“CLIMATE ACTION WEEK”: Few important facts about climate change by Roberto Buizza, professor of physics at the Institute of the Life Sciences at the Sant’Anna School, Pisa

by Roberto Buizza

We need to act urgently and do more to achieve a zero-net-emission by 2050, or possibly earlier:

  • We have the technology and the resources to address Climate Change: we have to decide to act, and invest to realize a new industrial revolution, aim for industry 5.0, i.e. a decarbonized industry 4.0.

  • Changes in energy production and energy storage have a key role to play.

  • We need to change the narrative from ‘addressing CC consumes resources’ into ‘investing in industry 5.0 leads to addressing CC and to economic growth’.

  • We should aim for GDP growth at zero-net GHGs emissions.

  • It can be done: estimates puts the requited investments to less than 2% of GDP for the next two decades, to achieve ‘zero net emissions’.


Here are 10 key points that we should take into account:

  1. Observations indicate that the green-house-gases (GHGs) concentration keeps rising at a faster rate, that the climate continues to warm and the Arctic sea-ice extension continues to decrease; note that not only the mean values change, but also the variance: with a warmer atmosphere (and sea-surface-temperature) extreme events can become more intense, and more frequent, and the weather we experience varies more.
  2. Italy is one of the countries hit hardest by weather events, and is located in one of the climate hot-spots: it is in the countries interest to act.
  3. CC has to be addressed urgently because, due to large number of people living on the planet and the continuous rise of the world population, more and more people is/will be affected by CC; the number of climate migrants is very likely to grow 10-100 times, if warming continues.
  4. We (i.e. mankind) are responsible for CC: the anthropogenic impact on the climate is far larger than the Earth climate natural variations (Fig. 2); we need to act on all fronts, since most human activities contribute to CC: for example, globally and on average, electricity production and heating contributes to about 25% of the emissions.
  5. Looking at the CO2 emissions, in absolute terms China is the biggest producer, but a more correct measure that takes into account the right of everyone to access energy and develop, we should look at emissions per-capita: in this respect, the US, Canada, Australia, followed by Europe, are top emitters.
  6. In the past decade, Europe has been reducing its GHGs’ emissions; if we analyse the four European largest countries, we can see that hey achieved this reduction partly by increasing the percentage of renewable energy production, by transforming their economies (as indicated, e.g. by the energy use per GDP production).
  7. Up to today, GDP growth has been coupled with increased GHG-emissions, with periods of economic downturn (e.g. after 2008) characterized by a reduction in the GHGs’ emissions: this link between economic activity/growth and increase in GHGs’ emissions can be detected in many countries, since very few have de-coupled GDP growth with ‘CO2 intensity’.
  8. In Italy, in particular, between 1990 and today the percentage of renewable energy production has increased by a factor of ~ 2 (this is compared to Germany and the UK, for whom the percentages have increased by factors of ~8 and ~ 12, respectively); in terms of GDP, we see that up to date the time evolution of the GDP growth and the change in the percentage of renewables, explain the observed trend in the GHGs’ emissions.
  9. In terms of economic transformation, Italy lags behind other countries such as France, Germany and the UK, who have managed to reduce by a larger factor the CO2 intensity of their economics; considering again the electricity production, if we consider the major CO2 emitters, their percentage of renewable electricity generation is still rather low, at levels of 30% or lower (apart for Canada, for whom it is about 60%); more actions should be taken to increase the percentage of renewables.
  10. We need to act now: such a strong signal was sent to the Italian Institutions in July by 310 scientists expert on climate, the Earth system, the atmosphere and the ocean, mathematics, physics and chemistry, who wrote a letter to the Presidents of the Lower and Upper Chambers (Camera and Senato), to the President of the Republic and the Prime Minister, asking that Italy takes actions to achieve zero-net emissions of GHG by 2050, or even earlier!