Alex Ruane

1. COP26 – IPCC North and Central America Event -- November 9th, 2021
Impacts- and Risk-relevant Climate Changes
in North and Central America
Alex Ruane
Coordinating Lead Author for WGI Chapter 12:
Climate change information for regional impact and for risk assessment

2. Regional Climate Information
Highlights of WGI Report
 WGI goes more firmly connects the dots between human actions and observed
changes in average and extreme climate conditions
 New emphasis on regional climate changes and actionable climate information
 More regional, more targeted to nature and society, clear confidence levels
 IPCC provides a useful starting point for mitigation, adaptation and risk planning
 Information oriented toward specific regions and sectors
2

3. Inventory of Risk-Relevant
Climate Change Factors
3
RELEVANT
FOR
LAND
REGIONS
RELEVANT
FOR
OCEAN
REGIONS
RELEVANT
FOR
LAND
REGIONS
RELEVANT
FOR
OCEAN
REGIONS
Climatic Impact-Drivers
Adopted from IPCC WGI (2021)
Figure SPM.9; see also WGI Chapter 12
Ranasinghe et al. (2021)

4. Sectoral Connections
For each important aspect of climate change
4
Terrestrial and Marine Ecosystems
Water Resources // Cities // Health
Poverty/Livelihoods (***includes agricultural land) 4
Each climate change can affect multiple sectors
Each sector is affected by multiple climate changes
Table 12.2
flood
flood

5. Mean Changes for
North and Central American Regions
5
IPCC North America Fact Sheet

6. Figure 12.4
Outdoor heat tolerance
thresholds more frequently exceeded
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• Each category of climate information can
be further elaborated with useful indices
and metrics
• Changes in intensity, frequency, duration,
seasonal timing and spatial extent are
foundation for resilience planning
Number of days per year where NOAA Heat Index
indicates “dangerous” conditions
Mid-century under a high emissions pathway

7. Figure 12.10
7
Change in Snow suitable for skiing

8. Regional CID changes
This table shows aggregated changes in CIDs across North and Central America
• 2050s time frame (~2℃ Global Warming Level under SSP3-7.0) compared to recent past
• Footnotes describe sub-regional and seasonal patterns in changes
• Dots describe time frame of regional emergence; finer patterns merit further analysis 8
Tables
12.8,
12.6,
12.9

9. 9

10. Summary
 IPCC Sixth Assessment Report provides the starting point for latest
regional climate information to support decision making for action!
 Concerted effort to connect the dots from human influence to
observed and projected changes for risk-relevant climate factors
 Implications for North and Central America:
• Multiple climate changes already observed in all regions
• Changes will be more widespread and pronounced with each ton of greenhouse gas
emissions
• Stronger basis of climate information for adaptation, mitigation and risk planning
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Happy to follow-up! alexander.c.ruane@nasa.gov

11. 11
Extra Slides

12. 12

13. 13

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15. 15

16. Local climate changes
vs. Global Warming Levels
Many Climatic Impact-Drivers respond rapidly to
Global Warming Level (GWL; vs. pre-industrial conditions)
Some Climatic Impact-Drivers respond more slowly
(e.g., ice, oceans)
Time does matter for adaptation, mitigation and risk management!!!
Figure
11.3
Global Warming Level (℃)
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17. 17