Nearly half of the world's population is "highly vulnerable" to climate change that has already caused widespread damage

With one eye still on the historic pandemic and the soul shrinking from the open war in the heart of Europe, it is difficult to focus attention again on the climate crisis in which humanity has put itself and the planet.

But the warnings about this problem, which will be left as a legacy to future generations, are increasingly forceful and do not refer only to tomorrow, but also to what has already happened.

"The accumulating scientific evidence is unequivocal: climate change is a threat to human well-being and planetary health."

It is not just anyone who warns, it is the conclusion of the group of 270 scientists from 67 countries who have reviewed more than 34,000 articles for the UN to lay the foundations on the impacts that warming is already causing.

The experts of the IPCC (Intergovernmental Panel on Climate Change) are right now in a process of reviewing and updating all the scientific knowledge on warming – the last time it was done was eight years ago.

In August, the first of the reports was published, referring to the physical bases of climate change, and this Monday the second installment, focused on the impacts, will be released.

The analysis concludes that "human-induced climate change" has already caused "widespread adverse impacts" on nature and people.

The negative effects are seen "in all sectors and regions", although the "most vulnerable" are much more affected.

For example, between 3,300 and 3.

600 million people - nearly half the world's population - now live in contexts considered "highly vulnerable" to climate change, either because of their geographical location (for example, the small Pacific islands at risk of disappearing) or because of their poor socio-economic situation, which makes them suffer more from the consequences of extreme weather events.

Or by the combination of both factors, as explained by Marta Rivera-Ferre, a specialist in agroecology and one of the authors of the report.

"Not all people are equally vulnerable to climate change," she adds.

Or by the combination of both factors, as explained by Marta Rivera-Ferre, a specialist in agroecology and one of the authors of the report.

"Not all people are equally vulnerable to climate change," she adds.

Or by the combination of both factors, as explained by Marta Rivera-Ferre, a specialist in agroecology and one of the authors of the report.

"Not all people are equally vulnerable to climate change," she adds.

The experts of the IPCC, an institution created under the umbrella of the UN in 1988, confess eight years after the last major review that they fell short in their forecasts: “The scope and magnitude of the impacts of climate change are greater than expected. estimated in previous evaluations”.

In addition, they note that "some losses are already irreversible", such as the first extinctions of species that are taking place due to warming.

“Other impacts approach irreversibility”,

adds the report in reference to the retreat of glaciers, changes in mountain ecosystems and the loss of permafrost (the permanently frozen soils of arctic regions).

The August report represented a paradigm shift, because it left no room for doubt about the unequivocal responsibility of human beings for warming and the increase in adverse weather events.

This second installment, whose general conclusions have been agreed in the last two weeks with the representatives of the almost 200 countries present at the UN climate negotiations, now focuses on the red zones of this crisis and on adaptation.

The final report specifies that “the global hotspots of high human vulnerability are found particularly in West, Central and East Africa, South Asia, Central and South America, the small island developing States and the Arctic”.

This has a terrible numerical translation: “Between 2010 and 2020, human mortality from floods, droughts, and storms was 15 times higher in highly vulnerable regions, compared to regions with very low vulnerability.”

The current drought in the Horn of Africa has pushed 13 million people into severe famine.Michael Tewelde (AP)

“I have seen many scientific reports in my life, but nothing like this,” said António Guterres, UN Secretary General, on Monday, who has defined the IPCC study as “an atlas of human suffering.”

But this study is not only a count of the damage already produced, it also proposes future scenarios depending on the level of warming that is reached, something that is still in the hands of human beings.

Greenhouse gas emissions expelled by man since the Industrial Revolution, when the massive use of fossil fuels began, have already led to an average warming of 1.1 degrees compared to pre-industrial levels.

And the planet is headed in the short term towards 1.5.

"Each tenth of a degree of increase increases the impacts," says José Manuel Moreno, Professor of Ecology and another of the authors who have participated in the report.

For example, the IPCC warns that as the Earth warms, the availability of fresh water is reduced;

if it reaches 4 degrees,

that water loss would be multiplied by two.

Something similar occurs with the damage caused by floods: the impacts due to this extreme phenomenon will be multiplied by up to 3.9 times if the warming reaches 3 degrees compared to what would happen in a scenario of 1.5 degrees.

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To limit the increase in temperature and not exceed the goal of 1.5 established by the Paris Agreement, a “fast and deep” cut in greenhouse gases is needed, recalls Thelma Kurg, vice president of the IPCC.

