Adelie penguins stand atop ice near the French station at Dumont díUrville in East Antarctica, Jan. 22, 2010. REUTERS/Pauline Askin

Sea levels are rising and one of the biggest questions researchers have about it is how fast it will happen. In other words, at what point will the world’s coastlines and some major cities start to flood.

But a new study published Thursday predicts that if a global coal phase out is completed by 2050 the sea rise might stay limited to 50 cm or about 19 inches.

The issue however, is what will happen if coal is not phased out, completely or at all before 2050. The countries that have committed to the Paris Climate Agreement have agreed to work toward keeping global temperature rise at just two degrees Celcius, or 3.6 degrees Fahrenheit, before the turn of the century. If this goal is achieved, potentially catastrophic flooding might be avoided.

What sets the new study apart from past studies is that it focuses on more than solely sea ice melt in the Antarctic or other isolated contributors to sea level rise while this study examines multiple factors at once to form a comprehensive view. The introduction of the study explains that one of the key aspects of the research was examine “shared socioeconomic pathways” meaning to look combined societal factors in sea level rise as well as “physical forcing pathways.”

More specifically the researchers involved in the study looked at five different SSPs to work with. Each of these SSPs has its own varying levels of socioeconomic challenges for both mitigation and adaptation in the future. That way the researchers could look at an array of climate change and sea level rise scenarios for the future to best predict possible circumstances. Each of these circumstances too into account different levels of climatological forcing as well as responses and policy adaptation from governments to predict an outcome.

“SSP-FT framework allows us to not only analyze future SLR under a wide variety of societal developments but to also clearly distinguish between SLR projections for the non-mitigation baseline scenarios and scenario sets with varying levels of climate mitigation efforts,” says the study. The results, published in the journal Environmental Research Letters predicted a large difference in sea level rise between the scenarios that included mitigation efforts in the SSPs and those that didn’t.

If carbon emissions continue as usual, and nothing is done to cute them, the study found that by 2100 sea levels could rise 132 centimeters, or more than four feet. This would put multiple cities underwater. But the study also found that strong mitigation efforts could prevent the issues caused by the sea level rise from the Antarctic ice sheet melt, those efforts would likely need to be spurred by policy changes.

The Surging Seas feature from Climate Central is a good tool for mapping areas of the world and sea level rise. It can show users what parts of the world would be underwater given a certain amount of sea level rise.