Global warming. Climate change. Climate crisis. Various definitions arrived at step by step, as the scientific community continued to produce unequivocal data on the phenomena underway. Numbers and trends that have helped build unanimous consensus – on the part of the scientific community itself – on the link between human activities and global warming. And yet, there are those who continue to cast doubt on climate change. "But these are personal positions that absolutely do not fall within the sphere of scientific consensus," points out Serena Giacomin, climatologist and president of Italian Climate Network, the Italian climate movement; a lecturer and management consultant specialising in climate risk, Giacomin presents weather segments on TV and on the major national radio stations.

The climate is changing because of us – there is no doubt

Having worked on these issues for years, she has heard plenty of myths about climate. Among the most overused and, if possible, most dangerous, is the claim that the climate on our planet has always changed: long periods of extreme heat would have been interrupted by long periods of extreme cold, and so on. "But you only need to study the graphs showing temperature trends to realise that during the Holocene – the most recent geological epoch in which human society as we know it today developed – we had a fairly stable climate for around 12,000 years. In recent decades, however, we have witnessed a genuine spike in temperatures, a sudden shift: this is the big novelty, and the most alarming one." In short, to those who argue that the Earth's climate has always changed, the answer should be: "Of course it has always changed, but the issue is the speed at which it is changing now. We need to understand the cause-and-effect relationship in order to try to grasp the problem and equip ourselves with the tools to tackle it."

Why weather and climate are not the same thing

For those who work on these issues every day, the picture is clear. But confusion still often arises over basic concepts, such as the difference between weather and climate. "In fact," Giacomin points out, "these are terms that are frequently used as synonyms, almost as if they were interchangeable. In reality there are important differences that help us interpret what is happening." Meteorology, in fact, "seeks to describe and determine the possible evolution of the atmosphere, which is nothing other than the evolution of the weather. For instance, it tries to understand how the atmosphere might evolve over the coming hours through deterministic equations, allowing for possible errors: it is something that speaks in the short term, from now to just a few days' time." Climatology, by contrast, "has more statistical than deterministic foundations – suffice it to say that establishing an average requires at least 30 years of accumulated data." It is therefore always worth bearing in mind that a single meteorological event, or even a single season, does not determine a climate trend.

Human activities and global warming: a now-established link

Then there is the overarching issue of the link between human activities and global warming. A relationship that appears to be firmly established, yet there are those who continue to downplay it. And yet "the issue has now been settled by the scientific community. Science is built on doubt and rightly debates everything, but this correlation has now been demonstrated experimentally as well." And in the latest report by the Intergovernmental Panel on Climate Change (IPCC), this correlation is described as unequivocal: "It is rare to find the concept of unequivocality within scientific texts, which goes to show the need felt by the international scientific community to leave no further room for doubt – which is, after all, one of the main drivers of inaction." On these issues, scientific consensus now exceeds 99 per cent and it is "on this figure that one must dwell if one wants a clear picture of things."

A few figures…

• 70% of extreme weather events are linked to climate change. (CarbonBrief)

• Over the past 50 years, a total of 2 million people have lost their lives as a result of extreme weather events, predominantly in the world's poorest countries. (WWF)

The ecological transition is the solution

Denying the link between human activities and climate change often translates into denying the usefulness of the ecological transition. A transition that, on the contrary, "is an important part of the solution," Giacomin states. In essence, scientific data should be used to acknowledge the problem and to think about solutions and truly sustainable development "of our society and our economies, achieved through improvements in infrastructure and efficiency – with regard, for example, to buildings and mobility."

The decisive role of the mobility sector

The sector's impact on a changing climate is not negligible. "The mobility sector," Giacomin explains, "has a significant impact both in terms of climate-altering gas emissions and pollutants." The distinction is substantial: in the first case, we are talking about emissions capable of disrupting the energy balance in the atmosphere (the so-called greenhouse gases – CO2, but also methane), while in the second case we are dealing with gases that are harmful to health when inhaled, such as fine particulate matter and nitrogen dioxide. In terms of production and use, "mobility has an impact on both, especially in certain areas such as the Po Valley, which has a particular geographical conformation as well as being densely populated and highly productive."

As for the electric car, debate has repeatedly focused on the origin of the energy used to power it – whether from renewable sources or, for example, from a thermoelectric power plant running on fossil fuels. "It is true that an electric vehicle can shift the problem of climate-altering gases only marginally if it is powered by energy produced from fossil fuels, even though the efficiency constants of a thermoelectric power plant are considerably higher than those of the combustion engine in an internal combustion car; but it is equally true that the shift is substantial in terms of pollutant gases: it may run on energy produced from fossil fuels, but wherever it travels it does not pollute – so one of the two problems is essentially eliminated."

Read the full version of the chapter at this link.