GLOBAL CLIMATE CONDITIONS IN 2023

Abstract

2023 was the warmest year on record; the temperature was 1.45°C above the pre-industrial average. The concentrations
of the three main greenhouse gases – carbon dioxide, methane and nitrous oxide – reached record-high
observed levels in 2022, and real-time data show that levels continued to increase in 2023. The global mean sea
level also reached a record high. The rate of sea-level rise in the past 10 years has more than doubled since the first
decade of satellite observations. Antarctic sea-ice extent reached an absolute record low in February. The annual
maximum extent was about 1 million km2 below the previous maximum record low. The reference glaciers experienced
the largest loss of ice on record, driven by extremely negative mass balance in both western North America
and Europe. Glaciers in Switzerland have lost about 10% of their remaining volume in the past two years. Extreme
weather continued to lead to severe socioeconomic impacts. Extreme heat affected many parts of the world. Wildfires
in Canada, Europe and Hawaii led to loss of life, the destruction of homes and large-scale air pollution. Flooding
associated with extreme rainfall from the Mediterranean Cyclone Daniel affected Greece, Bulgaria, Türkiye and
Libya, with particularly heavy loss of life in Libya.