GLOBAL WARMING © 2016 Paul Billiet ODWS

Is it really getting warmer? 1979 2003 © 2016 Paul Billiet ODWS

The melting Arctic ice The length of the melt season inferred from surface temperature weekly data has been increasing by 9, 12, 12, and 17 days per decade in sea ice covered areas © 2016 Paul Billiet ODWS

The oceanic conveyor belt © 2016 Paul Billiet ODWS

The consequences Sea level rise Flooding coastal areas Reduced agricultural land Displacement of populations Climate change Displacement of ecosystems Change in range of insect vectors of pathogens Reduced biodiversity. © 2016 Paul Billiet ODWS

The consequences Increased rates of photosynthesis Increased agricultural production at high latitudes BUT faster growth means: less protein in cereals trees taller are more exposed to storm damage. © 2016 Paul Billiet ODWS

Knock-on effects Increased temperature melts the permafrost Frozen plant remains decompose More methane released Similarly soils will lose organic carbon (humus) more rapidly in a warmer climate Ice caps melt more sea exposed Snow reflects light (high albedo) Water absorbs light, increases warming More CO2 dissolving in water lowers pH Currently this is buffered and remains stable Eventually pH will drop sea life will die CO2 produced as organisms decompose. © 2016 Paul Billiet ODWS

Methanogens Methanogens are anaerobic bacteria that produce methane gas They can be used as sources of biogas gas, renewable energy source. ucla genomics © 2016 Paul Billiet ODWS

Methanogens and the greenhouse effect 50% of methane produced is used up as energy by other bacteria 50% is lost to the atmosphere (600 M tonnes y-1) where it acts as an important greenhouse gas More rice paddy fields and pasture for grazing animals = more methane produced. DAF Shiga Pref. © 2016 Paul Billiet ODWS

Warming up the brew As global warming progresses the permafrost will thaw in the regions covered by tundra Tundra contains extensive reserves of frozen peat As the peat warms and melts, it will provide a source of material for methanogens. © 2016 Paul Billiet ODWS

The knock on effect The amount of methane release into the atmosphere will accelerate This in turn will drive global warming even further Peatlands form 20-30% of organic C in N. Hemisphere. UNEP © 2016 Paul Billiet ODWS

Is it really true? Climate change skeptics The climate has changed before It’s the Sun It is not that bad There is no consensus It is cooling Models are unreliable The temperature record is unreliable Animals and plants can adapt It has not warmed since 1998 Antarctica is gaining ice Ice age predicted in 1970s CO2 rise lags temperature © 2016 Paul Billiet ODWS

What can be done? Reduce carbon emissions Improve mass transport systems (public transport) Design more efficient motors Design alternative power sources Hydrogen powered motors BUT problems of fuel reservoir, delivery, fabrication Renewable energy (wind, tidal, hydro, geothermal, biomass) BUT growing crops for biofuel reduces farmland available for food Hydroelectric dams disrupt river ecosystems Nuclear power BUT problems of nuclear waste treatment/storage. © 2016 Paul Billiet ODWS

What can be done? Increase natural CO2 sequestering Reduce deforestation Increase reforestation Reforestation Peru © 2016 Paul Billiet ODWS

What can be done? Artificial CO2 sequestering Filter CO2 sources using hydroxide scrubbers Injection of CO2 into deep ocean layers Forms CO2 reservoirs Impact on sea life unknown Injecting CO2 into disused oil wells Mineral deposition as carbonates. © 2016 Paul Billiet ODWS

Artificial CO2 sequestering © 2016 Paul Billiet ODWS

The bottom line Two factors will ultimately govern what happens: 1. Human population growth More people means greater demand for non-renewable resources 2. The ecological footprint of each individual human Higher standards of living usually means higher consumption of fossil fuels The planet will look after itself in the end There are plenty of examples where human communities have disappeared because they outstripped the environmental resources. © 2016 Paul Billiet ODWS

The planet will look after itself in the end Rapanui (Easter Island) in the Pacific Settled between AD900 and 1200 Community in severe decline AD 1700 Cause: excessive deforestation © 2016 Paul Billiet ODWS

The planet will look after itself in the end Chaco Canyon, New Mexico Anasazi culture AD 850 – 1250 Cause: Deforestation combined with a decline in rainfall © 2016 Paul Billiet ODWS

The planet will look after itself in the end Mesopotamia Sumerian civilization 3100 – 1200 BC Increased salt levels in soil due to irrigation systems & arid environment Reduced food yield © 2016 Paul Billiet ODWS

The planet will look after itself in the end Greenland Viking colony AD982 – 1350 Cause: Deforestation, soil degradation & cooling of the climate © 2016 Paul Billiet ODWS

Who’s next? © 2016 Paul Billiet ODWS forumpolitics.com/pics/earth-photo.jpg © 2016 Paul Billiet ODWS