we risk 3.5 degrees more – Corriere.it

There is no longer any doubt. Anthropogenic emissions, fueled by our dependence on fossil fuels, are wreaking havoc on planet Earth and the plans adopted so far are not enough to avert the worst: extreme events, floods, persistent droughts, rising oceans. «Human activities have unequivocally caused global warming», the IPCC Summary Report establishes without ifs and buts – the UN scientific forum – released today after a weekend of frantic debates between leading climate scientists and political negotiators. A fundamental report because it will become the “roadmap” for the fight against climate change between now and 2030. «The climate bomb marks the seconds. But today’s IPCC report is a practical guide to defuse the climate time bomb,” comments UN Secretary General Antonio Guterres.

In the final document of the IPCC (International panel on climate change), over 1,000 scientists working for the United Nations sound yet another alarm, but leave a glimmer of hope open: “If we act immediately, there are multiple, feasible and effective options for reduce greenhouse gas emissions»

The work of the Sixth Evaluation Report (here the site with the official document), which involved over a thousand scientists from all over the world, lasted for eight years and ended last Sunday in Switzerland with the approval of the Evaluation Report Synthesis. Among many alarming data, the final message tries the path of optimism: “Urgent climate action can ensure a livable future for all – assures the final press release -. There are multiple, feasible and effective options to reduce greenhouse gas emissions.” But we need to change gears immediately: “The pace and scope of what has been done so far and the current plans are insufficient to tackle climate change”.

Already reached the average of + 1.1 ° C

The starting point is unequivocal. Global surface temperature reached 1.1°C above industrial temperatures in 2011-2020. Greenhouse gas emissions have continued to increase due to “the unsustainable use of energy, of one’s own and of the territory”. They were equal to 59±6.6 GtCO2-eq in 2019, about 12% more than in 2010 and a good 54% more than 1990. Their impact has caused «widespread and rapid changes in the atmosphere, ocean, cryosphere and in the biosphere”.

Some are obvious to all. For example, the extreme weather and climatic events, “present in every region of the world”. Others, such as sea level rise, are scientifically measurable. “The global mean sea level increased by 0.20 m between 1901 and 2018 – reads the report -. The mean rate of sea level rise was 1.3 mm per year between 1901 and 1971, increasing to 1.9 mm per year between 1971 and 2006, and with further increase to 3.7 mm per year between 2006 and 2018». Human activities are “most likely” the main driver of these increases, “at least since 1971”. And man is also the trigger for the tumultuous increase in extreme events, starting in the 1950s, “including the increase in the frequency of heat waves and droughts”.

3.6 billion people at risk

No one escapes the climate crisis, but often it is the communities that have historically contributed the least to emissions that today find themselves in the most vulnerable situations and with populations at the mercy of nature in tilt. About 3.3–3.6 billion people live in highly vulnerable contexts. «In the last decade, i deaths from floods, droughts and storms were 15 times higher in highly vulnerable regions». A highly unequal world, even in the climate challenge. The 10% of households with the highest per capita emissions contribute 34-45% of all household emissions, while the bottom 50% contribute only 13-15%.

Five scenarios: how they change

If this is the photograph of the planet today, the report identifies five scenarios for the future. With only one certainty: «the current plans are still insufficient». Global warming will continue to increase in the short term (2021-2040) in all scenarios considered, also due to accumulated CO2 emissions. That’s how it is for scientists ‘probable’ that global average warming will break the +1.5°C barrier during the 21st century and also that it will be difficult to limit it below 2°C, the minimum objective of the Paris agreements signed in 2015. There is still too much reliance on fossil fuels and the financial flows destined for the fight against climate change “do not reach the necessary levels in all sectors and regions”. On the other hand – this is the main message to policy makers –all is not lost: «Deep, rapid and sustained reductions in greenhouse gas emissions would lead to a significant global warming slowdown within about two decadesand also to discernible changes in atmospheric composition in some years.”

The challenge of zero emissions in the energy field

The IPCC report lists many possible ways to limit the damage. The watchword is “Climate resilient development”first of all in the energy field through zero emission systems, a substantial one reduction of overall fossil fuel use, utilization of carbon capture and storage, widespread electrification, savings and energy efficiency. But also with radical changes in the food, transport, industry, construction and land sectors. “Urban areas offer a global-scale opportunity for ambitious climate action,” the report points out, which also shows encouraging signs. For example, the drastic reduction in the cost of energy production from alternative sources. “From 2010 to 2019 there were sustained decreases in the unit costs of solar energy (85%), wind energy (55%) and lithium-ion batteries (85%)”confirm the report.

Hard the call of UN Secretary General Antonio Guterres to energy companies: «I call on the CEOs of all oil and gas companies to be part of the solution, by presenting credible, complete and detailed transition plans in line with the recommendations of our high-level expert group on net zero commitments» he said in a message accompanying the launch of the Intergovernmental Panel on Climate Change report.

The factors that most concern Italy

Italy is certainly not immune from the darkest scenarios. Scientists predict that heat waves and droughts will become more frequent. Due to sea level rise, it is also expected that current extreme marine events will occur at least once a year in more than half of all seaside locations by 2100 and in all five scenarios analyzed. In fact, the rising sea level is «an inevitable phenomenon for the next centuries and millennia due to continued warming of the deep oceans and melting ice sheets, And sea ​​levels will remain elevated for thousands of yearsHowever, deep, rapid and sustained reductions in greenhouse gas emissions would limit the further acceleration of sea level rise. “The IPCC report is unequivocal about the serious consequences that the climate crisis has already caused,” commented the Vice-President of the European Commission Frans Timmermans —. It should be the basis for increased ambition in COP28 with updated nationally determined contributions, continued phase-out of fossil fuels, robust domestic policies to get the job done, as global emissions will peak by 2025.” .

The Great Thaw and the Arctic and Antarctic ice sheets

The most chilling alarm, although supported by “limited evidence” for now, concerns the Great Thaw. “At levels of warming between 2°C and 3°C, the Greenland and West Antarctic ice sheets will be lost almost completely and irreversibly for several millennia, causing several meters of sea level rise – supports the report, which does not even exclude a « average sea level rise of 2 meters by 2100 and more than 15 meters by 2300 in the worst-case scenario of very high greenhouse gas emissions.

“Globally we need to reach peak emissions by 2025, to avoid a overshoot (a temporary increase in temperatures over 1.5°C). The greater the entity and duration of this overshoot, the more ecosystems and societies will be exposed to greater and more widespread impacts and risks – comments Lucia Perugini of the CMCC -. We are on the road leading to an increase in the global average temperature which can reach 3.5°Cand this poses a threat to humanity as a whole.”