’s
relatively mild climate compared with that of
Canadian provinces at the same latitude, forexample, and it keeps the tropics cooler thanthey would be otherwise.
Meltwater from Arctic glaciers, ice caps,
and the Greenland ice sheet also influences
climate by flooding the ocean withfreshwater, affecting ocean circulation andweather patterns.
Photo: Søren Rysgaard

Impacts on Wildlife and Ecosystems• Reductions in snow cover change the availability of habitat

The Arctic is both a source and sinkfor greenhouse gases. Changes in thequantities of greenhouse gases such ascarbon dioxide and methane stored orreleased in the Arctic can have a long-term
impact on global climate.

for microorganisms, plants, animals, and birds.
• Winter thaws and rain-on-snow events can damage
vegetation, while refreezing creates a layer of ice over thevegetation that may be difficult for animals to penetratewith their hooves, adversely affecting conditions for
grazing animals such as caribou, reindeer, and musk ox.
• The thinning and loss of sea ice has many impacts
on Arctic life, from promoting the growth of marine
phytoplankton and creating more habitat for openwater species to loss of ice-associated algal species anddisrupting the feeding platforms and life cycles of seals,
polar bears and, in some areas, walrus.
• Food webs are affected by changes in the structure of
ecological communities and shifts in the geographic
ranges of species.

15

Implications for Key Industries

Global Implications• Increases in precipitation could make the Arctic a

Changes in the Arctic affect the rest of the world, notpotential future source of freshwater and hydropower

only in obvious ways (such as the Arctic’s contribution tofor southern areas.

sea-level rise), but through the Arctic’s role in the global• Climate change may facilitate access to oil, minerals,
and other resources, although market forces may playa larger role than climate change in those industries’

climate system, its influence on ocean circulation, and its
impacts on mid-latitude weather.
• Coastal communities, low-lying islands, and ecosystems

activities in the Arctic. Extraction of oil and gas will leadthroughout the world will be affected by the melting of

to more greenhouse gas emissions, exacerbating theland ice (glaciers and ice sheets) in the Arctic, which

impacts described here.

is projected to increase the rate of global sea-level rise.

• Commercial fisheries may also be affected by climatechange, in both positive and negative ways, due tochanges in phytoplankton growth, changes in ocean

Impacts include coastal flooding, erosion, damage tobuildings and infrastructure, changes in ecosystems, andcontamination of drinking water sources.

temperature, northward shifts in the ranges of some

• The implications mentioned above for shipping; accessfish species (e.g., the recent migration of mackerel

to oil, gas, and minerals; and impacts to fisheries haveinto waters around Svalbard and Greenland), andeconomic consequences outside the Arctic.

acidification of the ocean by carbon dioxide.

• Changes in Arctic sea ice cover, marine ecosystems,
and the water cycle affect the amount of carbon dioxidethat the Arctic Ocean absorbs from the atmosphere. The
ocean becomes more acidic as it absorbs more carbon
dioxide, with potential implications for marine life.
Changes in snow cover and permafrost also affect carbon
and nitrogen cycling, as well as methane emissions.

16

ARCTIC CHANGES AFFECT
MID-LATITUDE WEATHEROne of the major new areas of research since2011 is on connections between Arctic changes
and mid-latitude weather. Some studies havelinked the loss of land and sea ice, along withchanges in snow cover, to changes in Northern
Hemisphere storm tracks, floods, and winterweather patterns, and have even found evidence
that Arctic changes influence the onset andrainfall of Southeast Asian monsoons.
While it is clear that Arctic changes can influence
weather outside of the region, scientists are stillworking to characterize the nature, magnitude,and extent of the effects.

Increasing the coverage of observations, in space and time,
will help fill some of these gaps. Remotely sensed datafrom satellites, balloons, ships, aircraft, and underwater
instruments have greatly improved our capability tomonitor change in the Arctic, although the data have
Photo: © B&C Alexander / ArcticPhoto

Improving Our Understanding
The authors of SWIPA 2017 identified a number of areas
where addressing data gaps and improving understandingof key processes would aid efforts to characterize thechanges underway and to project changes in the future.
Two overarching needs identified in the SWIPA 2017 report

limitations in terms of resolution and applicability, andstill need to be verified with on-site observations.
Some important needs relate to the difficulty of providing
useful climate model projections at the local scale. The
lack of local-level projections can impede efforts to develop
adaptation strategies—especially in the case of permafrost,where impacts are influenced strongly by local topography
and hydrology.

include 1) improving predictions for the timing of future

The reliability of future projections will be improved

Arctic changes (which requires a better understandingby reducing uncertainties related to factors such as theof feedbacks in the Arctic cryosphere); and 2) improving

sensitivity of the Greenland ice sheet to climate change

confidence in predictions of interactions between theand the impacts of freshwater inflows on ocean processes.

Arctic and global systems.

