Download Comment fonctionne le GIEC et que dit

Comment fonctionne le GIEC et que
dit-il vraiment sur les changements
climatiques ?
Jean-Pascal van Ypersele
Vice-président du GIEC
Université catholique de Louvain, Académie royale de Belgique
@JPvanYpersele sur Twitter
Collège Belgique, Bruxelles, 6 mai 2014
© Yann Arthus-Bertrand / Altitude
Merci aux Services fédéraux de la Politique scientifique (BELSPO) pour leur soutien
http://www.motherjones.com/kevin-drum/2012/10/lying-statistics-global-warming-edition
Lying With Sta,s,cs, Global Warming Edi,on http://www.motherjones.com/kevin-drum/2012/10/lying-statistics-global-warming-edition
Lying With Sta,s,cs, Global Warming Edi,on http://www.motherjones.com/kevin-drum/2012/10/lying-statistics-global-warming-edition
Observed Arctic September sea ice extent
Cherry-picking analysis
September 2013
5.35 million km²
- « Arctic sea ice cover is rebounding »
+47%
September 2012
3.63 million km²
- « Warming of the 1980s, 1990s
and 2000s has stopped »
- « Climate is cooling »
Scientific approach: the full view
- Variability of September sea ice extent at the
interannual time scale is pronounced
- Significant negative trend over record period
(1979-2013): −0.89 million km²/decade
- September 2013 sea ice extent
is 6th lowest on record and 16.5%
below 1979-2013 average
Credit: F. Massonnet, UCL, 2013
Sea ice extent data: www.nsidc.org
Observed Arctic September sea ice extent
Cherry-picking analysis
September 2013
5.35 million km²
- « Arctic sea ice cover is
rebounding »
+47%
September 2012
3.63 million km²
- « Climate is cooling »
Scientific approach: the full view
- Variability of September sea ice extent
at the interannual time scale is
important
- Significant negative trend over record
period (1979-2013): −0.89 million km²/
decade
- September 2013 sea ice extent
is 6th lowest on record and 16.5%
below 1979-2013 average
Credit: F. Massonnet, UCL, 2013
Sea ice extent data: www.nsidc.org
Why the IPCC ? Established by WMO and UNEP in 1988
to provide policy-­‐makers with an objec,ve source of informa,on about •  causes of climate change, •  poten,al environmental and socio-­‐economic impacts, •  possible response op,ons (adapta,on & mi,ga,on). WMO=World Meteorological Organiza,on UNEP= United Na,ons Environment Programme Principles Governing IPCC Work
[...]
[...]
(1998, 2003, 2006, 2011)
Structure of the Intergovernmental Panel on Climate Change
IPCC Process (WGI):
Science Community
Lead Authors of Working Group
Election of WG Bureau
2008
2009
Governments
Scoping of Outline of the Fifth Assessment Report
Approval of Outline
Nomination and Selection of Experts
2010
2011
2012
Informal Review
0-Order Draft (ZOD)
Expert Review
1-Order Draft (FOD)
Expert Review
2-Order Draft (SOD)
Government Review
Final Draft
Government Review
2013
Sept
2013
Approval of SPM and Acceptance of Report
NB: Scientists have the last word on scientific accuracy
IPCC writing cycle (5 years, 2500
scientists)
•  Plenary decides table of content of reports
•  Bureau appoints world-class scientists as
authors, based on publication record
•  Authors assess all scientific literature
•  Draft – Expert review (+ Review editors)
•  Draft 2 (+ Draft 1 Summary for Policy Makers
(SPM) – Combined expert/government review
•  Draft 3 (+ Draft 2 SPM)– Government review of
SPM
•  Approval Plenary (interaction authors –
governments) – SPM and full report
•  NB: the authors have the last word for words that
are in the SPM
Jean-Pascal van Ypersele
([email protected])
