1. Obama, Trump, and the Climate Challenge
President Obama made actions on climate change a priority in his presidency
But Affordable Healthcare Act (Obamacare) took precedent over climate change in when Democrats controlled Congress
Copenhagen climate summit in 2009 did not resolve the problem of China and India taking actions on climate
Obama’s push for “new energy economy”—clean energy and energy efficiency—plus the surge in oil from fracking and natural gas led to American self-sufficiency in energy

2. China, Paris, to Trump
2014, Obama and Chinese president Xi Jinping reached agreement that the US would lower its greenhouse gas emission from its 2005 level by about 26-28% by 2025 and China would reach its greenhouse gas emission by 2030
2015: US-China agreement paved the way for the global climate change agreement in Paris
2016: Donald Trump, who doubted the reality of anthropogenic climate change, won presidential election
2017: President Trump withdrew the US from the Paris agreement but many states and localities, including California and Cal Poly Pomona have defied the White House and decided to stay with Paris Agreement