1. Climate Change Science
Presenter: Nathan Ross, ICLEI-A/NZ
Source: Dr. Andy Reisinger, Ministry for the Environment
Communities for Climate Protection® - New Zealand:
A New Zealand Government initiative delivered by ICLEI-A/NZ.
This programme is part of ICLEI’s international Cities for Climate Protection® Campaign.

2. Definitions:
The Greenhouse Effect
Global Warming
Climate Change

3. A look at long time scales – ice ages and our future
Source: CDIAC data center. Jouzel et al., Nature 399:

4. A look at long time scales – ice ages and our future
Source: CDIAC data center. Jouzel et al., Nature 399:

5. A look at long time scales – ice ages and our future
Source: CDIAC data center. Jouzel et al., Nature 399:

6. A look at long time scales – ice ages and our future
Temperatures will rise in response to the rising greenhouse gas concentrations.
CO2e concentrations are going into territory they have not been in for 20 million years.
Source: CDIAC data center. Jouzel et al., Nature 399:

7. Climate change – the immediate context – 1000 AD to 2100 AD

8. A look into the distant future – Why act now?
CO2 concentration, temperature and sea level will all continue to rise long after emissions are reduced.

9. Climate change effects for NZ:
Sea level rise: by 2100, a cm rise is most likely. (14-17cm rise over 20th century)
Temperatures: 1°C increase by the 2030s and 2-3°C by the 2080s (0.7°C increase over the 20th century)
Rain: more to fall in the west of the country, and less in the east – also more risk of heavy rainfall
Westerly winds to become more prevalent

10. Climate and Weather Extremes:
Local impacts of climate change may be felt most in extreme weather events
A small change in the average can lead to large changes in the extremes
Increase in frequency and severity of natural hazards (floods, storms and drought), and the costs of these events - heavy rain up to 4 times as frequent by 2070

11. What will these changes mean?
Climate Change will bring some opportunities to NZ:
Warmer winters to increase hydroelectric lake levels
Agricultural and forestry productivity to increase in some areas, also commercialisation of new crops
Health benefits and lower heating costs with warmer winters

12. What will these changes mean?
Climate Change will increase risks to NZ:
Agricultural and forestry pests and diseases
Water shortages, increased risk of droughts
Higher temperatures affect some crops
Heavy rainfall puts pressure on drainage and stormwater systems, increase in flood risk
Biodiversity – some species will fail to adjust to a changing climate, ie. changing habitat

13. RMA Amendment
RMA Amendment (March 2004) requires consideration of the effects of climate change in decision-making
Planning for natural hazards, resource use, land-use planning and designing new infrastructure and assets
Of particular importance are:
development decisions in areas prone to river and sea flooding
housing / infrastructure decisions in areas prone to coastal erosion
water use rights / irrigation scheme placement and design
infrastructure and asset design

15. top end
bottom end

16. Historical trend
No change

17. top end
Planning on the basis of historical data only is not a robust approach. We need to take climate change into account to plan for the future.
Data