Leading climate scientist Piers Forster explains what the UN’s latest study really means in a series of tweets
Observed temperature changes 1901-2012 (Pic: IPCC)
#IPCC 18 SPM headlines in tweets
— Piers Forster (@piersforster) September 27, 2013
Warming of the climate system is unequivocal, unprecedented across climate system
— Piers Forster (@piersforster) September 27, 2013
Each of last three decades getting warmer, warmest 30 years since 600 A.D
— Piers Forster (@piersforster) September 27, 2013
Ocean has absorbed 90% of energy increase, warming virtually certain since 1900
— Piers Forster (@piersforster) September 27, 2013
Greenland and Antarctic ice sheets loosing mass since 1990, as have glaciers, Arctic ice and N.H. snow
— Piers Forster (@piersforster) September 27, 2013
20 cm of sea-level rise since 1900, more than in past 2000 years
— Piers Forster (@piersforster) September 27, 2013
40% rise in CO2, since preindustrial; CO2, CH4, and N2O rise unprecedented in last 800k years
— Piers Forster (@piersforster) September 27, 2013
Total radiative forcing positive, CO2 largest contributor; energy uptake of system
— Piers Forster (@piersforster) September 27, 2013
Human influence on the climate system is clear – GHG increases, positive RF, obs warming and understanding
— Piers Forster (@piersforster) September 27, 2013
Climate models have improved, and can reproduce obs trends
— Piers Forster (@piersforster) September 27, 2013
Obs and models studies on temp change, and feedbacks, provide confidence in past and future warming
— Piers Forster (@piersforster) September 27, 2013
Human influence detected across climate system, extremely likely it is dominant cause of 20C warming
— Piers Forster (@piersforster) September 27, 2013
Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions.
— Piers Forster (@piersforster) September 27, 2013
All RCPs warm to 2100 and all but RCP2.6 warm pass 2C and will continue to warm beyond 2100
— Piers Forster (@piersforster) September 27, 2013
Wet regions generally wetter, dry drier but with exceptions
— Piers Forster (@piersforster) September 27, 2013
The ocean will warm during the 21C. Heat will penetrate to the deep ocean and affect circulation
— Piers Forster (@piersforster) September 27, 2013
Arctic sea-ice, glaciers and snow will continue to shrink as temperatures rise
— Piers Forster (@piersforster) September 27, 2013
Sea level will continue to rise during 21C and accelerate
— Piers Forster (@piersforster) September 27, 2013
Carbon cycle process will exacerbate climate change
— Piers Forster (@piersforster) September 27, 2013
Change will persist for many centuries even if emissions stopped. Multi century commitment
— Piers Forster (@piersforster) September 27, 2013