Water shortages, absence of drinking water, multiplication of droughts and floods… Billions of people are already affected by water-related problems, with an “imminent” risk of a global crisis.
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Here are the main figures compiled by the UN-Water platform which publishes its report on the occasion of the opening of a conference on water in New York on Wednesday.
Shortages
Water use has increased approximately 1% per year worldwide over the past 40 years.
To meet this thirst, humans turn to groundwater with sometimes excessive extractions: between 100 and 200 km3 of underground water reserves are depleted each year.
About 10% of the world’s population lives in a country where water stress (the relationship between water use and its availability) reaches a high or critical level, “significantly” limiting the availability of water for the needs of people.
And according to the report by UN climate experts (IPCC) published on Monday, “about half of the world’s population” suffers from “severe” water shortages for at least part of the year.
According to the World Bank, these water shortages reinforced by climate change could cost in some regions up to 6% of GDP by 2050 due to impacts on agriculture, health, income, and potentially migration. forced or even conflicts.
City versus agriculture
Agriculture uses more than 70% of the world’s water resources, but with demand from cities expected to increase “by 80% by 2050, supplying water to urban centers from rural areas has become a strategy current” to meet these new needs, notes the UN.
But that shouldn’t be enough. The number of urban dwellers at risk of water shortages is expected to rise from 933 million in 2016 to between 1.7 and 2.4 billion in 2050, according to UN-Water, which notes that India is expected to be the most seriously affected country.
Extremes
With global warming, the humidity in the atmosphere increases by about 7% for each additional degree, leading to more, more intense and less regular precipitation.
Between 2000 and 2019, floods are estimated to have caused $650 billion in damage, affected 1.65 billion people and caused more than 100,000 deaths, according to the report.
Warming also multiplies droughts which, over the same period, affected 1.43 billion people and caused 130 billion dollars in damage.
Together, droughts and floods account for more than 75% of natural disasters experienced by humanity.
Sanitation and hygiene
In 2020, 2 billion people (26% of the population) were still without safe drinking water and 3.6 billion (46% of the population) did not have access to safely managed sanitation services , 494 million of whom had no choice but to defecate in the open.
Also in 2020, more than 40% of domestic wastewater was not safely treated before being discharged into the environment.
In addition, 2.3 billion people (29% of the world’s population) lacked basic sanitation services, including 670 million without any handwashing facilities. And at least two billion people drink water contaminated with feces.
Conditions conducive to the spread of cholera, dysentery, or polio. In 2019, 1.4 million deaths were reportedly caused by the lack of adequate hygiene and sanitation services.
But the risks also come from emerging pollutants such as pharmaceuticals and chemicals, pesticides or nanomaterials.
Ecosystems
This pollution also affects freshwater ecosystems, victims in particular of agricultural runoff.
These ecosystems are “among the most threatened in the world”, notes the report, which mentions in particular the disappearance of more than 85% of wetlands.
And “the loss of environmental services and biodiversity is expected to continue as natural areas disappear in favor of cultivated land”. With the risk of causing “considerable” greenhouse gas emissions when peatlands are “drained and converted to cropland”.
Funding
Estimates are difficult, but a study cited by the report puts the investment needed to achieve the UN’s sixth “Sustainable Development Goal” on water and energy at more than $1 trillion per year by 2030. sanitation for all.
In particular, to guarantee universal and equitable access to a supply of drinking water by 2030, it would be necessary to multiply by three the current levels of investment.