Page 105 - India Insurance Report 2023- BIMTECH

India Insurance Report - Series II 93

Figure 2 - Global annual surface temperature anomaly since 1880; Data – NASA, GISTEMP [2]

Global surface temperature anomaly refers to the deviation in the Earth’s surface temperature from
the long-term average. According to climate information from the National Oceanic and Atmospheric
Administration (NOAA) and several other reputed met agencies, Earth’s average surface temperature is
rising. The top 10 warmest years across recorded human history – with reliable records existing since the
th
early 20 century – have all occurred since 2005. Year 2016 was recorded warmest year, closely followed
by 2020 (Fig 2). This noted increase in the global surface temperature anomalies is mainly driven by the
increase in greenhouse gases such as carbon dioxide (Fig 3), methane, and nitrous oxide in the atmosphere.
The abundance of these greenhouse gases traps excessive heat in the atmosphere depending on the various
radiation absorption bands, leading to the greenhouse effect, eventually increasing the Earth’s temperature
[3] . Of note, the CO2 concentration in the atmosphere rose by approximately 50 PPM (Fig 4) in the most
recent period of the 21st century only [4,5] – most of it comes from industrial emissions.

Figure 3 - CO concentration in the atmosphere [4,5] since 1958; Data - Global Monitoring Laboratory (GML)
2
of the National Oceanic and Atmospheric Administration (NOAA)