Presented by: Olivia Serdeczny
7.1 Appraising adaptation in the context of the less than 2 °C temperature limit
This session will look at how to put the less than 2°C global temperature limit into practice in choosing climate scenarios and in focusing adaptation assessment to these scenarios, thereby reducing the range of uncertainty that used to exist.
2. Slide
NDCs and timeline for 1.5oC and 2oC
warming
2
• Under current mitigation policies, we are heading to a
warming of 3.6°C
• If all NDC pledges are met, this puts us on a trajectory of
2.7°C
• Under NDC trajectories, warming is projected to cross
1.5°C by 2030–2045 and 2°C by 2045–2075 (Rogelj et al.
2016, Nature)
5. Slide
Selected sources of information
Inter-sectoral impact model intercomparison (ISIMIP)
data archive and publications
• Coherent climate impact simulations in 11 sectors, including:
• Agriculture
• Water
• Vector-borne diseases
• Coastal infrastructure
• Biomes
• Fisheries (in progress)
• Energy (in progress)
• Forests (in progress)
• Heat-related mortality & labour productivity
• Raw impact data available for RCP2.6 (1.5/2oC) and RCP8.5 (4oC)
• Data archive publicly accessible
• More information on data and results at www.isimip.org
5
13. Slide
Crop yields
13
1.5°C 2°C
Heat wave(warmspell) duration[month]
Global 1.1[1;1.3] 1.5[1.4;1.8]
Tropical regions up to 2 months at
1.5°C or up to 3 months at 2°C
Reductioninannual water availability[%]
Mediterranean 9[5;16] 17[8;28]
Other dry subtropical regions like
Central America and South Africa
also at risk
Increaseinheavyprecipitationintensity[%]
Global 5[4;6] 7[5;7] Global increase in intensity due to
warming;high latitudes (>45°N)
and monsoon regions affected
most.
SouthAsia 7[4;8] 10[7;14]
Globalsea-levelrise
in2100[cm] 40[30;55] 50[35;65] 1.5°C end-of-century rate about
30%lower than for 2°C reducing
long-term SLR commitment.2081-2100rate[mm/yr] 4[3;5.5] 5.5[4;8]
Fractionofglobal coral reefsat riskofannual bleaching[Constant case, %]
2050 90[50;99] 98[86;100] Only limiting warming to 1.5°C may
leave window open for some
ecosystem adaptation.2100 70[14;98] 99[85;100]
Changesinlocal cropyieldsover global andtropical present dayagricultural areas
includingtheeffectsofCO2-fertilization[%]
Wheat Global
Tropics
2[-6;17]
-9[-25;12]
0[-8;21]
-16[-42;14]
Projected yield reductions are
largest for tropical regions,while
high-latitude regions may see an
increase.Projections not including
highly uncertain positive effects of
CO2-fertilization project reductions
for all crop types of about 10%
globally already at 1.5°C and
further reductions at 2°C.
Maize Global
Tropics
-1[-26;8]
-3[-16;2]
-6[-38;2]
-6[-19;2]
Soy Global
Tropics
7[-3;28]
6[-3;23]
1[-12;34]
7[-5;27]
Rice Global
Tropics
7[-17;24]
6[0;20]
7[-14;27]
6[0;24]
Estimates do typically not include effects of extreme droughts, heat extremes,
saltwater intrusion or pests.
Schleussner et al. (2016)
15. Slide
Coral Reef Loss
15
Reductioninannual water availability[%]
Mediterranean 9[5;16] 17[8;28]
Other dry subtropical regions like
Central America and South Africa
also at risk
Increaseinheavyprecipitationintensity[%]
Global 5[4;6] 7[5;7] Global increase in intensity due to
warming;high latitudes (>45°N)
and monsoon regions affected
most.
SouthAsia 7[4;8] 10[7;14]
Global sea-level rise
in2100[cm] 40[30;55] 50[35;65] 1.5°C end-of-century rate about
30%lower than for 2°C reducing
long-term SLR commitment.2081-2100rate[mm/yr] 4[3;5.5] 5.5[4;8]
Fractionofglobal coral reefsat riskofannual bleaching[Constant case, %]
2050 90[50;99] 98[86;100] Only limiting warming to 1.5°C may
leave window open for some
ecosystem adaptation.2100 70[14;98] 99[85;100]
Changesinlocal cropyieldsover global andtropical present dayagricultural areas
includingtheeffectsofCO2-fertilization[%]
Wheat Global 2[-6;17] 0[-8;21] Projected yield reductions are
largest for tropical regions,while
1.5°C 2°C
Heat wave(warmspell) duration[month]
Global 1.1[1;1.3] 1.5[1.4;1.8]
Tropical regions up to 2 months at
1.5°C or up to 3 months at 2°C
Reductioninannual water availability[%]
Mediterranean 9[5;16] 17[8;28]
Other dry subtropical regions like
Central America and South Africa
also at risk
Schleussner et al. (2016)
It is estimated that only 5% of Kiribati's reefs will survive the current bleaching
thermal stress event. (NOAA Coral Reef Watch)
16. Slide 16
Sea Level Rise – Upper range projections
Turn Down the Heat 2014
Sea Level Rise projections (upper range) in a 1.5°C world. Increases are given for
the period 2081–2100 relative to 1986–2005
17. Slide
Risky know unknowns
17Dim
Coumou, Earth
System Analysis
Some large-scale processes in the Earth system are not
well reflected in current climate models, but could have
significant consequences for natural and human systems,
e.g.
