Members of the World Meteorological Organization (WMO) and the US National Centers for Environmental Information (NCEI) have published comprehensive climate data sets after a massive two-year effort.
The updated information from more than 140 countries and thousands of locations is the climate equivalent of a census and is vital to monitoring climate change and for climate-sensitive sectors.
To assess whether a given day, week, month or year was warmer or wetter than average, WMO uses 30-year baseline averages, known as Climatological Standard Normals (CLINO).
NCEI has just issued the new WMO CLINOs 1991-2020 to replace the previous baseline of 1981-2010. Additional countries will still be submitting their updates in the coming months. WMO recommends that the CLINO be updated every decade to better reflect the changing climate and its influence on our day-to-day weather experience.
“Rising atmospheric concentrations of greenhouse gases are changing Earth’s climate much faster than before. As a result, decision makers in climate-sensitive sectors and industries such as water management, energy, health, agriculture and viticulture could be basing important decisions on information that may be out of date,” said Dr Omar Baddour, chief of climate monitoring at WMO.
“Thus it is necessary to update the CLINOs for operational services for decision making, for example for forecasts of peak energy loads and recommendations on crop selection and planting times,” he said.
The World Meteorological Congress recommended that the new 30-year baseline be adopted globally and pledged support to members to help them update their figures. NCEI’s new publication is in line with that recommendation.
“Today’s increasingly powerful computers and climate data management systems make it much easier to conduct more frequent updates, which involve analyzing massive amounts of climate data,” said Peer Hechler, a WMO scientist involved in updating the norms.
“Another advantage of decadal updates is that they will make it possible to incorporate data from newly established weather stations into the normals more rapidly. But for developing countries, which have significant gaps in their data collection and processing capacity, this poses a real challenge.”
For historical comparison and climate change monitoring, WMO still recommends the continuation of the 1961-1990 period for the computation and tracking of global climate anomalies relative to a fixed and common reference period.
For the purpose of the Paris Agreement on climate change and its temperature targets, WMO also uses the 1850-1900 period as a pre-industrial baseline for tracking global temperature increase in its annual State of the Global Climate report. The average global temperature in 2022 was about 1.15 °C above the pre-industrial baseline.
It is anticipated that additional members will submit updated CLINO data in the coming months and WMO will publish the complete update in 2024.