• climate → average weather over long period of time
• atmosphere → layer of gases (CO2, Methane, etc) , Co2 makes up 0.03% of atosphere
• rate of temp rise since 1975 → 20x faster
• 25% species threatened by extinction
• greenhouse gas effect: solar radiation from sun, some radiated back, some absorbed by earth, some by gases which send back to earth
• GHGs released when fossil fuels burnt
• change in temp from 1900s-2000s → 1.2 degree C
• at the point we’re at → it’s unrealistic to aim at repairing the damage we have done to the planet, at least in the next hundred years
• mitigation → target root cause (less expensive)
• vs adaptation → adjust to climate change (expensive)
• aim to limit global warming to 1.5 °C → at most 2 °C
  • difference between 1.5 and 2 is massive

For humans

For other species

• less wealthy countries
  • are the least able to afford adaptation methods
  • have contributed the least to the problem in the first place
  • suffer the most from climate change

Scale of the challenge

• in 2019, humans released an estimated 59 gigatonnes of greenhouse gases into the atmosphere
  • cities → responsible for 70% of these emissions