Climate change refers to a long-term shift in global or regional temperature and weather patterns. While Earth's climate has always varied naturally (ice ages, warm periods), the term today overwhelmingly refers to the rapid warming since the mid-20th century, driven primarily by human emissions of greenhouse gases — mainly CO₂ from burning fossil fuels, methane from agriculture and leaks, and nitrous oxide from fertilisers. The global mean temperature has risen approximately 1.2 °C above pre-industrial levels as of the 2020s.
The consequences are already visible and measurable: glaciers retreating worldwide, Arctic sea ice declining by 13 % per decade, sea level rising (~3.7 mm/year and accelerating), heatwaves becoming more frequent and intense, precipitation patterns shifting (wet regions getting wetter, dry regions drier), and extreme weather events intensifying. The ENSO cycle may be affected, and the jet stream appears to be weakening, potentially causing more persistent blocking patterns.
In Spain and the Mediterranean — identified as a climate change "hotspot" by the IPCC — projections indicate 2–4 °C warming by 2100 (under moderate scenarios), significant rainfall decreases (especially in the south), more extreme DANA events, longer and more intense heatwaves, increased wildfire risk, and rising sea levels threatening coastal areas. The Paris Agreement aims to limit warming to 1.5–2 °C, requiring drastic emission reductions. Meteorological monitoring through global observation networks and climate models is essential for tracking change and informing adaptation strategies.