Completed IPCC Reports 5 Assessment Reports (1990, 1995, 2001, 2007, 2013-­‐14) 1992 Supplementary Report and 1994 Special Report 8 Special Reports (1997,1999, 2000, 2005, 2011) Guidelines for Na@onal GHG Inventories, Good Prac@ce Guidance (1995-­‐2006) 6 Technical Papers (1996-­‐2008) Recent/Coming IPCC Products •  2011: Special report on Renewable
Energy Sources and Climate Change
Mitigation
•  2011: Special Report on Managing the
Risks of Extreme Events and Disasters to
Advance Climate Change Adaptation
•  2013: AR5 WGI report (physical science)
•  2014: AR5 WGII (Impacts & Adaptation);
WGIII (Mitigation), Synthesis Report
•  All available on www.ipcc.ch
Background
IPCC First
Assessment
Report - 1990
Climate
+ Impacts
(Costeffectiveness)
IPCC Second
Assessment
Report - 1995
Climate
+ Impacts
Costeffectiveness
Najam et al., 2003 and Alam, 2007
(Equity)
IPCC Third
Assessment
Report - 2001
Climate
+ Impacts
Costeffectiveness
Equity
(Alternative
Development
Pathway)
IPCC Fourth
Assessment
Report - 2007
Climate
+ Impacts
Costeffectiveness
Equity
Alternative
Development
Pathway
(Sustainable
Development)
14
AR5 is the best ever
15
•  Better integration of Mitigation and Adaptation
•  Improved risk-management approach
•  Evolving away from the non-mitigation SRES
scenarios (SRES= Special Report on Emission Scenarios, 2000)
•  Special effort to provide regional information
when available
•  Sustainable development & equity aspects
•  More comprehensive treatment of economic
aspects, and of cross-cutting issues
•  Emerging issues handled (geo-engineering, …)
•  Better handling & communication of
uncertainties
The IPCC assessments have influenced global
action on an unprecedented scale
1. The First Assessment Report (FAR, 1990) had a major
impact in defining the content of the UNFCCC
2. The Second Assessment Report (SAR, 1996) was
largely influential in defining the provisions of the Kyoto
Protocol
3. The Third Assessment Report (TAR, 2001) focused
attention on the impacts of climate change and the need
for adaptation
4. The Fourth Assessment Report (AR4, 2007) informed
the decision on the ultimate objective (2°C) and is
creating a strong basis for a post Kyoto Protocol
agreement
5. The Fifth Assessment Report (AR5, 2013-14) will
inform the review of the 2°C objective, and be the
context for preparing the post-Durban 2015 agreement
What is happening in the
climate system?
What are the risks?
What can be done?
WG I (Physical science basis): 209
lead authors, 2014 pages, 54.677
review comments
WG II (Impacts, Adaptation, and
Vulnerability): 243 lead authors, 2500
pages, 50.492 review comments
WG III (Mitigation of Climate
Change): 235 coordinating and lead
authors, 2000 pages, 38.315 review
comments
What is happening in the
climate system?
Principaux messages du SPM
19 messages-clés
En moins de 2 pages
Résumé pour les décideurs
~14.000 Mots
14 Chapitres
Atlas des Projections Régionales
54.677 Commentaires
de 1089 Experts
2010:
209 Auteurs sélectionnés
les grandes
lignes du WGI approuvées
2009:
20 (IPCC 2013, Fig. SPM.1b)
Evolution de la température moyenne en surface 1901-2012: +0.89°C
Le réchauffement du système climatique est
sans équivoque
(IPCC 2013, Fig. SPM.1a)
Chacune des trois dernières décennies a été successivement plus
chaude à la surface de la Terre que toutes les décennies
précédentes depuis 1850
Dans l’hémisphère nord, la période 1983–2012 a probablement été́ la
période de 30 ans la plus chaude des 1400 dernières années (degré
de confiance moyen).
