The instrumental climate record is the cultural heritage of humankind, the result of the diligent work of many generations of people all over the world. However, the changes in the way in which temperature is measured, as well as the environment in which weather stations are located can produce spurious trends. An international study carried out by researchers from the Universitat Rovira i Virgili (URV), the State Meteorology Agency and the University of Bonn (Germany) have succeeded in identifying the most reliable methods that help correct these trends. These “homogenization methods” are a key step in converting the enormous effort made by observers into reliable data about climate change. The results of this research, funded by the Spanish Ministry of Economy and Competitiveness, have been published in the Journal of Climate of the American Meteorological Society.
Climate observations can often be traced back more than a century, even before there were cars and electricity. These long periods of time mean that it is practically impossible to maintain the same measuring conditions over the years. The most common problem is the growth of cities around urban weather stations. We know that cities are getting warmer and warmer because of the thermal properties of urban surfaces and the reduction of evapotranspiration surfaces. To verify this, it is sufficient to compare urban stations with nearby rural stations. Although less known, similar problems are caused by the expansion of irrigated crops around observatories.
Read more: University of Rovira | Virgili
Javier Sigró and Manola Brunet (Photo credit: URV)