Rainfall Crisis Could Affect 2 Billion People

A new scientific study warns of changing global rainfall patterns. Nearly 2 billion people could face significant changes in water availability if the average global temperature rises by 1.5°C, even temporarily, warns a new study published in the journal Earth's Future. The research is based on complex climate simulations and is cited by Live Science.

• The Intertropical Convergence Zone, a key climate hotspot

The focus of the study is the Intertropical Convergence Zone - an equatorial region where warm, humid air currents from the northern and southern hemispheres meet, generating heavy rainfall. This zone has a major influence on the seasonal cycles of rainfall in tropical regions. The study's lead author, climatologist Norman Steinert of the Norwegian Center for International Climate Research, says a temporary increase in global temperatures could have a lasting effect on this area, changing the distribution of precipitation in the long term.

• Two scenarios, same conclusion: the danger exists

The study explores two distinct scenarios: An idealized scenario, in which CO₂ concentrations increase for 140 years by 1% per year, then decline at the same rate; and A more realistic scenario, in which emissions increase until 2040, followed by aggressive reductions in response to the effects of warming. Despite methodological differences, both scenarios include simulations that predict a shift in the intertropical convergence zone, which would lead to severe imbalances in precipitation.

• Potential impact: drought, flooding and food insecurity

Changes to this key climate zone could lead to: Reduced rainfall in central and western Africa, as well as in Southeast Asia; Increased flood risk in northeastern Brazil; Agricultural instability in regions that depend on the predictability of wet and dry seasons. According to projections, 23% of the world's population and 12% of the planet's land area could be affected by these changes.

The study authors emphasize that these projections do not represent the most likely future, but they are "plausible” and significant enough to be considered in climate and adaptation policies. The impact, however unlikely, could be devastating for water and food security. "This climate change is not just about higher temperatures,” warns Steinert. "It could completely rearrange the global map of water - the source of life and the backbone of agriculture.”

• Temporary warming can leave permanent marks

Perhaps the most disturbing aspect of the study is the idea that even a temporary increase in global temperatures could have irreversible effects on regional climate. This contradicts the widely held assumption that returning to lower emissions will automatically "reset” global climate systems.