Gino Casassa

Conferencias sobre Cambio Climático, 21 agosto 2009Hotel Dreams, Temuco

Nuevas evidencias sobre el cambio climático y eventuales consecuencias para Chile

Gino Casassa

Centro de Estudios Científicos Valdivia, Chile

EFECTO INVERNADERO

VENUS: T = 462°C CO2 level = 96.5% P = 92 EarthMARS: T = -20 to -140°C CO2 level = 95.7% P = 0.007 Earth

IPCC, 2007

Rates of change for the three greenhouse gases, N2O, CH4, CO2 and their combined radiative forcing for the last 22 ka

Joos F., Spahni R. PNAS 2008;105:1425-1430

©2008 by National Academy of Sciences

IPCC, 2007

2005 relative to 1750

IPCC; 2007

GCMs

IPCC

IPCC AR4

IPCC AR4

DGF UCh – CONAMA, 2007PRECIS (Providing Regional Climates for Impact Studies),UK Met Office 25 km resolution

MESOSCALE MODELS

IPCC AR4

Clausius-Clapeyron

Water content in a warmer atmosphere

IPCC AR4

IPCC Technical Paper “Climate Change and Water”, 2008

FIG. 8. Linear trends from 1948 to 2004 in annual (water year) (a) discharge from each 48 lat 3 58 lon coastal box estimated from available gauge records and reconstructed river flow, (b) the runoff trend inferred from the discharge trend shown in (a), (c) observed surface air temperature and (d) precipitation (from Qian et al. 2006), and (e) CLM3- simulated snow cover and soil ice water. DAI et al., 2009, J.Climate.

“World’s major rivers drying up”

IPCC Technical Paper “Climate Change and Water”, 2008

Values represent the median of 12 climate models using the SRES A1B scenario.

Milly et al., Policy Forum, Science, 2008

Policy Forum, Science, 319, 573-574, 2008

COLAPSO DEL PRINCIPIO ESTATICO ¡DEBEMOS CONSIDERAR CAMBIO CLIMATICO!

EVENTOS CLIMATICOS EXTREMOS

IPCC AR4 WGI

Extreme weather events

IPCC AR4 WGII

2008/2009: verano más cálido desde 1915

La temperatura máxima alcanzó este verano pasado 30.6°C, como promedio de la estación de verano. El valor medio histórico es de 28.9°C, es decir, representa un calentamiento del aire 1.7°C mayor que el valor medio histórico. La zona centro-sur, entre Curicó y Temuco, también se caracterizó por presentar unos de los veranos más cálidos en los últimas 5 décadas. Los promedios de la temperatura máxima fueron 30.7°C en Curicó, 29.7°C en Chillán y 26.1°C en Temuco, representado así una anomalía térmica que superó en casi 2°C el promedio histórico. DMC, 2009

2003 SUMMER HEAT WAVE IN EUROPE

IPCC, 2007

IPCC AR4

IPCC AR4

IMPACTOS FISICOS

Observational evidence from all continents and most oceans shows that many natural systems are being affected by regional climate changes, particularly temperature increases.

Global assessment of data since 1970 has shown it is likely that anthropogenic warming has had a discernible influence on many physical and biological systems.

CRIOSFERA

Temperate ice (T=@ melting point)

vs.

Cold ice

(T< melting point)

IPCC, 2001

GLIMSWGMSNSIDC

Antarctica: 13,586,400 km2; Greenland 1,736,095 km2; Canadian Arctic islands: 151,057 km2; Central Asia: 114,800 km2; North America 76,880 km2; South America 29,347 km2 (Chile 75%) ; Europe: 5,759 km2; Africa: 10 km2

30 AÑOS

10 METERS

NATIONAL GEOGRAPHYC

O’Higgins Glacier, Patagonia

(Casassa, 2008)

Muir Glacier, Alaska

(NSIDC/WDC, 2006)

1945

2005

1941

2004

Lake Cachet 2, NPIApril 2008October 2008December 2008March 2009

Lake Témpanos, SPIApril-May 2007

GLACIAL LAKE OUTBURST FLOODS (GLOFs)= JÖKULHLAUPS

GLACIAR CHACALTAYA, BOLIVIA

Pouyaud et al., 2005, HSJ

WATER RESOURCESJob 6:15 … las corrientes impetuosasJob 6:16 que bajan turbias por el deshielo y mezcladas con la nieve,Job 6:17 que al tiempo del calor se secan, y al calentarse desaparecen en su cauce

EOS, Vergara et al., 2007

Warming 'opens Northwest Passage' The most direct shipping route from Europe to Asia is fully clear of ice for the first time since records began.14 Sep 2007

Meier et al., 2008

Greenland: 7.3 m SLE

Steffen et al.

