In December 2015, the world's nations negotiated the Paris Climate Agreement, which seeks to limit global warming to a maximum of 2 degrees Celsius above pre-industrial temperatures. Scientists at the University of Maryland have developed an empirical model of global climate, which they have used to comprehensively analyze the Paris Agreement.
In a new book titled Paris Climate Agreement: Beacon of Hope, the authors describe their findings. They suggest that if countries achieve the greenhouse gas reductions pledged during the Paris meeting, there is a good chance that the world will be able to limit warming to 2 degrees Celsius.
Climate models that forecast global warming use one of four numbered scenarios to describe greenhouse gases in the future atmosphere. Researchers refer to these projections as representative concentration pathway (RCP) scenarios, each of which accounts for the influence of greenhouse gases and other pollutants on climate up to the year 2100. RCP 4.5, one of the more optimistic pathways, assumes that human emissions of greenhouse gases will level off soon and then decline after a few decades. The authors are convinced, that if the world keeps emissions to RCP 4.5, we will almost certainly stay beneath two degrees of global warming.
"Our research shows that if the Paris Climate Agreement is met, it will put us on the RCP 4.5 pathway, but this can only happen if two important things occur," said co-author Walter Tribett. "One, all conditional and unconditional intended nationally determined contribution (INDC) must be met. Two, the mitigation of greenhouse gases needed to meet the Paris goal must be propagated out to 2060." Each INDC is different, based on the status and needs of each country. But most recognize the importance of non-emitting, renewable sources of energy.
To achieve the goals, half of the world's global energy must come from renewable sources by 2060. This is an ambitious goal that requires a large-scale global transition to renewable energy. The book's authors suggest that the developing world will have a great need for renewable energy solutions. But the developed world has a large role to play as well.
"This will require large-scale transfer of technology and capital from the developed to the developing world," noted Ross Salawitch, who is professor at the UMD's Earth System Science Interdisciplinary Center. "And at the same time, the developed world must reduce its own dependence on fossil fuels--not a little bit, but massively--by 2060."
R. Salawitch, T. Canty, A. Hope, W. Tribett, B. Bennett
Paris Climate Agreement: Beacon of Hope
2017, 186 p. 54 illus. in color