Climate change

• Anthropogenic climate change


  Caused by humans
• Anthropogenic climate change

  • Long term shifts in temperature and weather patterns
  • Fossil fuels increase carbon dioxide
  • Bacteria in guts of ruminants and melting permafrost increases methane
• Correlation does not imply causation (according to some people)
• Positive feedback loops and global warming

  • Loss of snow and ice - white snow reflects solar radiation, darker land exposed absorbs heat and increases global temperatures
  • Decomposition of permafrost, methane increase global temperatures
  • Carbon dioxide from ocean, less can dissolve in water, increase atmospheric greenhouse gas, increase global temperatures
  • Forest fires, increase carbon dioxide and global temperatures
• Carbon dioxide and methane are the biggest contributors to climate change
• Boreal forests and tipping points

  • Carbon sink
  • Lots of carbon is stored in the ground, low temperatures means slowed decomposition
  • Tipping point is when more carbon is released than stored
  • Increased temperatures decreases snowfall, Decreases primary production through photosynthesis
  • Forest browning due to droughts increases frequency and intensity of wildfires
• Melting of ice

  • Walruses use ice floes for resting and feeding young, must travel farther for food, more difficult to feed young, Stampedes
  • Emperor penguins use sea ice for breeding colonies, Chicks can't swim in icy water, Extinctions
• Nutrient upwelling


  Winds blow against surface water, Cold nutrient rich water rises up, Depends on wind and weather, Warm water prevents upwelling
• Poleward and upslope range shifts of temperate species

  • Birds go to higher altitudes, Upslope, Colder
  • Movement of ranges of trees, Sugar maple trees move northwards to cooler climates, Poleward
• Coral reefs


  • Most diverse ocean ecosystem
  • Carbon dioxide + water -> carbonic acid, Carbonic acid -> proton + bicarbonate, Protons makes it acidic, Proton + carbonate -> bicarbonate, Proton binds preferably to the carbonate, less available for coral exoskeletons
  • Calcium carbonate is needed for coral exoskeletons, Calcium + carbonate -> calcium carbonate
• Coral bleaching


  Becomes white and loses color, Color is due to the zooxanthellae algae, Increased temperature causes stress, algae leaves coral, Mutualistic relationship, Coral death
• Carbon sequestration

  1. Afforestation - establishing forests where there was no recent tree cover

  2. Forest regeneration - forest grows back after a disturbance

  3. Agroforestry - farmer continues while using trees, trees protect, shade and fertilize, increase decomposition and increased photosynthesis

  4. Restoration of peat forming wetlands, rewetting restores carbon levels in peat soils
• Peat formation

  Organic matter is not fully decomposed, Acidic, anaerobic, waterlogged conditions, Large carbon store
• Phenology


  Cyclic and natural phenomena in relation to climate and plant/animal life
• Photoperiod


  Length of time in a day an organism receives light
• Decreased temp and day length

  Decreases growth in deciduous trees
• Increased temp in spring


  Triggers bud burst
• Biological events

  • Flowering
  • Budburst - emergence of new leaves
  • Bud set - cessation of bud growth in deciduous plants
  • Migration
  • Nesting
• Climate change disrupts the synchrony of phenological events
• Reindeer and arctic mouse eared chickweed

  • Migration synchronized with growth, Increased temp leads to growth, global warming means earlier growth, Reindeer migration determined by photoperiod, Reduces food for reindeer
• Great tit and caterpillar biomass

  • Great tits eat caterpillars, Increased temp triggers caterpillars, photoperiod triggers great tit, Great tits hatch after caterpillars peak
• Consequences of global warming in insects

  • Increased generations
  • Expand geographic range
  • Outbreak of insect transmitted plant diseases
  • Increased overwintering survival
  • Desynchronization with natural enemies and host plant
  • Shorten life span, increase population
• Tawny owls

  • Grey or brown, Increased temp decreases snow, Brown is more likely to survive mild winters