Loftslagshækkun

Loftslagshækkun is a term describing the long-term increase in the Earth's average surface temperature and associated changes in the climate system. The word combines loftslag (climate) with hækkun (increase). In practice, it is closely linked to global warming and climate change, the result of enhanced greenhouse gas concentrations in the atmosphere and other forcings.

Causes: The main drivers are anthropogenic emissions of carbon dioxide, methane and nitrous oxide from burning fossil fuels, industry, and agriculture; land-use changes; and feedbacks such as ice-albedo and water vapor. Natural factors include volcanic activity and natural climate variability, but human influence dominates the recent trend.

Measurement: Evidence comes from instrumental records, paleoclimate data and climate models. Global mean surface temperature has risen roughly 1.0–1.2°C since the late 19th century, with most warming in the last few decades. Other indicators include ocean heat content, melting ice, and rising sea level.

Impacts: Warming affects weather extremes, precipitation patterns, ecosystems, agriculture, and human health. Regions experience more intense heatwaves, heavier rainfall, droughts in some areas, and higher sea levels threatening coastal communities.

Responses: Mitigation aims to reduce greenhouse gas emissions and remove CO2 from the atmosphere, while adaptation strengthens resilience to unavoidable changes. International agreements, national policies, and technological shifts toward low-carbon energy are central to addressing loftslagshækkun.