For nearly twenty years I have been telling that fossil fuels were leading us to disaster and we needed to change course. At first, the interest in the subject was close to zero: at most you would be invited to cultural centres or schools where the organisers were considered a little naive. On some occasions I remember speaking to no more than five or six people, spending the night under a deluge of questions. I cannot forget a heavy attack on the Corriere della Sera [a popular Italian newspaper] to Luca Mercalli after he had interviewed me in a broadcast on RAI 3. It was unfortunate that the so-called "Sunday catastrophists" had such a stage in the media, paid for with public money.

In recent years, however, attention has grown, slowly but steadily, and finally 2021 has arrived, the year of the Big Bang. Today authoritative world leaders repeat over and over: "We have no more time"! Welcome to the real world, an "overturned" world in which the hippies of the past are heavily sought after: governments, international agencies, companies, foundations, NGOs, trade associations, parties, trade unions, TV, radio, newspapers, social networks, individual citizens, everyone is looking for them. The questions are always the same. How to get out of our reliance on fossil fuels? Will renewables be enough? Is the electric car a good idea? What about hydrogen? And nuclear power? Well, we have already said and written everything about this, and it is easy to find. The important question, however, the one that few ask, is another: will we make it, before the climate catastrophe overwhelms us?

One common, overriding concern is that there are not enough materials on Earth to make the energy transition: lithium, nickel, silver, rare earths... These concerns should be calmed down, as the renewable civilization will consume far fewer materials than the fossil. Here is an example: to make one megawatt (MW) of silicon photovoltaic (PV) panels, 200 tons of materials are needed, and one MW of PV produces 40,000 MWh of electricity in thirty years. It takes 14,000 tons of coal to produce the same amount of electricity, over 70 times more. Furthermore, PVs are recyclable, unlike what happens with fossil fuels, which are dispersed in the atmosphere as CO2. Similar conclusions are obtained by comparing other fossil fuels and renewable technologies.

However, the problem that keeps me awake at night, much more than the material availability, is yet another. Which one? Italy must add 70 GW of renewable electricity between now and 2030 to its current capacity. Similarly, all countries around the globe should make similar efforts. Assuming that each nation (there are 200!) installs an average of 20 GW of PV (I keep it to low estimates), within a decade we need 4000 GW. In other words, in the period 2020-2030 we have to produce 6 times more solar panels than in 2010-2020. Similar estimates can be made for lithium, whose production is expected to increase by about 20 times. To dramatically increase the production of materials and devices for the conversion and accumulation of renewables in the span of a few years is a crazy challenge: it is necessary to carry out geological investigations, obtain permits, extract minerals, refine them, build huge factories for manufacturing. To do all this you need a commodity that cannot be bought on the market: time.

The alarm for the transition was sounded by a catastrophe that has caused more than five million deaths to date. Unfortunately it went exactly as we feared in those evenings between a few close friends: humanity woke up only when it was cornered. Too bad we wasted time grinning as the catastrophe built up and progressed. Having 20-25 years instead of 10 would have made a huge difference. Now it will be very hard, but we have no choice. We have to try, running with all our energy. Will we make it?

This article also appeared on Sapere in Italian. Energy Voices is a democratic space presenting the thoughts and opinions of leading Energy & Sustainability writers, their opinions do not necessarily represent those of illuminem.