Original article (in Serbian) was published on 27/11/2022
At the beginning of this week, in the show “Aktuelnosti” on television with the national frequency Happy, the established topics were discussed – the war in Ukraine, geopolitics, the position of Serbia in the world… However, in addition to the many reports that concerned the war and geopolitics, a part of the speech by Australian senator Malcolm Roberts was also shown, in which he expresses completely unfounded views on climate change and denies the influence of humanity on the level of carbon dioxide in the atmosphere.
Although the guests of “Aktuelnosti” – convicted war criminal Dragan Vasiljkovic (Captain Dragan), political scientist Ivana Stojanovic and historian Dr. Jovan Janjic – did not pay too much attention to the speech of the Australian senator, attention should be drawn to Roberts’ unscientific views, who has long been known for spreading disinformation about climate change (1, 2). Roberts is a member of the extreme right-wing populist party One nation, which has two senators in the Federal Parliament of Australia and is the head of the Galileo movement, which advocates pseudoscientific theories about global warming and climate change.
Roberts: “The level of carbon dioxide is controlled by nature”
In the aforementioned report, Roberts says that “those who understand science understand that it is fundamental: humans do not and cannot affect the level of carbon dioxide in the atmosphere; it is completely controlled by nature”. He derives this conclusion from the fact that during the global crises of 2009 (financial) and 2020 (pandemic), humanity managed to reduce the emission of carbon dioxide into the atmosphere, but despite this, the level of this gas in the atmosphere continued to rise.
Although it is also true that during the years 2009 and 2020, humanity reduced the release of carbon dioxide into the atmosphere (1), but despite this, the level of this compound in the atmosphere did not decrease during the mentioned years, Roberts’ conclusion that humans do not affect the level of carbon dioxide in the atmosphere still cannot be considered accurate. This is proven by many scientific studies (1, 2, 3…) as well as climate change experts around the world, and Syukuro Manabe, a scientist from Princeton University in the United States, received the Nobel Prize for Physics last year, among other things, for proving the impact of carbon dioxide to global warming.
Vladimir Djurdjevic: The answer lies in the lifetime of carbon dioxide
Among the scientists who tirelessly draw attention to the influence of man on the level of carbon dioxide in the atmosphere is a full professor of the Faculty of Physics in Belgrade Dr. Vladimir Djurdjevic, who told FN Tragac that the answer to the question of why the level of carbon dioxide in the atmosphere did not decrease during the crisis years when we released less of this gas into the atmosphere, lies in its lifespan.
“The answer lies in the time it takes to naturally remove the carbon dioxide emitted/added to the atmosphere by humans. Different gases emitted by humans have different lifetimes. For example, methane has a lifetime of 12 years, so if we emit some amount of methane this year and then stop emitting it, the amount we added will ‘decompose’ after 12 years. The methane concentration will return to the level it was 12 years ago. Every year, the concentration will be lower and lower, until it returns to the ‘old’ value”, explains Dr. Djurdjevic.
When we talk about carbon dioxide, the circumstances are much more difficult because, according to Dr. Djurdjevic, its lifespan is significantly longer than that of methane.
“The lifetime of carbon dioxide emitted into the atmosphere is very long, from several centuries to several thousand years, and a significant part of the emitted carbon dioxide will remain in the atmosphere ‘forever’”, says Dr. Djurdjevic and draws attention to an article from the scientific journal Nature which states that “the lifetime of carbon dioxide released by burning fossil fuels into the atmosphere is several centuries, plus the 25% that essentially stays there forever”.
“If during a certain year we emit a certain amount of carbon dioxide into the atmosphere and thereby increase the concentration, and then we stop emitting it, in order to see that the concentration starts to return to the old being, it takes several centuries; in order to see the concentration that was before emitting, we will have to wait a very long time, measured in human lives forever. This is why – when we emit less carbon dioxide in one year – its concentration does not decrease, but only increases less compared to the previous year”, explains Dr. Djudjevic.
He also notes that it is precisely this property of carbon dioxide that is responsible for the climate changes we are facing being so dangerous. “There is no turning back, when we stop emitting carbon dioxide, we will simply stop there, that is, we will remain at the level of the ‘problem’ we are at that moment”, warns Dr. Djurdjevic.
