Climate Risks: Points of No Return Are Getting Closer and Closer

 Climate Risks: Points of No Return Are Getting Closer and Closer

An IPCC scientist says it clear and loud: “We cannot ignore some points of no return in the climatic system, therefore we need to use a careful approach in the phase of transition that we find ourselves about to face.”

By Roberto Barbiero

Translation: Silvia Bellavite

In support of the negotiations that are taking place in these first days of COP26, the main scientific institutions have made public the great deal of reports about the conditions of global climate and the sceneries that lie ahead. It is a succession of worrying and dramatic news that constitute the last straw which should push towards a rapid and renewed action the various countries’ delegates, already locked in the many rooms, busy with the complex debates of these negotiations that promise to be the most difficult ones in the history of COPs.

Among the scientific reports, emerges that of the Intergovernmental Panel of Climate Change (IPCC), which constitutes the most up-to-date and complete point of reference for the modern knowledge of climate change: Climate Change 2021: the Physical Science Basis

An important reflection on this report’s role has been provided by Johan Rockström, director of the Potsdam Institute for Climate Impact Research in Germany, while discussing on the “Emerging climate risks and what will it take to limit global warming to 2.0°C” (“Rischi climatici emergenti e cosa servirà per limitare il riscaldamento globale a 2.0°C”) in the framework of a debate promoted in Glasgow by the World Meteorological Organization (Organizzazione Mondiale della Meteorologia) (WMO) as a side event to COP26. The IPCC report, as Rockström underlines, shows the giant steps forwards made by climate science on the climate risks we have to face. The 1,1°C rise in global temperature with respects to the pre-industrial era brings with itself an increase of extreme events and climate risks that will impact natural systems, specifically the ecosystems and biodiversity, oceans and the cryosphere, with socio-economic consequences on the human communities that appear to be particularly worrying in light of the expected sceneries, particularly if we won’t be able to restrict the warming below 2°C before the end of the century.

These are the two key points on which Rockström’s considerations are built. To begin with, for the first time ever in an IPCC report, it is stated that “tipping points in the climate system can no longer be excluded, so a very precautionary approach is needed in the transition phase we are facing”. In fact, among the fifteen tipping points recognized with respect to the Earth system, there are nine that show signs of evident instability, including, for instance, the loss of ice in the Arctic and Greenland, the loss of coral barrier, the reduction of the boreal and amazonian forests.

We are moving from a relatively stable climate system to an increasingly less stable one, it cannot yet be said to be catastrophic, but we are moving on the wrong path”, spiega Rockström.

Key-element of the new IPCC report, however, is not so much the knowledge of the  physical processes of the single unstable elements, or tipping points, it is more about their interconnection, since the gravity of an hypothetical cascade effect’s consequences. For instance, the rapid melting of Greenland’s ice could lead to a weakening of the oceanic Atlantic circulation, which in turn has an impact on the Amazonian rainfalls, thus making drought conditions more frequent in the area. The danger these cascade effects would imply is potentially enormous, therefore it will be subjected to further studies and research.

Climate tipping points that could be reached in this century due to human activity (Lenton et. al., 2019, Nature)

The second point underlined by Rockström refers to the international community that stands in front of him, in order to achieve the goal of net zero emissions by 2050.

In the decarbonisation processes’ simulations and their relative timescales, “climate models are assuming that the current absorption capacity of natural systems will continue stably in the future as well as the carbon storage capacity of forests, soils, permafrost and wetlands. We are therefore assuming that biological systems do not go through tipping points“. But what if that were to happen? The consequences could be even worse than those imagined until now.

We must act fast to preserve and protect natural systems on one hand and to break down greenhouse gas emissions on the other.

In the face of the political action’s weakness and the inadequacy of the renewed ambitions concerning the greenhouse gas emissions’ reduction (that, even if made real, would still lead to an approximately 2,7°C increase by the end of the century), scientists admit that to limit global warming to 1,5°C does not appear to be plausible at the momentand that to stabilise the average global temperature at the end of the century below the 2°C compared to the pre-industrial data will require a dramatic social transformation. There are no more excuses for the actors of the political world to ignore or misunderstand the urgency of getting into immediate action.

A climatic scenery that, in the meantime, does not show mercy. The provisory report on the “State of the Global Climate 2021”, based on data from the first nine months of the year and presented in Glasgow by WMO, highlights unequivocally how the latest new record on greenhouse gas concentrations and the continuous warming of the Earth have “pulled the planet into unexplored territory, with repercussions of great entity for today and future generations”.

2021 is nowadays projected to be “just” from the fifth to the seventh warmer year ever recorded, thanks to the influence of a moderate La Niña at the beginning of the year.

La Niña has a temporary cooling effect on the average global temperature and influences weather and climate at regional level. But this does not deny or invert the rising tendency in temperature in the long term.

The difference in average global temperatures from the pre-industrial era (1850-1900) via six data sets of global temperature [HadCRUT. (UK Met Office), NOAAGlobalTemp v5 (USA), NASA GISTEMP v4 (USA), Berkeley Earth (USA), ERA5 (ECMWF), JRA-55 (Japan)]

The preliminary report underlines the impressive number of extreme or atypical meteorological events that marked the past months, provoking damage to natural systems and human communities.

Exceptional heat waves struck North West America and the United States in June and July. The 29th of June in Lytton, Canada, we hit 49,6 °C, beating the former national record. The Death Valley, in California, reached 54,4 °C the 9th of July: the highest temperature recorded in the world at least since the Thirties.

Also in various Mediterranean areas record temperatures were registered and the exceptional heat was often accompanied by devastating fires. The 11th of August an agrometeorological station in Sicily hit 48,8 °C, a temporary european record, while Kairouan (Tunisie) reached a record of 50,3 °C. Extreme rainfalls and floods took place in the Chinese district of Henan in July. The city of Zhengzho the 20th of July received 201,9 mm of rain over the course of a single hour, a national record for China.

In mid-July, western Germany and eastern Belgium suffered from some of the most serious floods ever recorded, with 200 deaths. A strong drought hit the majority of subtropical South America for the second consecutive year, causing damage to many of the regions where Brazil, as well as the United States and Canada, grow coffee plantations, making wheat and rapeseed production collapse.

Events that have damaged crucial ecosystems and made a serious impact on food safety, causing migrations of populations. Particularly critical nowadays is the situation in Ethiopia, South Sudan, Yemen and Madagascar.

“Scientists are clear on the facts. Now leaders need to be just as clear in their actions. The door is open; the solutions are there. COP26 must be a turning point. We must act now – with ambition and solidarity – to safeguard our future and save humanity” declared António Guterres, the General Secretary of the United Nations, ending the presentation of the Report.

All we can do is to wait. In the meantime, the tipping points are getting closer.

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