Introducing alien ecosystem engineers to Round Island, Mauritius Species lost 2 giant tortoises Role dispersal of herbivore adapted seeds Surrogate species Aldabra Giant Tortoise Madagascar radiated tortoise 250 kg 16 kg
New topic Climate change and conservation
The main message Humans Climate Biodiversity Climate change is unequivocal Natural and human systems have been impacted Adaptation and mitigation are necessary Biodiversity/conservation plays a role in climate regulation Biodiversity/conservation is central to tackling climate change
Outline for Climate change and conservation Overview Recent changes to the climate Physical feedback loops Future Climate Change Biological Impacts Ecosystem feedback loops Conservation Implications
Climate shifts are due to change in the retention and distribution of solar energy Carbon dioxide, methane and water vapour are important in maintaining the current energy balance
Svante Arrhenius (1896) predicted the emission of CO 2 due to the combustion of coal will eventually warm the world Air bubbles in ice give CO 2 conc n of atmosphere at time of ice deposition Ratio of 18 O 2 and 16 O 2 can be used to calculate temperature at time ice is formed Record dating back 740,000 years
CO 2 levels and global temperatures are correlated Current levels (360ppm) are far higher than natural levels
CO 2 levels and mean global temperature have increased faster since the Industrial Revolution Climate change scientists agree heating is largely due to human induced increases in greenhouse gas concentrations
Changes in temperature over the last 30 years
Changes in precipitation over the last 100 years
Snow, ice and hydrological change 1979 2003
Snow, ice and hydrological change Grinnell Glacier 1938 1981 1995 2005 Glacier National Park glaciers decline by 70% - gone by 2020 Mount Kenya and Kilimanjaro - decline by 60% Swiss Alps - decline by 40% since 1850 - gone by 2050?
Changes in sea level over the last 100 years
Feedback loops The surface ocean has absorbed nearly half of the increased CO 2 levels due to the burning of fossil fuels The ocean is becoming more acidic 0.1 ph unit since 1750 Continued acidification will reduce the ability of the ocean to take up CO 2
Feedback loops Permafrost soils act as a giant carbon sink approx. 1000 billion tons of Carbon Warming will thaw the tundra Melting permafrost will release frozen methane and allow decomposition of frozen plant material The additional CH4 and CO2 will increase warming
Feedback loops Warming will melt sea ice and promote growth of shrubs in the arctic Puddles and shrubs have different albedo (reflectance) than ice and tundra Puddles and shrubs will warm up rather than reflect UV Warm puddles and shrubs will increase ice melt and further shrubification
C0 2 emissions will rise at least until 2040 All scenarios predict C0 2 levels will continue to rise until the turn of the century
Predicted global temperature and sea levels
So IPCC predicts a rise in temp of 2 to 6.4 C by 2100 Bob Watson (Chair IPCC) the world should prepare for 4C of warming What happens if the world warms by 4C?
What happened the last time? 55 million years ago Palaeocene-Eocene Thermal Event 5-6C increase Tropical forests in ice free polar regions Acidified oceans led to vast die-off Sea levels rose 100m higher than todays Desert from South Africa to Europe
What happens if the world warms by 4C? India Bangladesh Pakistan shorter fierce asian monsoon drought swus, Central America, China, South America dried rivers and exhasution of aquifers deglaciation lack of freshwater Canada/Siberia - reliable precipitation - shelter and food for the world?