Sea Level Rises Will Challenge Humanity's Resilience

A groundbreaking study has revealed that rising sea levels will pose severe challenges for humanity in the latter half of the 21st century, even if the ambitious global warming limit of 1.5 degrees Celsius is achieved. Researchers warn that the current pace of ocean rise has doubled in the last 30 years and is projected to double again by 2100, potentially reaching alarming rates of 1 cm per year.

Cutting Emissions Alone May Not Be Enough

Lead researcher Chris Stokes from Durham University stated, "Capping global warming at 1.5°C would indeed be an impressive feat, helping to avert many catastrophic climate impacts. However, even if we meet this goal, sea level rise is anticipated to accelerate to levels that will be incredibly hard to adapt to." Without protective infrastructure, such as sea walls, a mere 20 cm rise by 2050 could lead to an astonishing $1 trillion in flood damages annually in the world's 136 largest coastal cities.

The Number of Lives at Stake

Currently, approximately 230 million people dwell on land just one meter above sea level, and over a billion live within 10 meters. This statistic underscores the urgent need for immediate action to safeguard these populations against impending coastal disasters.

Drivers of Sea Level Rise

The alarming rise in sea levels is a result of multiple factors: the melting of ice sheets and glaciers, combined with the expansion of warming oceans that absorb over 90 percent of excess heat from climate change. Presently, Earth's surface temperature is 1.2°C above pre-industrial levels, which is enough to raise ocean levels significantly in the coming centuries.

Revisiting Tipping Points

A thorough review of recent scientific literature since the last major UN climate assessment has shed light on the troubling contributions of ice sheets to rising sea levels. The Intergovernmental Panel on Climate Change (IPCC) estimated sea levels could rise between 40 to 80 centimeters by 2100. However, new findings suggest we may be approaching the higher end of this range.

Research Findings Upset Previous Understandings

Recent satellite data has unveiled that ice sheets containing enough frozen water to elevate sea levels by 65 m are more sensitive to climate change than previously thought. The amount of ice melting or calving off from Greenland and West Antarctica has quadrupled over the past three decades, significantly outpacing the contributions from mountain glaciers.

Historical Climate Insights Reveal Alarming Patterns

Past warm periods in Earth's history reveal worrisome trends. For instance, 125,000 years ago during the last interglacial period, sea levels were 2 to 9 meters higher than today, despite lower average global temperatures. The study underscores that if immediate steps aren't taken to cool global temperatures, we could witness sea levels rising to levels last seen three million years ago where they were 10 to 20 meters higher.

What Can Be Done to Mitigate the Crisis?

Stokes emphasizes that to stabilize sea level rise from ice sheets, significant cooling of the current temperatures is essential. He states that to achieve manageable sea levels, we need to aim for a long-term temperature goal well below current levels, ideally close to 1°C or even lower.