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1 Climate Change & Biodiversity. 2 CO 2 and global temperature.

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Presentation on theme: "1 Climate Change & Biodiversity. 2 CO 2 and global temperature."— Presentation transcript:

1 1 Climate Change & Biodiversity

2 2 CO 2 and global temperature

3 3 CO 2 increased 35% since industrial revolution Exceeds natural range over past 650,000 yrs 0.8 o C increase in global average temperature since 1906 Rate of warming doubled in past 50 years 1990s warmest decade, 1980s second warmest

4 4 Northern Hemisphere Ice Arctic ice: shrinking 7.8% per decade (3 x faster than GCM projections), historic low in 2007, 20% below previous record (2005)

5 5

6 6 Muir Glacier, Alaska 1941 2004

7 7 What about the future?

8 8 But: CO 2 has almost tripled since the 1990s from 1.1% pa to 3.1% in the 2000s Sea levels also rising faster than IPCC projections

9 9 Global Temperature Projections

10 10 Temperatures increased 0.9 o C since 1950 Frequency of hot days and nights increased Recent droughts hotter Australian trends

11 11 2005: Warmest year on record (>1 o C above long-term average) 2007: Warmest year on record in southern Australia, 6 th warmest overall

12 12 Rainfall very variable Decreased along east coast and SW WA Increased in north west Snow depth declined 40% since 1960s Australian trends

13 13 Temperature will increase: + 1 o C by 2030 + 0.8-2.8 o C by 2050 + 1-5 o C by 2070 Rainfall will change –Little change in north –Decrease of 2-5% elsewhere by 2030 Further declines in snow Increased drought, especially in SW Increase in fires Sea level will rise What do we expect in Australia?

14 14 Natural ecosystems and biodiversity

15 15 1. Directly: Temperature Rainfall CO 2 Extreme events 2. Indirectly: Interactions with other species Species & communities will be affected

16 16 Increased temperature Will affect: Photosynthesis Respiration Decomposition Metabolic rate Survivorship Timing of life cycles

17 17 Indirect Impacts e.g. Herbivory Reduced C:N Increased consumption Reduced survival & reproduction Increased development time Increased CO 2

18 18 Winners Short generation times Good dispersal Broad climatic tolerances Generalists Opportunists

19 19 Losers Long generation times Poorly dispersed Narrow climatic tolerances Specialists Large home ranges Isolated populations Genetically impoverished

20 20 What do we expect? Some species will move: eg. away from current cold boundary south up BUT: Some species will lose much of their current habitat

21 21 Southward range expansions observed for several bird species eg: Figbird, Channel-billed cuckoo, Black-necked Stork and Pied Heron, Noisy Pitta, Pacific Baza, Beach Thick Knee, Hooded Plover Observed changes

22 22 + 1 deg. 86% + 3.5 deg. 7% Grey-headed Robin Present

23 23 + 1 deg. 46% + 3.5 deg. 0% Lemuroid Ringtail Possum Present (Williams et al. 2003)

24 24 What do we expect? (cont) Advances in life cycles eg earlier flowering, fruiting, egg laying, migration

25 25 Since 1960: Migratory birds arriving 3.5 days per decade earlier & departing 5.1 days per decade later Beaumont et al. 2006

26 26 Alpine zone Coastal wetlands Freshwater wetlands & rivers North QLD Wet Tropics South-west WA Coral reefs Most at risk..

27 27 Alpine zone < 0.15% of land surface Low altitudinal relief Many species already threatened 40% reduction in snow cover and duration since 1960s

28 28 Duration of snow cover, Australian Alps Modelled current Moderate climate change : 0.3 o C increase More severe climate change : +1.3 o C increase, -8% precipitation www.greenhouse.gov.au

29 29 Predicted impacts eg Burramys parvus, mountain pygmy possum, < 500 individuals, confined to 10 km 2 habitat Dependent on snow cover for hibernation Bioclimate projected to disappear with 1 o C warming

30 30 Coastal wetlands Already experienced major losses in area Vulnerable to sea level rise, tidal surges and changes in precipitation Ongoing reductions in saltmarsh communities (up to 80% area in some locations) Some mangrove communities extending landwards

31 31 Mangroves encroaching on freshwater wetlands - associated with sea level and rainfall changes - 17,000 ha freshwater wetlands replaced by 4 km intrusion of mangroves in Mary River system, since 1940s Northern Territory rivers

32 32 Freshwater wetlands & riverine environments Already severely degraded Will be affected by further reductions in flows if rainfall declines concurrently with warming

33 33 Wet Tropics World Heritage Area Temperature increase ( o C) No. species losing core climatic habitat 11 3.530 557 765

34 34 Coral Reefs 1998: highest SSTs on record Feb-April 1998: most severe & widespread bleaching on GBR so far Unmatched in period 1903-1999 By 2030, bleaching may occur annually Potential replacement of coral by algal communities

35 35 Conclusions Climate change is already here Plants and animals are already responding We need to: Drastically reduce our greenhouse gas emissions Think about how to help species and ecosystems adapt to inevitable change

36 36


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