Que dit le GIEC sur le « ralentissement du réchauffement »
-  En raison de la variabilité naturelle, les tendances
calculées sur des séries courtes sont très
sensibles à la date de début et de fin de la
période considérée, et ne reflètent généralement
pas les tendances climatiques
-  Le taux de réchauffement calculé sur la période
1998-2012 est de +0.05°C/décennie (début lors
d’un fort événement El Niño), alors que celui calculé
sur la période 1996-2010 est de +0.14°C; la
tendance calculée sur 1951-2012 étant de 0.12°C/
décennie
Que dit le GIEC sur le « ralentissement du réchauffement »
-  La réduction observée de la tendance 1998-2012
par rapport à celle de 1951-2012 est due à parts à
peu près égales à :
-  une réduction du forçage radiatif
(principalement due à des éruptions
volcaniques et à la phase descendante du
cycle solaire) (degré de confiance faible)
-  Une contribution de la variabilité interne,
dont une possible redistribution de la
chaleur au sein de l’océan (degré de
confiance moyen)
Change in global average upper ocean heat content
AR5 WGI SPM - Approved version / subject to final copyedit
Extension of the Arctic ice cap
September 1979
September 2005
September 2007
The pink line indicates the average ice cap extension since 1979
Plateau Glacier (1961) (Alaska) hJp://www.weather.com/news/science/environment/alaskas-­‐glaciers-­‐capturing-­‐earth-­‐
changing-­‐our-­‐eyes-­‐20131125?cm_ven=Email&cm_cat=ENVIRONMENT_us_share Plateau Glacier (2003) (Alaska) hJp://www.weather.com/news/science/environment/alaskas-­‐glaciers-­‐capturing-­‐earth-­‐
changing-­‐our-­‐eyes-­‐20131125?cm_ven=Email&cm_cat=ENVIRONMENT_us_share Change in average sea-level change
AR5 WGI SPM - Approved version / subject to final copyedit
Atmospheric CO2 concentration
AR5 WGI SPM - Approved version / subject to final copyedit
2013
+40%
(Lüthi et al.,2008, NOAA)
The atmospheric concentrations of carbon dioxide,
methane, and nitrous oxide have increased to levels
unprecedented in at least the last 800,000 years.
Carbon cycle: unperturbed fluxes
Atmosphere
280 ppmv
(1ppmv = 2.2 GtC)
pre-ind : 597 GtC
Physical, 70.5
Chemical, and
Biological
processes
photosynthesis
119.5
120
respiration
70
Ocean
2300
38000
3700
Units: GtC (billions tons of carbon) or GtC/year (multiply by 3.7 to get GtCO2)
[email protected]
Carbon cycle: perturbed by human activities
(numbers for the decade 1990-1999s, based on IPCC AR4)
Atmosphere
280 ppmv + 1.5 ppmv/yr (1ppmv = 2.2 GtC)
pre-ind : 597GtC + 3.2/yr
70.5
photosynthesis
119.5
120
2.6
sinks
respiration
70
Physical,
Chemical, and
Biological
processes
1.6
déforestation
(& land use changes)
2.2
6.4
Fossil fuels
Ocean
2300 -40
38000 +120
3700 -244
Units: GtC (billions tons of carbon) or GtC/year
[email protected]
Stocks!
The carbon cycle is policy-­‐relevant •  CO2 accumulates in the atmosphere as long as human emissions are larger than the natural absorp,on capacity •  Historical emissions from developed countries therefore maXer for a long ,me •  As warming is func,on of cumulated emissions, the carbon « space » is narrowing fast (to stay under 1.5 or 2°C warming) Tyndall (1861) mesure l’absorption du rayonnement par les gaz
© IPCC 2013
Fig. SPM.5
CO2 provides
largest RF
Observed
Anthropogenic
Aerosols
© IPCC 2013
CO2, CH4, N2O
Solar, Volcanic
Internal Variability
Fig. TS.10
Global mean warming since 1951 (°C)
Human influence on the
climate system is clear.
Contenu thermique des océans
(IPCC 2013, Fig. SPM.6)
Température moyenne
surface des continents
Noir: observations
Bleu: simulations avec seuls facteurs naturels
Rose: simulations avec facteurs naturels & humains
L’influence humaine sur le système climatique est
sans équivoque; Il est extrêmement probable (95%)
que l’influence humaine a été la cause principale du
réchauffement depuis le milieu du 20ème siècle
(IPCC 2013, Fig. SPM.7a)
(Ref: 1986-2005)
Le changement de la température moyenne du globe en surface
pour la fin du XXIe siècle dépassera probablement 1,5°C
relativement à 1850-1900 pour tous les scénarios sauf pour le
RCP2.6.