Postponing these cuts and adaptation measures means losing "a brief window of opportunity" that is closing "to ensure a livable and sustainable future for all," according to the report.

Riverra-Ferre adds: "The cost of inaction is greater than that of action."

Food security and migrations

The report reviews the impacts already produced by sectors and geographical areas.

It stresses, for example, that food security and access to fresh water have been reduced by the increase in extreme weather events.

"The yield of rice, corn and wheat crops has fallen by 5%," says Rivera-Ferre.

This type of damage exposes millions of people to malnutrition, warns the IPCC.

In addition, an increase in diseases and a deterioration in mental health linked to global warming has been detected.

And the adverse economic impacts linked to this crisis are growing.

The IPCC analysis warns that “climate change is contributing to humanitarian crises”: it is “increasingly driving the forced displacement” of people in all regions.

Species extinction

The planet is currently experiencing a process of extinction of local populations of plants and animals, which disappear from historical areas of distribution and move to others.

In 47% of the 976 species examined in the report, this local disappearance is associated with an increase in temperature.

Jofre Carnicer, a biologist and another of the IPCC researchers, also points to the complete disappearance of species that has already been directly attributed to climate change: a subspecies of the marsupial

which was practically wiped off the map after several heat waves in Queensland, Australia.

Or the mosaic-tailed mouse (

), which was officially declared extinct in 2016 due to rising sea levels in the Pacific.

Forecasts in this field are not good either.

According to the IPCC report, between 3% and 14% of the species of terrestrial ecosystems that have been analyzed will be at a very high level of risk of extinction if warming reaches 1.5 degrees.

If 3 degrees are reached, the risk will be multiplied by two.

And by 3.5 if the heating rises to 5 degrees.

unsustainable development

One of the things that is clear throughout the study is that the impacts of global warming do not only have to do with rising temperatures and extreme events.

Socioeconomic conditions and the growth model influence.

“Current patterns of unsustainable development are increasing the exposure of ecosystems and people to climate hazards,” the report emphatically states.

In addition, it is added that in the last eight years evidence has accumulated that indicates that "the degradation and destruction of ecosystems by humans increases the vulnerability of people" to warming, and problems such as the deforestation or pollution.

Hans-Otto Pörtner, the co-chair of the IPCC group that has prepared this second chapter, sums it up this way: "Healthy ecosystems are more resistant to climate change and provide critical services for life, such as food and clean water."

That is why one of the formulas to face this problem is to "restore degraded ecosystems" and try to effectively protect between 30% and 50% of terrestrial and marine ecosystems.

Bad habits

In addition to cutting emissions, scientists point out that rapid and ambitious action is needed to adapt to the effects of warming.

But “progress on adaptation is uneven” and, again, the populations with the lowest incomes are the ones that are furthest behind.

The analysis also points out the risks of some adaptation policies and emission cuts, which can have secondary effects.

For example, it warns against afforestation in areas that are not historically forested or biofuels, which can "aggravate climate-related risks to biodiversity, water and food security."

Deeper droughts and coastal flooding in the Mediterranean

Extreme episode of acqua alta in Venice in November 2019. Marco Bertorello / AFP

"The Mediterranean is a hot spot for the advancement of climate change," warns biologist Jofre Carnicer, who has participated in the chapter of the IPCC report referring to this region, which includes the Iberian Peninsula.

This area is warming up faster than the average for the planet: if on average the Earth has reached a 1.1 degree increase in temperature, in the Mediterranean it is already 1.5.

One of the consequences that most worries experts is the lack of fresh water.

"In southern Europe, more than a third of the population will be exposed to water scarcity if it reaches 2 degrees," says the IPCC report.

If 3 degrees are reached, the risk will double and "significant economic losses are expected in sectors dependent on water and energy."

Carnicer explains that for each degree of increase, a 4% reduction in rainfall is expected in the Mediterranean.

Another of the impacts that worries experts is that referred to coastal flooding.

In Europe, it is expected that the damage linked to this phenomenon will increase "at least 10 times by the end of the 21st century." "The rise in sea level represents an existential threat to coastal communities and their cultural heritage," says the report in reference to cases such as that of the Italian city of Venice.In the Mediterranean region alone, 42 million people live in low-lying coastal areas, which are highly exposed to a rise in sea level, adds Carnicer. 

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