If all our carbon emissions were removed overnight, global temperatures could begin to drop as early as 2033, according to a study. Naturally, we will have to wait much longer. It goes without saying that if we really put in place the means necessary to reduce our greenhouse gas emissions, the impact of these measures will not be immediate. But how long should we wait before seeing a result?
A team of researchers led by Bjørn Hallvard Samset, from the Center for International Climate Research in Norway, recently asked the question. The results of their work are published in the journal Nature Communications.
Delayed effects
As part of this study, the researchers used climate models to assess how our planet could respond to different control efforts. In addition, they explored several specific types of emissions — carbon dioxide, black carbon, and methane — to determine if any of them would quickly reduce the rate of warming.
First, the study points out that there is no shortcut. In other words, focusing on one type of program rather than another would not make a real difference. Also, the researchers argue that we should focus on reducing the most important CO2 emissions.
One of these models then relied on the assumption that, from this year 2020, all of our CO2 emissions would stop. This projection, naturally impossible, allows us to appreciate the degree of response of our planet to our efforts.
In this scenario, the world would avoid warming by more than 0.7 degrees Celsius by 2100. In contrast, the first noticeable effects on global surface temperatures would not begin to be significant until 2033.
According to another slightly more realistic model, which forecasts a reduction of 5% in our CO2 emissions each year, this time we would see global warming begin to reverse significantly from the year 2044.
Avoiding confusion in the future
Naomi Goldenson of the University of California, United States, who did not work on the document, told Earther that the results were “not a surprise.” This delay in the response in terms of temperatures is in fact “inevitable” since carbon dioxide has a very long lifespan in our atmosphere.
Concretely, therefore, if we put in place real measures to mitigate global warming, the first effects of these efforts will only be visible in 20 or 30 years, at best. It is not about being pessimistic, it is about being “outspoken and realistic,” says Bjørn Hallvard Samset, and “avoiding confusion in the future.”
There is indeed a chance that we will still see a rise in temperatures for a decade, even if we put in place very strong measures before these efforts start to pay off.