Dépassement probable de 2°C pour RCP6 et RCP8.5
Global mean surface temperature change projections
Increase from end of 20th century to end of 21st century
mean
likely range
RCP2.6
1.0
0.3 to 1.7
RCP4.5
1.8
1.1 to 2.6
RCP6
2.2
1.4 to 3.1
RCP8.5
3.7
2.6 to 4.8
(°C)
AR5 WGI SPM - Approved version / subject to final copyedit
Surface temperature projections
AR5 WGI SPM - Approved version / subject to final copyedit
Precipitation projections
(IPCC 2013, Fig. SPM.9)
(Ref: 1986-2005)
Le niveau moyen des mers continuera à
s’élever au cours du XXIe siècle
Northern Hemisphere September sea ice
Extension de la glace
extentde mer en Arctique
Global ocean surface pH (projections)
Ocean Acidification, for RCP 8.5 (orange) & RCP2.6 (blue)
Oceans are Acidifying Fast…
Changes in pH over the last 25 million years
“Today is a rare
event in the
history of the
World”
•  It is happening now, at a speed and to a level not experienced by marine
organisms for about 60 million years
• Mass extinctions linked to previous ocean acidification events
•  Takes 10,000’s of years to recover
Turley et al. 2006
Slide courtesy of Carol Turley, PML
Since 1950, extreme hot days and heavy
precipitation have become more common
There is evidence that anthropogenic influences, including increasing atmospheric
greenhouse gas concentrations, have changed these extremes
48
Extreme weather and climate events IPCC, AR5, Table SPM.1 © IPCC 2013
Fig. SPM.10
Cumulative emissions of CO2 largely determine global mean
surface warming by the late 21st century and beyond.
(IPCC 2013, Fig. SPM.10)
(1PgC = 1GtC)
Le total des émissions de CO2 cumulées détermine dans
une large mesure la moyenne globale du réchauffement
en surface vers la fin du XXIème siècle et au delà
© IPCC 2013
Fig. SPM.10
Limiting climate change will require substantial and
sustained reductions of greenhouse gas emissions.
Le nouveau budget carbone (Ref: AR5 WGI SPM)
Limiter le réchauffement dû aux seules émissions anthropiques de CO2 à
moins de 2°C relativement à 1861-1880, avec une probabilité (…) > 66%
nécessitera que les émissions cumulées de toutes les sources anthropiques
de CO2 soient (…) comprises entre 0 et 1000 GtC depuis cette période.
L[a] borne supérieure de cette estimation est réduite à environ 800 GtC, si
l’on prend en compte les forçages autres que celui du CO2 comme dans le
scénario RCP2.6. depuis cette période.
En 2011, le total déjà émis s’élevait à 531 [446 à 616] GtC.
Les estimations du dégazage de CO2 et CH4 vers l’atmosphère provenant de
carbone stocké dans des pergélisols fondant au cours du XXIe siècle sont
comprises entre 50 et 250 GtC pour le scénario RCP8.5 (faible niveau de
confiance).
Le nouveau budget carbone (Ref: AR5 WGI SPM)
Résumons : Limiter l’augmentation de température à moins de 2°C avec
plus de deux chances sur trois d’y arriver nécessitera que les émissions
cumulées de toutes les sources anthropiques de CO2 soient inférieures à
1000 GtC, et même environ 800 GtC, si l’on prend en compte les forçages
autres que celui du CO2.
Mais on a déjà émis environ 530 GtC.
Et le dégazage de CO2 et CH4 provenant du pergélisol (permafrost)
ajouterait au cours du XXIe siècle entre 50 et 250 GtC pour le scénario
RCP8.5.
Il reste donc environ (800 - 530) – de 50 à 250 GtC, soit 220 à 20 GtC
dans le budget carbone si l’humanité veut rester sous l’objectif de 2°C !
What are the risks?
IPCC AR5 upper estimate by 2100
4.8
IPCC AR5 lower estimate by 2100
0.3
Adapted from: International Geosphere Biosphere Programme Report no.6,
Global Changes of the Past, July1988
18-20000 years ago (Last Glacial Maximum)
With permission from Dr. S. Joussaume, in « Climat d’hier à demain », CNRS éditions.
Today, with +4-5°C globally
With permission from Dr. S. Joussaume, in « Climat d’hier à demain », CNRS éditions.
THE WORKING GROUP II
CONTRIBUTION TO THE IPCC'S
FIFTH ASSESSMENT REPORT
IMPACTS
EMISSIONS
and Land-use Change
Risk = Hazard x Vulnerability x Exposure (Katrina flood vic,m) AP Photo -­‐ Lisa Krantz (hJp://lisakrantz.com/hurricane-­‐katrina/zspbn1k4cn17phidupe4f9x5t1mzdr) VULNERABILITY
AND EXPOSURE
AROUND THE WORLD
VULNERABILITY
AND EXPOSURE
AROUND THE WORLD
WIDESPREAD
OBSERVED IMPACTS
A CHANGING WORLD
WIDESPREAD
OBSERVED IMPACTS
A CHANGING WORLD
Effects on Nile delta: 10 M people
above 1m
(Time 2001)
More heavy precipitation and more droughts….
