James Hansen former NASA scientist, considered the father of catastrophic man-made global warming awareness, Robert Hargraves, physicist, leader for thorium energy and scientist-advocate for fossil fuel caused global warming: Climate has always been changing, but humans are now the principal driver of climate change, overwhelming natural climate variability. Rising atmospheric CO2 levels, primarily a result of fossil fuel emissions, have become the predominate cause of continuing climate change. Increasing CO2 is now responsible for about 80 percent of the annual increase in climate forcing by greenhouse gases. Climate science shows unambiguously that global fossil fuel emissions must decrease rapidly over the next few decades, if we are to avoid climate calamities. The Paris Agreement. Negotiators seemed optimistic, even self-congratulatory, upon reaching the 2015 Paris Agreement. But the truth is that the accord does little to change the world’s energy and climate trajectory.