The study also shows that if the world releases nothing today, there is only a 2% chance of violating the higher, more stringent, 2 degrees Celsius warming threshold. But that too is much more likely than if the world weren’t — 66% — Wait another 35 years for emissions to reach zero.
Today, when emissions reach zero, temperatures peak within 10 years and slowly decline as long as the concentration of greenhouse gases in the atmosphere remains low, so long and slow cooling after that peak. The period will continue. ..
According to the survey, “Future warming is dominated by future emissions, not past emissions, so societies are dominated by global warming levels before they reach major global warming levels. We do not geologically promise to exceed. ”
The findings send both a calm message that the world needs to promote the goal of reaching net zero, where greenhouse gases are emitted as little as possible, and a message that the rest will be offset.But it also sends a hopeful message: there is still a good chance to continue to curb the climate crisis. If Significantly and sustainably reduce emissions. And the sooner the better.
What this study has taught me is that the opportunity to reduce emissions to avoid temporarily exceeding 1.5 degrees is rapidly closing, “said the study’s co-author, the University of Washington. Kyle C. Armor, an associate professor of oceanography and atmospheric science at the University of Washington, told CNN. “we have to [slash emissions] Almost immediately. ”
Armor believes that focusing on limiting 1.5 degrees Celsius as a policy goal may no longer be “realistic”, and the world has a better shot by dealing with 2 degrees Celsius. I add that there is.
“That’s my personal view, because the window of opportunity is very short — and that really has to happen in the last decade,” he said. “Reducing emissions to zero is not practical on a global scale. On the contrary, keeping global warming close to or below two degrees is very difficult to understand because it takes decades to understand. I’m optimistic. ”
This includes the highly fragile ecosystems of the Arctic, mountainous and coastal areas. For example, melting ice sheets and glaciers accelerates sea level rise. Forests, peatlands, and permafrost (where greenhouse gases are naturally absorbed and stored) are also at risk of becoming emitters, leading to much warming.
With a warming of 2 ° C, 18% of all terrestrial species are endangered. According to the IPCC, for humans, as many as 3 billion people around the world will experience chronic water shortages.
The world is already at least 1.1 degrees Celsius warmer than pre-industrial levels.
The scientists who wrote this study used climate modeling to estimate changes in the Earth’s temperature in various scenarios, with emissions reduced to zero in 2021 and each year until 2080. To learn in detail about net zero modelling you need to read the complete article for a better understanding.
Researchers have also taken into account the role of various greenhouse gases and their concentration in the atmosphere, as well as aerosol and ozone depletion. While fossil fuel combustion is the main driver of climate change, aerosols (small particles of air pollution released) It is not enough to counteract the negative effects of the use of coal, oil and gas, but it also has a cooling effect.
Much of the global focus has been on reducing carbon dioxide (CO2) emissions, which are important for ending the climate crisis, but Armor said the solution is the greenhouse gases methane and aerosols.
“These aerosols are now obscuring the warming, as it tackles a few tenths of the warming when it is lost,” he said. “That is, if we continue to emit, we are geologically working on these temperature levels, such as 1.5 degrees and 2 degrees, about 5-10 years before we actually reach these levels. Please continue to contaminate the aerosol. ”
Kim Cobb, director of the Georgia Institute of Technology’s Global Change Program, said the study proves that it is important to understand the evolution of different types of emissions.
“As for our ability to predict the timing and magnitude of peak warming, this paper shows that the devil is in detail,” Cobb, who was not involved in the study, told CNN. “It may look pretty’in the weeds’, but when talking about a few tenths of a Celsius, it’s a big problem from a global warming level perspective. ”
Cobb said the latest research is not only based on existing climate research, but emphasizes that many in the scientific community already knew it was true.
“There are only a few years to reduce emissions because of the desire to limit global warming to 1.5 degrees Celsius,” Cobb said. “This opportunity slips through our fingers as the years of doing nothing increase.”