•  Warmer world implies more evaporation - more water goes
to the atmosphere where water is available on the ground
(e.g., oceans). The atmosphere therefore will contain more
water vapor available to rain out. And most places receive
the majority of their moisture in heavy rain events, which
draw moisture from a big area.
•  Warmer world implies more evaporation but soils will dry out as a result. So dry
regions will get drier unless storm tracks
shift in a lucky way. And for some, they are
expected to shift in an unlucky way.
• At mid to low latitudes - wet get wetter,
dry get drier
ADAPTATION IS
ALREADY OCCURRING
ADAPTATION IS
ALREADY OCCURRING
CLIMATE CHANGE
REDUCING AND
MANAGING RISKS
INCREASING MAGNITUDES
OF WARMING INCREASE
THE LIKELIHOOD OF
SEVERE AND
PERVASIVE IMPACTS
RISKS OF
CLIMATE CHANGE
INCREASE
WITH CONTINUED
HIGH EMISSIONS
AR5, WGII, Box SPM.1 Figure 1 Risk-Level
Very
Low
Med
Very
High
Present
Near Term (2030-2040)
Long Term 2°C
(2080-2100) 4°C
Risk Level with
High Adaptation
Potential for
Additional
Adaptation to
Reduce Risk
Risk Level with
Current Adaptation
What can be done?
Compatible fossil fuel emissions simulated by
the CMIP5 models for the four RCP scenarios AR5 WGI TS – Fig TS 19
Trends in stocks and flows of greenhouse gases
•  Emissions are rising faster than ever before.
From 1970 to 2000: +1.3%/year; from 2000 to 2010:
+2.2%/year. Total GHG emissions in 2010: 49
Gigatonnes CO2 equivalent.
•  CO2 represented 76% of total GHG emissions in
2010
•  The carbon content of energy has increased over
the last decade, reversing a declining trend since
1970. This is caused by an increase in the relative
use of coal.
Working Group III contribu@on to the IPCC Fidh Assessment Report GHG emissions accelerate despite reduction efforts. Most emission
growth is CO2 from fossil fuel combustion and industrial processes.
Working Group III contribu@on to the IPCC Fidh Assessment Report Trends in stocks and flows of greenhouse gases
•  Without additional efforts, current trends are
expected to lead to a 3.7 to 4.8°C increase of
global temperatures by 2100, compared to preindustrial levels, with further increases
thereafter. Taking into account climate uncertainty,
the range in 2100 becomes 2.5 to 7.8°C in 2100.
Working Group III contribu@on to the IPCC Fidh Assessment Report Without more mitigation, global mean surface temperature
might increase by 3.7° to 4.8°C over the 21st century.
Working Group III contribu@on to the IPCC Fidh Assessment Report Can temperature rise still be kept below 1.5 or 2°C
(over the 21st century) compared to pre-industrial ?
•  Many scenario studies confirm that it is technically
and economically feasible to keep the warming
below 2°C, with more than 66% probability (”likely
chance”). This would imply limiting atmospheric
concentrations to 450 ppm CO2-eq by 2100.
•  Such scenarios for an above 66% chance of staying
below 2°C imply reducing by 40 to 70% global GHG
emissions compared to 2010 by mid-century, and
reach zero or negative emissions by 2100.
Working Group III contribu@on to the IPCC Fidh Assessment Report Can temperature rise still be kept below 1.5 or 2°C
(over the 21st century) compared to pre-industrial ?
•  These scenarios are characterized by rapid
improvements of energy efficiency and a near
quadrupling of the share of low-carbon energy
supply (renewables, nuclear, fossil and bioenergy
with CCS), so that it reaches 60% by 2050.
•  Keeping global temperature increase below 1.5°C
would require even lower atmospheric
concentrations (<430 ppm CO2eq) to have a little
more than 50% chance. There are not many scenario
studies available that can deliver such results,
requiring even faster reductions in the medium term,
indicating how difficult this is.
Working Group III contribu@on to the IPCC Fidh Assessment Report Can temperature rise still be kept below 1.5 or 2°C
(over the 21st century) compared to pre-industrial ?
•  Both categories of scenarios (< 1.5 and < 2°C) typically
rely on the availability and widespread deployment of
BECCS (Bioenergy with Carbon dioxide Capture and
Storage) and afforestation after 2050. There is only limited
evidence for such a potential, and BECCS entails
challenges and risks (including large-scale biomass
provision, and the CCS technology itself).