Other modeling-related challenges include capturing the

The report also identifies many more specific data gaps andresearch needs. For example, detailed data on permafrost arelacking from important areas, such as the High Arctic regionsof Canada and Russia. Gaps in our understanding of otherfactors, such as the storage and drainage of glacial meltwater,
storage and export of continental freshwater and resulting
effects on marine processes, the role of snow in the evolution

effects of natural climate variability, which can obscuretrends, and resolving differences across models’ projectedchanges past mid-century. Despite these concerns, it isimportant to note that projections for the next several
decades differ little across models or scenarios, andmodels do a generally good job of recreating past andcurrent trends.

of sea ice, interactions between snow and vegetation, andconnections between Arctic changes and weather at lower
latitudes, hamper efforts to model future impacts of warmingin the Arctic. Data gaps also impede predictions of how Arctic
ecosystems will respond to climate change, making it difficult
to identify specific regions of the Arctic that may be mostvulnerable to ecosystem shifts in the future.

17

Recommended Action Steps
The key findings of SWIPA 2017 have implications for policy
and planning in four broad areas:
Limit Future Change

Adapt to Near-Term Impacts

Stabilizing Arctic warming and its associated impacts will

The transformative changes underway in the Arctic will

require substantial near-term cuts in net global greenhouse

continue and in some cases accelerate until at least mid-gas emissions. Full implementation of the Paris Agreement

century regardless of efforts to reduce emissions. Impacts

under the United Nations Framework Convention on

from climate change are thus expected to intensify for at

Climate Change (UNFCCC) will cause Arctic temperatures

least the next three to four decades, creating a clear andto stabilize—at a higher level than today—in the latterurgent need for knowledge and strategies to help Arctic

half of this century. This will require much larger cuts

communities and global society adapt to new conditionsin global greenhouse gas emissions than those planned

and reduce vulnerabilities to expected impacts. Addressing

under current nationally determined contributions to themajor knowledge gaps will help ensure adaptation

fulfillment of the UNFCCC.

strategies are grounded in a solid understanding ofpotential impacts and interactions.

The Arctic states, permanent participants,
and observers to the Arctic Council
should individually and collectively lead
global efforts for an early, ambitious, andfull implementation of the Paris COP21
Agreement, including efforts to reduce
emissions of short-lived climate forcers.

18

The Arctic Council and other internationalorganizations should prioritize researchand knowledge-building efforts leading toenhanced certainty in predictions of changes
and their consequences at local to global
scales, facilitating the development ofeffective adaptation responses to changes
in the Arctic cryosphere.

Support the Advancementof Understanding

Raise Public Awareness of the Implicationsof Changes in the Arctic Cryosphere

SWIPA 2017 demonstrates great advances in our

Outreach and public sharing of information about Arctic

understanding of changes in the Arctic cryosphere, butclimate change, its consequences, uncertainties, risks,

also reveals major knowledge gaps. It also identifies several

adaptation options, and effects of emission reductions areunmet scientific goals and specific areas where more

key to informed governance and policy development.

observations and research are needed. As awareness ofArctic climate change and its consequences has grown,
a number of international organizations, such as theIntergovernmental Panel on Climate Change (IPCC), theWorld Meteorological Organization (WMO), and theInternational Council for Science (ICSU) through theInternational Arctic Science Committee (IASC), have become

The Arctic Council, permanent participants,
and observers to the Council should prioritize
informing and educating the public about
observations, projections, and implicationsof Arctic climate change.

increasingly engaged in understanding the implications ofArctic change. Making advances in these areas will requireinternational coordination; long-term commitments tofunding; the application of traditional and local knowledge;
engagement with stakeholders; and coordinated andenhanced observation networks.

The Arctic Council should continue its efforts
to monitor, assess, and understand Arctic
climate change and its implications. It should
also support and interact with efforts ofinternational organizations and conventions
such as IPCC, WMO, the UNFCCC, and theConvention on Long-Range Transboundary
Air Pollution (CLRTAP) to promote theinclusion of Arctic perspectives in their work.

Photo: Søren Rysgaard
19

Snow, Water, Ice
and Permafrost
in the Arctic
Summary for Policy-makers

This document presents the AMAP 2017 Snow, Water,
Ice and Permafrost in the Arctic (SWIPA) Assessment
Summary for Policy-makers. More detailed informationon the results of the assessment can be found in
the SWIPA Scientific Assessment Report. For more
information, contact the AMAP Secretariat.

AMAP Secretariat
Gaustadalléen 21
N-0349 Oslo
NorwayTel. +47 21 08 04 80
Fax +47 21 08 04 85
amap@amap.no
www.amap.no

Front Cover: © W. Lynch / ArcticPhotoThis document was prepared by the Arctic Monitoring and Assessment
Programme (AMAP) and does not necessarily represent the views of
the Arctic Council, its members or its observers.