Even if humanity stopped emitting greenhouse gases tomorrow, the Earth would be warming for centuries and the oceans would rise by meters, according to a study of controversial modeling published on Thursday.
The natural drivers of global warming – more heat dissipating clouds, permafrost melting and sea ice shrinking – which are already accelerating by carbon pollution, will pick up speed, Norwegian researchers have reported in the journal Nature Scientific Reports.
“According to our model Dales, when it comes to stopping the melting of permafrost by using greenhouse gas cuts as a tool, humanity is out of point-of-return,” Said.
“If we want to stop this melting process, we must do something more – for example, sucking CO2 out of the atmosphere and storing it underground, and brightening the earth’s surface.”
Using the Dell Climate Model Dell, renderers and colleague Ulrich Goluk predicted change over 2500 years under two circumstances: an immediate cessation of emissions and a gradual decrease in the Earth’s temperature gases by 2100.
In a fictional world where carbon pollution stops with the flip of a switch, the planet warms up to about 3.3 degrees Celsius above pre-industry levels over the next 500 years – about half of the target set in the Paris Agreement in 2001 – and then cools slightly. Is.
When temperatures began to rise in the mid-19th century, the Earth’s surface is now more than 1.2 cm warmer.
But starting in 2150, the model will gradually begin to warm up again in the following 350 years, with temperatures rising by a second degree, and sea levels rising by at least three meters.
Under the second view, the earth heats up to a level that bursts more quickly on the fabric of the culture, but ends up at about 2500 at about the same point.
– ‘Tipping point’ –
The main finding fought by leading climate scientists is that some thresholds or “tipping points” in the Earth’s climate system have already been crossed, initiating a self-perpetuating process of warming, as has happened in the past millions of years. .
One of these drivers is the rapid retreat of sea ice in the Arctic.
Since the end of the 20th century, millions of square kilometers of ice and snow – which reflects about 80 percent of the sun’s radioactive energy into space – have been replaced by the open sea in summer, which instead absorbs an equal percentage.
Another source is the melting of permafrost, which contains twice as much carbon as it does in the atmosphere. A third proportion of water vapor is rising, which also affects the temperature.
Study-Dozens of leading climate scientists’ reactions to the study – which the authors accept to be planned – some call the findings follow-up research, and others reject it out of hand.
“The model Dell used here … does not show a reliable representation of the actual weather system,” said Richard Bates, head of climate impact research at Exeter University.
“In fact, it is in direct contrast to the more established and elaborate assessment environment by Dello.”
Mark Muslin, a professor of climatology at University College London, also pointed to the shortcomings of the model known as ESCIMO, describing the study as a “thought experiment”.
“The focus of this study is to reduce global carbon emissions to zero by 2050” – a goal adopted by the UN and a growing number of countries – “the beginning of our actions in dealing with climate change.”
UN Scientific Advisory Organization, IPCC The more sophisticated models used in the estimates also show that the Paris Climate Agreement temperature targets cannot be reached unless large amounts of CO2 are emitted from the atmosphere.
One way to do that is by planting billions of trees. Experimental techniques have shown that sucking CO2 from the air can be done mechanically, but not yet on the required scale.
MH / PG / MBX
