Saving CO2 today saves offspring from rising sea levels

If we were to finally take seriously the drastic reduction of greenhouse gas emissions in line with the Paris climate goals now and in the coming decades, future generations could be spared a significant portion of sea level rise. In a study published in the journal "Nature Climate Change," researchers estimate that the rise by the year 2300 would be a whopping 0.6 meters lower than if emissions continue at the current rate.

The rise in global sea level is one of the most obvious effects of human-caused global warming. In particular, the water masses stored in the large ice sheets over Greenland and Antarctica have the potential to raise ocean levels by several meters. If the Greenland ice sheet were to melt completely, it would cause sea level to rise by more than seven meters. The extent of this impact will determine how much coastlines will change, how many relatively flat islands will disappear or become uninhabitable, and which coastal cities will be able to survive in the future.

Stakes for the future already laid

The increase in CO2 levels in the atmosphere, from around 320 CO2 particles per million total particles (ppm) in the early 1960s to over 420 ppm today, will continue to be reflected in rising water levels well into the future. By comparison, in pre-industrial times, the concentration was around 280 ppm.

Since large ice masses, in particular, do not react immediately to changes, the timing and extent of sea level rise are still difficult to estimate. However, the fact that it is rising is certain and already measurable. An international team, including experts from the International Institute for Applied Systems Analysis (IIASA) in Laxenburg near Vienna, has now addressed one aspect of the problem: namely, the question of what benefit emissions alone between 2020 and 2090 will bring to future generations up to 2300.

Decisive for the next decades

If current climate policy were to remain unchanged, emissions alone would raise sea levels by around 0.3 meters between 2020 and 2050, according to calculations. This may not seem too tragic, but it would have "major implications for long-term climate change adaptation planning," according to a press release from the IIASA. If CO2 emissions continued at this rate until 2090, the resulting increase alone would be approximately 0.8 meters.

Conversely, if emissions were to be significantly reduced from now on in line with the Paris Climate Agreement, future Earth inhabitants could be spared 60 centimeters of this total 80 centimeters of increase, calculate the scientists led by Alexander Nauels from the IIASA.

The study "clearly shows that current mitigation measures and those in the coming decades will have consequences for coastal regions worldwide for several centuries," says Nauels. The participating researchers emphasize that the work proves once again that the upcoming decisions and efforts to reduce greenhouse gases will have very tangible effects on the lives of future residents in many regions of the world.

(SERVICE – https://dx.doi.org/10.1038/s41558-025-02452-5 )

APA