Working Group III contribu@on to the IPCC Fidh Assessment Report Can temperature rise still be kept below 1.5 or 2°C
(over the 21st century) compared to pre-industrial ?
•  Average global macro-economic costs of such
reduction pathways that minimize costs over the
century are modest compared to expected
economic growth. The assumptions used for this
“ideal” cost-effective approach include mitigation
action starting immediately in all countries, a
global carbon price and all key technologies
available. With those assumptions, the global
macro-economic costs of a 2°C scenario are limited:
an average annual reduction of consumption of
about 0.04-0.14 percentage points (from a baseline
increase of consumption of 1.6-3% per year).
Working Group III contribu@on to the IPCC Fidh Assessment Report Can temperature rise still be kept below 1.5 or 2°C
(over the 21st century) compared to pre-industrial ?
•  There are also benefits from avoided climate
change impacts and co-benefits in other areas,
such as reduced health and ecosystem damages
due to air pollution, improved energy security,
food security, or employment. There is also a
wide range of possible adverse side effects from
climate policy that have not been well-quantified.
Working Group III contribu@on to the IPCC Fidh Assessment Report Mitigation can
result in large
co-benefits for
human health
and other
societal goals.
Can temperature rise still be kept below 1.5 or 2°C
(over the 21st century) compared to pre-industrial ?
•  Estimated global GHG emissions levels in 2020 based on
the Cancún Pledges are not consistent with cost‐effective
long‐term mitigation trajectories that have at least 50%
chance to limit global temperature change to 2°C relative to
pre‐industrial levels.
•  Meeting this goal would require further substantial
reductions beyond 2020.
•  The Cancún Pledges are broadly consistent with cost‐
effective scenarios that are likely to keep temperature
change below 3°C relative to preindustrial levels.
Working Group III contribu@on to the IPCC Fidh Assessment Report All sectors and regions have the
potential to contribute by 2030
(avoided emissions: the higher, the better)
IPCC AR4 (2007)
Note: estimates do not include non-technical options, such as lifestyle changes.
IPCC
The more we wait, the more difficult it will be
Jean-Pascal van Ypersele
([email protected])
Mitigation requires changes throughout the economy.
Efforts in one sector determine mitigation efforts in others.
Working Group III contribu@on to the IPCC Fidh Assessment Report Substantial reductions in emissions would require large
changes in investment patterns.
Working Group III contribu@on to the IPCC Fidh Assessment Report Since AR4, there has been an increased focus on policies
designed to integrate multiple objectives, increase cobenefits and reduce adverse side-effects.
• 
Sector-specific policies have been more widely used than economywide policies.
• 
Regulatory approaches and information measures are widely used,
and are often environmentally effective.
• 
Since AR4, cap and trade systems for GHGs have been established in a
number of countries and regions.
• 
In some countries, tax-based policies specifically aimed at reducing
GHG emissions–alongside technology and other policies–have helped to
weaken the link between GHG emissions and GDP
• 
The reduction of subsidies for GHG-related activities in various sectors
can achieve emission reductions, depending on the social and economic
context.
Working Group III contribu@on to the IPCC Fidh Assessment Report Effective mitigation will not be achieved if individual agents
advance their own interests independently.
•  Existing and proposed international climate change cooperation
arrangements vary in their focus and degree of centralization and
coordination.
•  Issues of equity, justice, and fairness arise with respect to
mitigation and adaptation.
•  Climate policy may be informed by a consideration of a diverse
array of risks and uncertainties, some of which are difficult to
measure, notably events that are of low probability but which would
have a significant impact if they occur.
Working Group III contribu@on to the IPCC Fidh Assessment Report “There is hope, modest hope”
(Co-chair WGIII Edenhofer)
Working Group III contribu@on to the IPCC Fidh Assessment Report Mitigation can
result in large
co-benefits for
human health
and other
societal goals.
Pour en savoir plus :
  www.ipcc.ch
: GIEC ou IPCC
  www.climatechange2013.org : GIEC WGI
  www.climate.be/vanyp : beaucoup de mes dias
et d’autres documents
  www.climate.be/pendules : ressources faciles
d’accès pour « remettre les pendules à l’heure »
  www.climate.be/desintox : réponses à la
désinformation
  On Twitter: @JPvanYpersele
Jean-Pascal van Ypersele
([email protected])