Univ. Colorado

Greenland moulin

Jakobshavn Glacier

Dietrich et al., 2007

Retreat: 30 km in 150 yThinning: 60 m/yIce flow: 45 m/y

13.5 million km2 (10% of the Earth) - 98% covered by ice70% of the Earth´s fresh water - 91% of the ice on EarthStores 55 m of sea level - 2000 m average ice thickness>4500 m ice at some places - Ice velocities 10-2500 m/a

Antarctica,the seventh continent...

NASA/SVS

The Antarctic Ice Sheet

• 56.6 m sea level equivalent (SLE)• Temperatures well below freezing• West Antarctic ice sheet (5 m SLE) rests on a soft bed that is

below sea level• Inherently unstable?

Antarctica without ice

“The Weak Underbelly”

EastWest

Source: R. Bindschadler, NASA/GSFC

NASA – Waleed Abdalati

Warming on the Antarctic PeninsulaFaraday/Vernadsky

ICE SHELF COLLAPSES,

31 January 2002

LANSAT

NSIDC

ICE SHELF COLLAPSES,

17 February 2002

http://nsidc.org/iceshelves/

LANSAT

ICE SHELF COLLAPSES,

23 February 2002

http://nsidc.org/iceshelves/

LANSAT

ICE SHELF COLLAPSES,

05 March 2002

http://nsidc.org/iceshelves/

LANSAT

Larsen B Break-up 2002

10,000 years of ice gone in one month!

Ted Scambos, NSIDCMODIS Image

March 17

Global Warming Art by Robert A. Rohde

IPCC, 2007

SLR1961-2003: 1.8 mm/y

1993-2003: 3.1 mm/y

IPCC, 2007

IPCC AR4

Salomon et al., 2009, PNAS

Cayo Pelón, Venezuela

SEA LEVEL RISE by 21001 m or moreCopenhagen, March 2009

Bob Thomas, Chincoteague Island, Va, USA

Thawing of frozen ground

Thawing of frozen soil and rock in high-mountain areas can produce slope instability and rock falls. A reported case linked to warming is the exceptional rock fall activity in the Alps during the 2003 summer heat wave, when the active layer in the Alps deepened significantly, by 30% to 100% of the depth measured before the heat wave (Gruber, 2004, permafrost; Schär, 2004, role; Noetzli, 2003, permafrost).

The number of travel days for oil exploration on Alaskan tundra has been decreasing over recent decades as the opening dates come later and the closing dates come earlier (ACIA 2003)

Air temp. N of 65ºN

NH sea ice

NH frozen ground

NF snow cover

Global glacier mass balance

SH sea ice

Air temp. S of 65ºSIPCC. 2007

Artic Drainage Warming LakesEarlier Stream flow

Hydrology and Water Resources

Historical and recent measurements from Lake Tanganyika, East Africa

Upper mixed layer (surface water temperatures

Deep-water (600 m) temperatures

Depth of the upper mixed layer

Error bars represent standard deviations

O’Reilly et al., 2003

Warming Lakes In East Africa

IMPACTOS BIOLOGICOS

IPCC AR4 2007 WGII Approximately 20-30% of plant and animal species assessed so far are likely to be at increased risk of extinction if increases in global average temperature exceed 1.5-2.5°C.

http://farm1.static.flickr.com/64/207836370_501760ba77.jpg

http://www.mbari.org/highCO2/

CORAL BLEACHING

Greening of the Arctic IPCC, 2007

Spring Events are Advancing

Spring phenological changes in birds and plants and their triggering by spring temperature are often similar as described by some cross-system studies;

The NAO influence is lower than the temperature trigger and is restricted to certain time periods (Walther et al. 2002)

Anomalies of spring phenological phases of birds

and trees in Germany

Species are Moving Poleward and Upward

Significant range shifts of more than 1,700 species averaging 6.1 km per decade toward the poles (or meters per decade upward), and significant mean advancement of spring events by 2.3 days per decade.

Temporal and spatial ‘sign-switching’ was found for 279 species. While the community and temporal sign-switching pattern was shown in diverse taxa studies, the species showing spatial sign switching pattern were northern hemisphere butterflies, such as Clossiana dia of France.