• Atmospheric blocking events
• “Tipping points”
19. Slide
Increase in blocking events (July & August)
19
US heat &
drought events
Great European
Flood, floods in Pakistan
& western US
European
heat wave
US heat wave
Cental Asian heat wave
Pakistan flooding
Petoukhov et al, PNAS (2013)
Coumou et al, PNAS (2014)
• Since 1980: 19 periods with
anomalous jetstream patterns
identified
• Recent cluster since 2003
Doubling in Frequency
• Many associated with high-impact
extremes
20. Slide
Tipping points in the Earth System
Drijfhout et al. (2015)
• 37 abrupt shifts in climate
system identified in CMIP5
models
• Including biome changes,
permafrost loss, ocean
circulation changes, sea-ice
snow and glacier loss
• Steep increase between 1.5°C
and 2°C
• Tipping risks increase rapidly for
West Antartic and Greenland ice
sheets
21. Slide
Selected sources of information
World Bank´s Turn Down the Heat report series
• Temperature levels assessed: 1.5, 2, 4oC (where possible)
• WB regions: Latin America and the Caribbean; South East
Asia; South Asia; Europe and Central Asia; Sub-Saharan
Africa; Middle East and North Africa
• Regional and executive summaries translated into English,
Arabic, Chinese, French, Portuguese, Russian, Spanish
• Available at
http://www.worldbank.org/en/topic/climatechange/publi
cation/turn-down-the-heat
21
22. Slide
Selected sources of information
“Climate-Fact-Sheets” (KfW Development Bank and the Climate
Service Center Germany)
• Country-level projections of climate variables
• Based on primary data (e.g. projections from global and regional climate models
as well as global observational datasets) and literature review for variables
including
• Temperature (annual mean, minimum and maximum temperatures)
• Precipitation
• Wind speeds
• Heat waves and cold spells
• Dry spells
• More information and order form at
http://www.climate-service-center.de/036238/index_0036238.html.en
22
Notas del editor
Metric
Metric
CDD (consecutive dry days): annual
maximum number of consecutive days for which
the precipitation is below 1mm per day
Drijfhout, S. et al., 2015. Catalogue of abrupt shifts in Intergovernmental Panel on Climate Change climate models. Proceedings of the National Academy of Sciences, p.201511451. Available at: http://www.pnas.org/lookup/doi/10.1073/pnas.1511451112.
Abstract: Abrupt transitions of regional climate in response to the gradual rise in atmospheric greenhouse gas concentrations are notoriously difficult to foresee. However, such events could be particularly challenging in view of the capacity required for society and ecosystems to adapt to them. We present, to our knowledge, the first systematic screening of the massive climate model ensemble informing the recent Intergovernmental Panel on Climate Change report, and reveal evidence of 37 forced regional abrupt changes in the ocean, sea ice, snow cover, permafrost, and terrestrial biosphere that arise after a certain global temperature increase. Eighteen out of 37 events occur for global warming levels of less than 2°, a threshold sometimes presented as a safe limit. Although most models predict one or more such events, any specific occurrence typically appears in only a few models. We find no compelling evidence for a general relation between the overall number of abrupt shifts and the level of global warming. However, we do note that abrupt changes in ocean circulation occur more often for moderate warming (less than 2°), whereas over land they occurmore often forwarming larger than 2°. Using a basic proportion test, however, we find that the number of abrupt shifts identified in Representative Concentration Pathway (RCP) 8.5 scenarios is significantly larger than in other scenarios of lower radiative forcing. This suggests the potential for a gradual trend of destabilization of the climate with respect to such shifts, due to increasing global mean temperature change.
Levermann, A. et al., 2012. Potential climatic transitions with profound impact on Europe. Review of the current state of six “tipping elements of the climate system.” Climatic Change, 110(3-4), pp.845–878. Available at: http://www.springerlink.com/index/10.1007/s10584-011-0126-5 [Accessed June 23, 2011].
Abstract: We discuss potential transitions of six climatic subsystems with large-scale impact on Europe, sometimes denoted as tipping elements. These are the ice sheets on Greenland and West Antarctica, the Atlantic thermohaline circulation, Arctic sea ice, Alpine glaciers and northern hemisphere stratospheric ozone. Each system is represented by co-authors actively publishing in the corresponding field. For each subsystem we summarize the mechanism of a potential transition in a warmer climate along with its impact on Europe and assess the likelihood for such a transition based on published scientific literature. As a summary, the “tipping” potential for each system is provided as a function of global mean temperature increase which required some subjective interpretation of scientific facts by the authors and should be considered as a snapshot of our current understanding.