Understanding our changing global climate April 20, 2018 Stephen Po-Chedley Andrea Fassbender greenhouse warming is not a new idea. Joseph Fourier (1820s) about -70oF about 57oF John Tyndall (1850s) carbon dioxide o 2xCO2 = 10 F warming Svante Arrhenius (1900s) …human beings are now carrying out a large scale geophysical experiment of a kind that could not have happened in the past nor be reproduced in the future… Within a few centuries we are returning to the atmosphere and oceans the concentrated organic carbon stored in sedimentary rocks over hundreds of millions of years… This experiment, if adequately documented, may yield a far-reaching insight into the processes determining weather and climate… Revelle and Suess (1957) *28% 88% 44% * 12% 6% 22% Le Quéré et al., 2017 - ESSD Scripps Institute of Oceanography greenhouse warming is not a new idea. we see climate change everywhere we look. Temperature difference compared to 1965 Berkeley Earth Temperature Data F) o 2.0 - - 1.0 - - 0.0 - Global Temperature Change ( Temperature Global - Penn State / Michael Mann / IPCC from: Dyurgerov and Meier (2005) National Climate Assessment National Climate Assessment greenhouse warming is not a new idea. we see climate change everywhere we look. it isn’t controversial. percent that think global warming is happening 69% 50% R / 82% D percent that think global warming is mostly caused by human activities 52% 31% R / 65% D percent that trust scientists about global warming 70% 97% of climate scientists agree that climate change is happening and that humans are the dominant driver of observed climate change e.g., Anderegg et al. (2010) percent that think that most scientists agree global warming is happening 48% 33% R / 64% D percent that think global warming is mostly caused by human activities Democrats 65% a politicized issue Republicans 31% The lead attorney for oil giant Chevron, meanwhile, quickly declared the company is convinced humans are playing a major role in climate change—a split from some fossil fuel advocates, including top officials in President Donald Trump’s administration. “From Chevron’s perspective there’s no debate about climate science,” said attorney Theodore Boutrous Jr. Science Magazine percent that want to regulate carbon dioxide 74% 57% R / 85% D greenhouse warming is not a new idea. we see climate change everywhere we look. it isn’t controversial. we can estimate future changes in climate. Syukuro Manabe (1970s) Modern climate models typically James Hansen (1980s) predict a 5oF temperature rise for a doubling of CO2. Ruddiman (2001) National Climate Assessment oF 4.0 6.0 8.0 Adapted from IPCC AR5 South Bay Climate Evolution South Bay Climate Evolution South Bay Cooling South Bay Projected Temperature Change 1979 - 2018 South Bay Rapid Warming oF per decade greenhouse warming is not a new idea. we see climate change everywhere we look. it isn’t controversial. we can estimate future changes in climate. climate change has important impacts. Year 2100 (business as usual) Shirzaei et al. (2017), BAMS Atmospheric CO2 Ocean CO2 Ocean pH National Climate Assessment Extreme fire danger days no climate change with climate change Yoon et al. (2017), BAMS John Burgess (Press Democrat) California Climate Adaptation Strategy (2009)StrategyAdaptation Climate California AP (2017) SF Gate (2017) Time (2014) yield changes in California central valley. National Climate Assessment Joel Ertola (TIME) greenhouse warming is not a new idea. we see climate change everywhere we look. it isn’t controversial. we can estimate future changes in climate. climate change has important impacts. we have choices to make. Key Points • Keep warming “well below 2o Celsius” [3.6oF] • Strive to stay below 1.5o Celsius [2.7oF] South Bay Climate Evolution California Wikipedia 1. The US economy grew while emissions fell 2. Corporations are voluntarily reducing emissions 3. Clean energy prices are rapidly falling and states are committed to using renewables 4. There is global momentum to reduce greenhouse gas emissions greenhouse warming is not a new idea. we see climate change everywhere we look. it isn’t controversial. we can estimate future changes in climate. climate change has important impacts. we have choices to make. you can make a difference. reduce water use Talk about Advocate for climate change pricing carbon as a priority pollution Make climate an important part of your vote greenhouse warming is not a new idea. we see climate change everywhere we look. it isn’t controversial. we can estimate future changes in climate. climate change has important impacts. we have choices to make. you can make a difference. from: cs4s.net With human influence Natural factors National Climate Assessment njhealth.org per capita emissions climate vulnerability Samson et al (2011) Make climate a voting issue Manabe and Stouffer (2017) National Climate Assessment .