The 10 ​Science ​‘Must​ Knows’ ​on ​Climate ​Change

While selecting trustworthy sources from a seemingly endless mass of information might seem an impossible task, one thing can and should be done: defining indisputable climate facts. A handful of climatic issues enjoy extensive testing and research, and their conclusions are as reliable as it can be. Yet, decision-makers spend precious resources debating the verity of these climatic issues, resources that could be applied to furthering climate action.

In this short paper, the Earth League and Future Earth unravel 10 scientific facts on climate change that should be recognized by those pursuing the goals set by the Paris Agreement, while proposing policies to achieve them.

  1. Evidence​ ​shows​ ​that​ ​Earth​ ​has entered​ ​a​ ​new​ ​geological​ ​epoch –​​ ​the​ ​Anthropocene​ ​​–​​ ​with profound​ ​implications​ ​for humanity​ ​and​ ​the​ ​relative stability​ ​of​ ​the​ ​Earth​ ​system.
  2. ​ ​​Earth​ ​is​ ​approaching​ ​tipping points​ ​due​ ​to​ ​human​ ​pressures.
  3. Risks​ ​of​ ​extreme​ ​weather​ ​are increasing.
  4. Rising​ ​sea​ ​levels​ ​and​ ​ocean acidification​ ​are​ ​growing threats.
  5. The​ ​costs​ ​of​ ​climate​ ​change​ ​are already​ ​being​ ​felt​ ​today​ ​and​ ​will increase​ ​in​ ​the​ ​future.
  6. Human​ ​health​ ​is​ ​at​ ​risk​ ​from air​ ​pollutants​ ​that​ ​alter​ ​the climate,​ ​and​ ​the​ ​impacts​ ​of​ ​a changing​ ​climate,​ ​which​ ​are decreasing​ ​food​ ​security​ ​and increasing​ ​the​ ​risks​ ​of​ ​disease and​ ​heat​ ​stress.
  7. Climate​ ​change​ ​is​ ​likely​ ​to exacerbate​ ​the​ ​risk​ ​of large-scale​ ​migration​ ​and​ ​civil unrest.
  8. ​The​ ​world​ ​needs​ ​to​ ​act​ ​faster: deeper​ ​cuts​ ​are​ ​needed​ ​to reduce​ ​risk​ ​of​ ​global​ ​average temperature​ ​rising​ ​2​ ​°C​ ​above pre-industrial​ ​levels.​ ​A​ ​pathway of​ ​halving​ ​global​ ​emissions every​ ​decade​ ​is​ ​consistent​ ​with this​ ​goal.
  9. Analyses​ ​suggest​ ​that​ ​it​ ​is possible​ ​for​ ​the​ ​world​ ​to​ ​meet Paris​ ​Agreement​ ​targets​ ​if nation​ ​states​ ​cooperate​ ​and coordinate​ ​mitigation​ ​efforts. Carbon​ ​pricing​ ​is​ ​an important​ ​policy​ ​tool​ ​that would​ ​create​ ​substantial revenues​ ​amounting​ ​to potentially​ ​several​ ​percent​ ​of GDP.
  10. Adaptation​ ​and​ ​resilience building​ ​are​ ​necessary​ ​even​ ​if the​ ​world​ ​succeeds​ ​with aggressive​ ​international​ ​action to​ ​reduce​ ​emissions​ ​of greenhouse​ ​gases.