Year 2100.
Greenland glaciers have already melted, and Amazon rainforests and coral reef communities have disappeared. Peatlands in Malysia and Indonesia are burned. As places become uninhabitable in low latitudes, the amount of crops cultivated is also sharply reduced, and the fight for food is not ceased. Nearly 3 million people died from famine, 170 million people were affected by coastal flooding, and nearly 50% of species became extinct. The “tipping point” to reverse global warming has already passed. When the permafrost, even the Arctic and Antarctic, completely melts and releases massive amounts of methane, a mass extinction will soon begin.
This is a scenario where the Earth's temperature has risen by 3 degrees Celsius compared to the pre-industrial level of 1880. In its 2020 Emission Gap Report, the United Nations Environment Program (UNEP) predicts that “if the current trend continues, global temperature will rise by 3.2 degrees Celsius before 2100.”
It is observed that the current global average temperature has risen by 1.2 degrees above the reference value. Previously, scientists predicted that extreme weather events such as heat waves, heavy rains, droughts and extreme cold will become frequent around the world if global warming progresses by 1 degree. In fact, abnormal climates are frequently occurring around 2017, when the temperature exceeds 1 degree Celsius. In this summer alone, wildfires continued in North America due to heatwaves of 40-50 degrees Celsius, and in Western Europe and central China, the highest level of rainfall since meteorological observations fell at once, causing great casualties. The Middle East is experiencing drought with a heat wave of 50 degrees Celsius. Protests are taking place in Iran because of the drought.
“The target for 2100 is 1.5 degrees, which will come in 9 years.”
The occurrence of such abnormal climates is expected to become more frequent. According to a study published in 'Nature Climate Change' in 2015 by Erich Fischer, a professor at the Swiss Federal Institute of Technology, extreme weather was already becoming more frequent even when the temperature was 0.85 degrees higher than the reference level. Professor Fisher predicted, "The heat wave will double when it rises to 1.5 degrees (compared to 2015), and when it rises to 2 degrees, it will double compared to 1.5 degrees."
Even the tipping point (a point in which a phenomenon progresses slowly and causes explosive changes), at which global warming becomes irreversible, is approaching. According to the predictions of scientists this year, it will reach 1.5 degrees Celsius in 2030, just nine years later. 1.5 degrees is the current target for humankind not to exceed the year 2100.
At the time of the Paris Climate Agreement in 2015, countries set 2 degrees as the ‘Maginot Line’ by 2100, and then adjusted the target to 1.5 degrees from the 48th IPCC General Assembly held in Incheon in 2018. A report titled 'Global Warming of 1.5 degrees' was released, which states that even 2 degrees is dangerous. Scientists have predicted that the tipping point at which global warming will become irreversible will be somewhere between 1.5 and 2 degrees Celsius. There are also claims that the tipping point has already passed. In 2019, in the scientific journal Nature, a paper was published that there is evidence that the tipping point is between 1 and 2 degrees. "We are witnessing irreversible change," said lead researcher Tim Renton, a professor at the University of Exeter in the UK, in an interview with The Guardian.
According to a draft of an unpublished IPCC report obtained by AFP and reported in June, it is predicted that if 1.5 degrees Celsius continues for a long time, irreversible results can occur.
Even if the global average temperature rise exceeds 1.5 degrees, changes will come in the environment that existing living things cannot adapt to. Coral reefs, an ecosystem on which 500 million people depend, will disappear, and the Arctic will no longer be inhabitable. Fires and heavy rains caused by heat waves occur on a scale and frequency that cannot be compared with the present. 350 million city dwellers are exposed to water shortages due to drought.
“We expect 2 degrees in 2050… Permafrost methane leak possible”
According to AFP, the IPCC expects to reach 2 degrees by 2050. The crop growing system collapses, leaving tens of millions of people facing chronic starvation, and coastal cities are at risk of becoming uninhabitable. 410 million people in the city are facing water shortage. 420 million people are also expected to be exposed to extreme heatwaves. As the glaciers in Greenland and western Antarctica melt, sea levels rise by 13 meters. The melting of permafrost in Siberia, one of the most feared scenarios for scientists, could lead to the release of billions of tons of methane. Methane is a greenhouse gas 30 times more powerful than carbon dioxide, and a massive leak of methane accelerates temperature rise.
There are also more bleak prospects. In May, the World Meteorological Organization (WMO) announced that there is a 40% chance that the temperature will exceed 1.5 degrees Celsius by 2026, five years later. The United Nations (UN) also cited scientists' warnings that "Antarctic ice and Arctic sea ice is rapidly shrinking, and the Arctic permafrost has already begun to melt, releasing methane gas." Mark Linus, in his book 『The Extinction of Six Degrees』 (2014), writes that when the earth's temperature rises by six degrees, methane hydrate (a solid energy source also called 'burning ice', estimated to contain 300 times the amount of methane gas in the atmosphere) is released in large quantities, and all It has been predicted that the organism will be in a state of mass extinction.
“South Korea also needs additional measures”
The reason why major countries such as Korea, the United States, and China have set the goal of “zero greenhouse gas by 2050” came from this background. However, scientists agree that "the current response cannot prevent the Earth's temperature from going on a path that rises by 3 to 4 degrees Celsius." UNEP has set the deadline for 2030. “If significant (greenhouse gas emissions) reductions by 2030 fail, it will be difficult to achieve the goal of limiting global warming to below 1.5 degrees Celsius.” He also pointed out that advanced countries, including Korea, need additional measures beyond the current policy.