Simon Coombes

Parmesan and Yohe (2003)

Estimated changes in net primary productivity (NPP) (1982-1999) derived from independent NDVI data sets from the Global Inventory Monitoring and Modelling Studies (GIMMS) and Pathfinder Advanced Very High Resolution Radiometer (AVHRR) Land (PAL) (Nemani et al.,2003). An overall increase in NPP is observed, which is consistent with rising atmospheric CO2 and warming.

Trend in Many Regions towards

Earlier ‘Greening’ of Vegetation in the Spring

and Increased Net Primary Production

Global Terrestrial Changes

We examined 23 years of migration timing data collected at two capture locations in the Connecticut River drainage. We found that both dates of first capture and median capture dates have shifted significantly earlier by about 0.5 days/year.

We also quantified changes… of more northerly stocks in Maine and Canada. We found that the changes in migration timing were not unique to the Connecticut River stock and instead observed coherent patterns in the shift toward earlier peak migration dates across systems.

These consistent shifts are correlated with long-term changes in temperature and flow and may represent a response to global climate change

Juanes 2004

Return timing by day vs. year for Salmo salar collected at the Millbank trap in the Miramichi River, New Brunwick.

North America Salmon Migration

Marine

Global annual ocean primary production decreased from the CZCS era (1979-1986) to the present (1997-2002) by 6.3% (P<0.05). High latitude losses were 2.0 Pg C y -1, which accounted for 70% of the global decline in photosynthetic carbon uptake.

Gregg et al., 2003

In addition …

Long-term changes in the mean number of marine plankton species per association in the North Atlantic from 1960 to 1999 (Beaugrand et al. 2002)

Shifts to Temperate Species in North Atlantic Marine Ecosystems

All biological variables in the North Atlantic exhibited a pronounced change which started after circa 1982 for krill (decline), 1984 for the total abundance of copepods (increase), and 1988 for salmon (decrease).

The regional temperature increase therefore seems to be an important parameter that is at present governing the dynamic equilibrium of northeast Atlantic pelagic ecosystems.

North Atlantic Plankton and Fish

Krill

Copepods

Salmon

Beaugrand 2003

SST

Krill–ice relationships. Annual mean density of krill across the SW Atlantic versus a, sea-ice duration27 and b, the mean September latitude of 15% ice cover along a transect10 across the western Scotia Sea.

Krill density in the SW Atlantic sector from post-1976 krill data from scientific trawls. Green spots denote cells usable in thespatio-temporal model.

Southern Ocean and Plankton

Black line = total area burned anomalies over Canada for each 5 yr period 1920- 1999, in units of 105 km2.

Red line = 5 yr mean observed May- August temperature anomalies weighted by area burned, in K.

Green line = ensemble-mean 5 yr mean May-August area burned-weighted temp. anomalies CGCM2 model forced with anthropogenic GHGs and sulfate aerosols.

Gray lines = 5-95% range of internal variability in area burned, estimated from interannual variability.

Anomalies are calculated relative to the 1920-1999 mean.

Gillet et al. 2004

Forest Fires

1. Human emissions of greenhouse gases and sulfate aerosols have had a detectable warming effect during the fire season in Canada

2. Human-induced climate change has had a significant effect on the area burned by forest fires in Canada.

IMPACTOS HUMANOS

Arctic RegionHuman Systems

•Warming is disrupting indigenous hunting and food sharing as reduced sea ice causes the animals on which they depend to decline.

•Roads are sinking into melting permafrost, or being inundated by rising seas

•Reduced sea ice is a causing increases in coastal erosion.

ACIA 2004

Risks to Unique and Threatened Systems

NARA, 2005

Spread was observed into higher :• latitudes (Sweden: milder winters, early arrival of springs)• altitudes (the Czech Republic: shift from 700 to 1,100 m).

Lyme borreliosis and tick-borne encephalitis (Ixodes ricinus) have become more frequent in many places

Key measures include:• TBE vaccination• protective measures

– wearing suitable clothing– self-inspection after

outdoor activities to remove ticks early

Picture from Lindgren et al, Env. Health Perspect, 2000

Experience Infectious disease vectors in some areas

Heat-related Mortality in France

IPCC, 2007 WGII Latin America

CONCLUSIONES

IPCC AR4

Smith et al., PNAS, 2008