A sobering report released by the Intergovernmental Panel on Climate Change in October 2018 highlighted the importance of keeping global warming below 1.5°C above pre-industrial levels. Today, average temperatures have already risen by about 1.0°C.
The difference in the expected outcomes of between a 1.5°C increase and 2.0°C, according to the IPCC, could be extreme, with the latter resulting in significantly more ice loss, sea level rise, species extinction, and severe changes in weather. However, even keeping global temperatures from rising by no more than 2.0°C will likely be a serious challenge for the global community.
Climate scientists agree that global carbon emissions will largely impact climate change. They project different scenarios depending on the amount and rate at which emissions will fall, remain the same, or increase. The “business-as-usual” scenario, referred to as RCP 8.5, considers no change in the world’s greenhouse gases emissions. Under this scenario, some estimate temperatures would rise by over 4.0°C over pre-industrial levels by the end of the century. Some anticipate even higher temperature increases.
In an interview with 24/7 Wall St., Ken Caldeira, a climate scientist working for the Carnegie Institution for Science’s Department of Global Ecology at Stanford University, told 24/7 Wall St. that while there are too many factors at play to confidently predict a single outcome, he views RCP 8.5 as the most likely scenario.
24/7 Wall St. consulted reports by groups such as the IPCC, NASA, the National Oceanographic and Atmospheric Association, the U.S. Global Change Research Program, and more to identify the potential effects of global climate change on the Earth and its inhabitants. Many of these predictions are based on average global temperature increases of at least 4°C above pre-industrial levels by 2100.