Even in the best case scenario, sea level rise from global warming will continue through 2300, according to a new study published in Proceedings of the National Academy of Sciences.
The report found that the current rates of glacier and ice sheet melt and warming waters, combined with environmental feedback loops, have essentially locked in sea level rise of at least 1 meter by the year 2300, an amount that would flood large parts of the world and cause catastrophic harm to coastal regions.
That’s a "what-if" scenario that would require countries to adhere to the targets set under the Paris climate agreement and then completely stop releasing emissions.
The authors of the report note that greenhouse gas emissions between 1750 and 2015 will cause 80 centimeters of sea level rise. Based on current and projected levels, emissions between 2016 and 2030 will cause another 20 centimeters of sea level rise.
"Even in that 15-year interval, emissions will still cause a fairly significant increase," Peter Clark, an Oregon State University climate scientist and co-author of the study, told Global Citizen. "The bottom line is, no matter how much you emit, you commit to sea level rise."
"We’re committing to a continuous rise of sea level that people will have to continually adapt to and pay a lot of money to adapt to or just move from their homes and abandon coastal areas," he added.
For emissions to even halve by 2030, countries would have to invest trillions in solar and wind energy, shudder coal and natural gas power plants, prohibit the exploration and extraction of fossil fuels, overhaul transportation and food sectors, plant trillions of trees, and much more.
In other words, bringing emissions to zero by 2030 is not possible under the current status quo.
The more likely "business-as-usual" scenario involves steadily rising greenhouse gas emissions through 2030, and then gradually phased out emissions in the decades after, which would lead to sea level rise much greater than 1 meter by 2300.
Sea level rise in recent years has accelerated to 3 millimeters a year, a rate that could increase if emissions keep rising. Although sea level rise is a global problem, the United States, China, Russia, India, and the European Union are the primary drivers of the phenomenon.
These countries account for the vast majority of greenhouse gas emissions entering the atmosphere on an annual basis. These countries are vital to any effort to minimize sea level rise, yet their emissions show no signs of slowing.
The US, in particular, has become a major obstacle in achieving targets set under the Paris climate agreement, as the country has officially begun its withdrawal process. The US has also rolled back key environmental regulations in recent years, and has vastly increased its fossil fuel production.
Sea level rise threatens to destabilize large parts of the planet. In fact, another recent study on sea level rise shows that 150 million people could be displaced by as early as 2050.
How countries manage this displacement will influence geopolitics far into the future. Will countries adapt and create systems for assisting climate refugees, allowing for a “managed retreat” away from vulnerable coastlines? Or will countries only deal with displacement when homes and streets are flooded?
This problem will be considerably worse if countries don’t begin to transition beyond fossil fuels.
"Further emissions reductions will be needed," Clark said. "This is another way of pointing out that the pledged emissions, no matter how much, will cause sea levels to rise."
"The more we reduce emissions, the less the impact will be," he added.