A group of scientists has warned the world's governments about the increasing threat of greenhouse gases and said if changes are not made the planet will enter a permanent "hothouse" state.
In a study published in the multidisciplinary scientific journal Proceedings of the National Academy of Sciences of the United States of America (PNAS), a group of scientists "explore the risk that self-reinforcing feedbacks could push the Earth System toward a planetary threshold that, if crossed, could prevent stabilization of the climate at intermediate temperature rises."
The planet has a stabilization system, composed of different natural elements which absorb CO2. Oceans, lands, forests and the polar ice absorb millions of tons of carbon every year. These are today our allies in the fight against global warming. However, scientists are warning that if the planet crosses the threshold, it could disrupt the stabilization mechanisms, which would "cause continued warming on a “Hothouse Earth” pathway even as human emissions are reduced."
The mechanisms that capture carbon particles can change their structures, due to the temperature rise, and as a consequence could start ejecting the absorbed particles into the atmosphere. "These tipping elements can potentially act like a row of dominoes. Once one is pushed over, it pushes Earth towards another," explained Johan Rockstrom, executive director of the Stockholm Resilience Center and one of the authors of the report.
"Crossing the threshold would lead to a much higher global average temperature than any interglacial in the past 1.2 million years and to sea levels significantly higher than at any time in the Holocene," the report said, explaining this could lead to a drastic change in life on the planet.
Sea levels would rise, storms could become stronger, some coral reefs would be eliminated, and some rivers would flood more frequently, the report warns. The condition "guarantees a climate 4-5 Celsius (7-9 Fahrenheit) higher than pre-industrial times, and sea levels that are 10 to 60 meters (30-200 feet) high than today," the article warns.
The scientists said "collective human action is required to steer the Earth System away from the potential threshold... Such action entails stewardship of the entire Earth System—biosphere, climate, and societies—and could include decarbonization of the global economy, enhancement of biosphere carbon sinks, behavioral changes, technological innovations, new governance arrangements, and transformed social values."
If actions are not taken, crossing this threshold could happen by the end of this century, they explained.